< draft-ietf-manet-dlep-08.txt   draft-ietf-manet-dlep-09.txt >
Mobile Ad hoc Networks Working Group S. Ratliff Mobile Ad hoc Networks Working Group S. Ratliff
Internet-Draft VT iDirect Internet-Draft VT iDirect
Intended status: Standards Track B. Berry Intended status: Standards Track B. Berry
Expires: August 31, 2015 Expires: October 15, 2015
S. Jury S. Jury
Cisco Systems Cisco Systems
D. Satterwhite D. Satterwhite
Broadcom Broadcom
R. Taylor R. Taylor
Airbus Defence & Space Airbus Defence & Space
February 27, 2015 April 13, 2015
Dynamic Link Exchange Protocol (DLEP) Dynamic Link Exchange Protocol (DLEP)
draft-ietf-manet-dlep-08 draft-ietf-manet-dlep-09
Abstract Abstract
When routing devices rely on modems to effect communications over When routing devices rely on modems to effect communications over
wireless links, they need timely and accurate knowledge of the wireless links, they need timely and accurate knowledge of the
characteristics of the link (speed, state, etc.) in order to make characteristics of the link (speed, state, etc.) in order to make
forwarding decisions. In mobile or other environments where these forwarding decisions. In mobile or other environments where these
characteristics change frequently, manual configurations or the characteristics change frequently, manual configurations or the
inference of state through routing or transport protocols does not inference of state through routing or transport protocols does not
allow the router to make the best decisions. A bidirectional, event- allow the router to make the best decisions. A bidirectional, event-
skipping to change at page 1, line 45 skipping to change at page 1, line 45
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This Internet-Draft will expire on August 31, 2015. This Internet-Draft will expire on October 15, 2015.
Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Requirements . . . . . . . . . . . . . . . . . . . . . . 8 1.1. Protocol Overview . . . . . . . . . . . . . . . . . . . . 7
1.2. Requirements . . . . . . . . . . . . . . . . . . . . . . 8
2. Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . 8 2. Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Core Features and Optional Extensions . . . . . . . . . . . . 10 3. Core Features and Optional Extensions . . . . . . . . . . . . 10
3.1. Negotiation of Optional Extensions . . . . . . . . . . . 10 3.1. Negotiation of Optional Extensions . . . . . . . . . . . 10
3.2. Protocol Extensions . . . . . . . . . . . . . . . . . . . 10 3.2. Protocol Extensions . . . . . . . . . . . . . . . . . . . 10
3.3. Experimental Signals and Data Items . . . . . . . . . . . 11 3.3. Experimental Signals and Data Items . . . . . . . . . . . 11
4. Metrics . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4. Metrics . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.1. Mandatory Metrics . . . . . . . . . . . . . . . . . . . . 12 4.1. Mandatory Metrics . . . . . . . . . . . . . . . . . . . . 12
5. Normal Session Flow . . . . . . . . . . . . . . . . . . . . . 12 4.2. DLEP Router session flow - Discovery case . . . . . . . . 12
5.1. DLEP Router session flow - Discovery case . . . . . . . . 13 4.3. DLEP Router session flow - Configured case . . . . . . . 13
5.2. DLEP Router session flow - Configured case . . . . . . . 13 4.4. DLEP Modem session flow . . . . . . . . . . . . . . . . . 13
5.3. DLEP Modem session flow . . . . . . . . . . . . . . . . . 14 4.5. Common Session Flow . . . . . . . . . . . . . . . . . . . 14
5.4. Common Session Flow . . . . . . . . . . . . . . . . . . . 14 5. DLEP Message Processing . . . . . . . . . . . . . . . . . . . 15
6. DLEP Message Processing . . . . . . . . . . . . . . . . . . . 15 5.1. DLEP Signal Header . . . . . . . . . . . . . . . . . . . 16
6.1. DLEP Signal Header . . . . . . . . . . . . . . . . . . . 16 5.2. DLEP Generic Data Item . . . . . . . . . . . . . . . . . 16
6.2. DLEP Generic Data Item . . . . . . . . . . . . . . . . . 16 6. DLEP Signals . . . . . . . . . . . . . . . . . . . . . . . . 17
7. DLEP Signals . . . . . . . . . . . . . . . . . . . . . . . . 17 6.1. Peer Discovery Signal . . . . . . . . . . . . . . . . . . 17
7.1. Peer Discovery Signal . . . . . . . . . . . . . . . . . . 17 6.2. Peer Offer Signal . . . . . . . . . . . . . . . . . . . . 18
7.2. Peer Offer Signal . . . . . . . . . . . . . . . . . . . . 18 6.3. Peer Initialization Signal . . . . . . . . . . . . . . . 18
7.3. Peer Initialization Signal . . . . . . . . . . . . . . . 19 6.4. Peer Initialization ACK Signal . . . . . . . . . . . . . 19
7.4. Peer Initialization ACK Signal . . . . . . . . . . . . . 20 6.5. Peer Update Signal . . . . . . . . . . . . . . . . . . . 21
7.5. Peer Update Signal . . . . . . . . . . . . . . . . . . . 21 6.6. Peer Update ACK Signal . . . . . . . . . . . . . . . . . 22
7.6. Peer Update ACK Signal . . . . . . . . . . . . . . . . . 22 6.7. Peer Termination Signal . . . . . . . . . . . . . . . . . 23
7.7. Peer Termination Signal . . . . . . . . . . . . . . . . . 23 6.8. Peer Termination ACK Signal . . . . . . . . . . . . . . . 24
7.8. Peer Termination ACK Signal . . . . . . . . . . . . . . . 23 6.9. Destination Up Signal . . . . . . . . . . . . . . . . . . 24
7.9. Destination Up Signal . . . . . . . . . . . . . . . . . . 24 6.10. Destination Up ACK Signal . . . . . . . . . . . . . . . . 25
7.10. Destination Up ACK Signal . . . . . . . . . . . . . . . . 25 6.11. Destination Down Signal . . . . . . . . . . . . . . . . . 26
7.11. Destination Down Signal . . . . . . . . . . . . . . . . . 26 6.12. Destination Down ACK Signal . . . . . . . . . . . . . . . 26
7.12. Destination Down ACK Signal . . . . . . . . . . . . . . . 26 6.13. Destination Update Signal . . . . . . . . . . . . . . . . 27
7.13. Destination Update Signal . . . . . . . . . . . . . . . . 26 6.14. Heartbeat Signal . . . . . . . . . . . . . . . . . . . . 28
7.14. Heartbeat Signal . . . . . . . . . . . . . . . . . . . . 28 6.15. Link Characteristics Request Signal . . . . . . . . . . . 28
7.15. Link Characteristics Request Signal . . . . . . . . . . . 28 6.16. Link Characteristics ACK Signal . . . . . . . . . . . . . 29
7.16. Link Characteristics ACK Signal . . . . . . . . . . . . . 29 7. DLEP Data Items . . . . . . . . . . . . . . . . . . . . . . . 30
8. DLEP Data Items . . . . . . . . . . . . . . . . . . . . . . . 30 7.1. DLEP Version . . . . . . . . . . . . . . . . . . . . . . 31
8.1. DLEP Version . . . . . . . . . . . . . . . . . . . . . . 31 7.2. Status . . . . . . . . . . . . . . . . . . . . . . . . . 32
8.2. Status . . . . . . . . . . . . . . . . . . . . . . . . . 32 7.3. IPv4 Connection Point . . . . . . . . . . . . . . . . . . 33
8.3. DLEP Port . . . . . . . . . . . . . . . . . . . . . . . . 33 7.4. IPv6 Connection Point . . . . . . . . . . . . . . . . . . 34
8.4. Peer Type . . . . . . . . . . . . . . . . . . . . . . . . 33 7.5. Peer Type . . . . . . . . . . . . . . . . . . . . . . . . 35
8.5. Heartbeat Interval . . . . . . . . . . . . . . . . . . . 34 7.6. Heartbeat Interval . . . . . . . . . . . . . . . . . . . 35
8.6. Extensions Supported . . . . . . . . . . . . . . . . . . 35 7.7. Extensions Supported . . . . . . . . . . . . . . . . . . 36
8.7. Experimental Definition . . . . . . . . . . . . . . . . . 35 7.8. Experimental Definition . . . . . . . . . . . . . . . . . 36
8.8. MAC Address . . . . . . . . . . . . . . . . . . . . . . . 36 7.9. MAC Address . . . . . . . . . . . . . . . . . . . . . . . 37
8.9. IPv4 Address . . . . . . . . . . . . . . . . . . . . . . 37 7.10. IPv4 Address . . . . . . . . . . . . . . . . . . . . . . 38
8.10. IPv6 Address . . . . . . . . . . . . . . . . . . . . . . 37 7.11. IPv6 Address . . . . . . . . . . . . . . . . . . . . . . 38
8.11. IPv4 Attached Subnet . . . . . . . . . . . . . . . . . . 38 7.12. IPv4 Attached Subnet . . . . . . . . . . . . . . . . . . 39
8.12. IPv6 Attached Subnet . . . . . . . . . . . . . . . . . . 39 7.13. IPv6 Attached Subnet . . . . . . . . . . . . . . . . . . 40
8.13. Maximum Data Rate (Receive) . . . . . . . . . . . . . . . 39 7.14. Maximum Data Rate (Receive) . . . . . . . . . . . . . . . 40
8.14. Maximum Data Rate (Transmit) . . . . . . . . . . . . . . 40 7.15. Maximum Data Rate (Transmit) . . . . . . . . . . . . . . 41
8.15. Current Data Rate (Receive) . . . . . . . . . . . . . . . 41 7.16. Current Data Rate (Receive) . . . . . . . . . . . . . . . 42
8.16. Current Data Rate (Transmit) . . . . . . . . . . . . . . 41 7.17. Current Data Rate (Transmit) . . . . . . . . . . . . . . 42
8.17. Latency . . . . . . . . . . . . . . . . . . . . . . . . . 42 7.18. Latency . . . . . . . . . . . . . . . . . . . . . . . . . 43
8.18. Resources (Receive) . . . . . . . . . . . . . . . . . . . 43 7.19. Resources (Receive) . . . . . . . . . . . . . . . . . . . 44
8.19. Resources (Transmit) . . . . . . . . . . . . . . . . . . 43 7.20. Resources (Transmit) . . . . . . . . . . . . . . . . . . 45
8.20. Relative Link Quality (Receive) . . . . . . . . . . . . . 44 7.21. Relative Link Quality (Receive) . . . . . . . . . . . . . 45
8.21. Relative Link Quality (Transmit) . . . . . . . . . . . . 45 7.22. Relative Link Quality (Transmit) . . . . . . . . . . . . 46
8.22. Link Characteristics ACK Timer . . . . . . . . . . . . . 45 7.23. Link Characteristics ACK Timer . . . . . . . . . . . . . 46
9. Credit-Windowing . . . . . . . . . . . . . . . . . . . . . . 46 8. Credit-Windowing . . . . . . . . . . . . . . . . . . . . . . 47
9.1. Credit-Windowing Signals . . . . . . . . . . . . . . . . 46 8.1. Credit-Windowing Signals . . . . . . . . . . . . . . . . 47
9.1.1. Destination Up Signal . . . . . . . . . . . . . . . . 46 8.1.1. Destination Up Signal . . . . . . . . . . . . . . . . 48
9.1.2. Destination Up ACK Signal . . . . . . . . . . . . . . 47 8.1.2. Destination Up ACK Signal . . . . . . . . . . . . . . 48
9.1.3. Destination Update Signal . . . . . . . . . . . . . . 47 8.1.3. Destination Update Signal . . . . . . . . . . . . . . 48
9.2. Credit-Windowing Data Items . . . . . . . . . . . . . . . 47 8.2. Credit-Windowing Data Items . . . . . . . . . . . . . . . 48
9.2.1. Credit Window Status . . . . . . . . . . . . . . . . 47 8.2.1. Credit Grant . . . . . . . . . . . . . . . . . . . . 49
9.2.2. Credit Grant . . . . . . . . . . . . . . . . . . . . 48 8.2.2. Credit Window Status . . . . . . . . . . . . . . . . 50
9.2.3. Credit Request . . . . . . . . . . . . . . . . . . . 49 8.2.3. Credit Request . . . . . . . . . . . . . . . . . . . 50
10. Security Considerations . . . . . . . . . . . . . . . . . . . 50 9. Security Considerations . . . . . . . . . . . . . . . . . . . 51
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 50 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 51
11.1. Registrations . . . . . . . . . . . . . . . . . . . . . 50 10.1. Registrations . . . . . . . . . . . . . . . . . . . . . 51
11.2. Expert Review: Evaluation Guidelines . . . . . . . . . . 51 10.2. Expert Review: Evaluation Guidelines . . . . . . . . . . 52
11.3. Signal Type Registration . . . . . . . . . . . . . . . . 51 10.3. Signal Type Registration . . . . . . . . . . . . . . . . 52
11.4. DLEP Data Item Registrations . . . . . . . . . . . . . . 52 10.4. DLEP Data Item Registrations . . . . . . . . . . . . . . 53
11.5. DLEP Status Code Registrations . . . . . . . . . . . . . 53 10.5. DLEP Status Code Registrations . . . . . . . . . . . . . 54
11.6. DLEP Extensions Registrations . . . . . . . . . . . . . 53 10.6. DLEP Extensions Registrations . . . . . . . . . . . . . 54
11.7. DLEP Well-known Port . . . . . . . . . . . . . . . . . . 54 10.7. DLEP Well-known Port . . . . . . . . . . . . . . . . . . 55
11.8. DLEP Multicast Address . . . . . . . . . . . . . . . . . 54 10.8. DLEP Multicast Address . . . . . . . . . . . . . . . . . 55
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 54 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 55
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 54 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 55
13.1. Normative References . . . . . . . . . . . . . . . . . . 54 12.1. Normative References . . . . . . . . . . . . . . . . . . 55
13.2. Informative References . . . . . . . . . . . . . . . . . 54 12.2. Informative References . . . . . . . . . . . . . . . . . 55
Appendix A. Peer Level Signal Flows . . . . . . . . . . . . . . 54 Appendix A. Peer Level Signal Flows . . . . . . . . . . . . . . 55
A.1. Router Device Restarts Discovery . . . . . . . . . . . . 54 A.1. Discovery . . . . . . . . . . . . . . . . . . . . . . . . 55
A.2. Router Device Detects Peer Offer Timeout . . . . . . . . 55 A.2. Session Initialization . . . . . . . . . . . . . . . . . 56
A.3. Router Peer Offer Lost . . . . . . . . . . . . . . . . . 55 A.3. Session Initialization - Refused . . . . . . . . . . . . 57
A.4. Discovery Success . . . . . . . . . . . . . . . . . . . . 56 A.4. Router Changes IP Addresses . . . . . . . . . . . . . . . 57
A.5. Router Detects a Heartbeat timeout . . . . . . . . . . . 57 A.5. Modem Changes Session-wide Metrics . . . . . . . . . . . 57
A.6. Modem Detects a Heartbeat timeout . . . . . . . . . . . . 57 A.6. Router Terminates Session . . . . . . . . . . . . . . . . 58
A.7. Peer Terminate (from Modem) Lost . . . . . . . . . . . . 58 A.7. Modem Terminates Session . . . . . . . . . . . . . . . . 58
A.8. Peer Terminate (from Router) Lost . . . . . . . . . . . . 58 A.8. Session Heartbeats . . . . . . . . . . . . . . . . . . . 59
Appendix B. Destination Specific Signal Flows . . . . . . . . . 59 A.9. Router Detects a Heartbeat timeout . . . . . . . . . . . 60
B.1. Modem Destination Up Lost . . . . . . . . . . . . . . . . 59 A.10. Modem Detects a Heartbeat timeout . . . . . . . . . . . . 61
B.2. Router Detects Duplicate Destination Ups . . . . . . . . 59 Appendix B. Destination Specific Signal Flows . . . . . . . . . 61
B.3. Destination Up, No Layer 3 Addresses . . . . . . . . . . 60 B.1. Common Destination Signaling . . . . . . . . . . . . . . 61
B.4. Destination Up with IPv4, No IPv6 . . . . . . . . . . . . 60 B.2. Multicast Destination Signaling . . . . . . . . . . . . . 62
B.5. Destination Up with IPv4 and IPv6 . . . . . . . . . . . . 61 B.3. Link Characteristics Request . . . . . . . . . . . . . . 62
B.6. Destination Session Success . . . . . . . . . . . . . . . 61 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 63
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 62
1. Introduction 1. Introduction
There exist today a collection of modem devices that control links of There exist today a collection of modem devices that control links of
variable datarate and quality. Examples of these types of links variable datarate and quality. Examples of these types of links
include line-of-sight (LOS) terrestrial radios, satellite terminals, include line-of-sight (LOS) terrestrial radios, satellite terminals,
and cable/DSL modems. Fluctuations in speed and quality of these and cable/DSL modems. Fluctuations in speed and quality of these
links can occur due to configuration (in the case of cable/DSL links can occur due to configuration (in the case of cable/DSL
modems), or on a moment-to-moment basis, due to physical phenomena modems), or on a moment-to-moment basis, due to physical phenomena
like multipath interference, obstructions, rain fade, etc. It is like multipath interference, obstructions, rain fade, etc. It is
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difficult to establish and properly maintain. This is especially difficult to establish and properly maintain. This is especially
true of demand-based access schemes such as Demand Assigned Multiple true of demand-based access schemes such as Demand Assigned Multiple
Access (DAMA) implementations used on some satellite systems. With a Access (DAMA) implementations used on some satellite systems. With a
DAMA-based system, additional datarate may be available, but will not DAMA-based system, additional datarate may be available, but will not
be used unless the network devices emit traffic at a rate higher than be used unless the network devices emit traffic at a rate higher than
the currently established rate. Increasing the traffic rate does not the currently established rate. Increasing the traffic rate does not
guarantee additional datarate will be allocated; rather, it may guarantee additional datarate will be allocated; rather, it may
result in data loss and additional retransmissions on the link. result in data loss and additional retransmissions on the link.
Addressing the challenges listed above, the authors have developed Addressing the challenges listed above, the authors have developed
the Data Link Exchange Protocol, or DLEP. The DLEP protocol runs the Dynamic Link Exchange Protocol, or DLEP. The DLEP protocol runs
between a router and its attached modem devices, allowing the modem between a router and its attached modem devices, allowing the modem
to communicate link characteristics as they change, and convergence to communicate link characteristics as they change, and convergence
events (acquisition and loss of potential routing destinations). The events (acquisition and loss of potential routing destinations). The
following diagrams are used to illustrate the scope of DLEP packets. following diagrams are used to illustrate the scope of DLEP packets.
|-------Local Node-------| |-------Remote Node------| |-------Local Node-------| |-------Remote Node------|
| | | | | | | |
+--------+ +-------+ +-------+ +--------+ +--------+ +-------+ +-------+ +--------+
| Router |=======| Modem |{~~~~~~~~}| Modem |=======| Router | | Router |=======| Modem |{~~~~~~~~}| Modem |=======| Router |
| | | Device| | Device| | | | | | Device| | Device| | |
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| | | 802.11) | | | | | | 802.11) | | |
Figure 1: DLEP Network Figure 1: DLEP Network
In Figure 1, when the local modem detects the presence of a remote In Figure 1, when the local modem detects the presence of a remote
node, it (the local modem) sends a signal to its router via the DLEP node, it (the local modem) sends a signal to its router via the DLEP
protocol. Upon receipt of the signal, the local router may take protocol. Upon receipt of the signal, the local router may take
whatever action it deems appropriate, such as initiating discovery whatever action it deems appropriate, such as initiating discovery
protocols, and/or issuing HELLO messages to converge the network. On protocols, and/or issuing HELLO messages to converge the network. On
a continuing, as-needed basis, the modem devices utilize DLEP to a continuing, as-needed basis, the modem devices utilize DLEP to
report any characteristics of the link (datarate, latency, etc) that report any characteristics of the link (datarate, latency, etc.) that
have changed. DLEP is independent of the link type and topology have changed. DLEP is independent of the link type and topology
supported by the modem. Note that the DLEP protocol is specified to supported by the modem. Note that the DLEP protocol is specified to
run only on the local link between router and modem. Some over the run only on the local link between router and modem. Some over the
air signaling may be necessary between the local and remote modem in air signaling may be necessary between the local and remote modem in
order to provide some parameters in DLEP signals between the local order to provide some parameters in DLEP signals between the local
modem and local router, but DLEP does not specify how such over the modem and local router, but DLEP does not specify how such over the
air signaling is carried out. Over the air signaling is purely a air signaling is carried out. Over the air signaling is purely a
matter for the modem implementer. matter for the modem implementer.
Figure 2 shows how DLEP can support a configuration where routers are Figure 2 shows how DLEP can support a configuration where routers are
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+---+----+ +---+----+
| |
| |
+---+----+ +---+----+
| Router | | Router |
| | | |
+--------+ +--------+
Figure 2: DLEP Network with Multiple Modem Devices Figure 2: DLEP Network with Multiple Modem Devices
1.1. Protocol Overview
DLEP defines a set of signals used by modems and their attached DLEP defines a set of signals used by modems and their attached
routers. The signals are used to communicate events that occur on routers. The signals are used to communicate events that occur on
the physical link(s) managed by the modem: for example, a remote node the physical link(s) managed by the modem: for example, a remote node
entering or leaving the network, or that the link has changed. entering or leaving the network, or that the link has changed.
Associated with these signals are a set of data items - information Associated with these signals are a set of data items - information
that describes the remote node (e.g., address information), and/or that describes the remote node (e.g., address information), and/or
the characteristics of the link to the remote node. the characteristics of the link to the remote node.
The protocol is defined as a collection of type-length-value (TLV) The protocol is defined as a collection of type-length-value (TLV)
based formats, specifying the signals that are exchanged between a based formats, specifying the signals that are exchanged between a
router and a modem, and the data items associated with the signal. router and a modem, and the data items associated with the signal.
This document specifies transport of DLEP signals and data items via This document specifies transport of DLEP signals and data items via
the TCP transport, with a UDP-based discovery mechanism. Other the TCP transport, with a UDP-based discovery mechanism. Other
transports for the protocol are possible, but are outside the scope transports for the protocol are possible, but are outside the scope
of this document. of this document.
DLEP uses a session-oriented paradigm between the modem device and DLEP uses a session-oriented paradigm between the modem device and
its associated router. If multiple modem devices are attached to a its associated router. If multiple modem devices are attached to a
router (as in Figure 2), a separate DLEP session MUST exist for each router (as in Figure 2), or the modem supports multiple connections
modem. If a modem device supports multiple connections to a router (via multiple logical or physical interfaces), then separate DLEP
(via multiple logical or physical interfaces), or supports sessions exist for each modem or connection. This router/modem
connections to multiple routers, a separate DLEP session MUST exist session provides a carrier for information exchange concerning
for each connection. This router/modem session provides a carrier 'destinations' that are available via the modem device. A
for information exchange concerning 'destinations' that are available 'destination' can be either physical (as in the case of a specific
via the modem device. A 'destination' can be either physical (as in far-end router), or a logical destination (as in a Multicast group).
the case of a specific far-end router), or a logical destination (as As such, all of the destination-level exchanges in DLEP can be
in a Multicast group). As such, all of the destination-level envisioned as building an information base concerning the remote
exchanges in DLEP can be envisioned as building an information base nodes, and the link characteristics to those nodes.
concerning the remote nodes, and the link characteristics to those
nodes.
Any DLEP signal that is NOT understood by a receiver MUST result in
an error indication being sent to the originator, and also MUST
result in termination of the session between the DLEP peers. Any
data item that is NOT understood by a receiver MUST be ignored.
Multicast traffic destined for the variable-quality network (the Multicast traffic destined for the variable-quality network (the
network accessed via the DLEP modem) is handled in IP networks by network accessed via the DLEP modem) is handled in IP networks by
deriving a Layer 2 MAC address based on the Layer 3 address. deriving a Layer 2 MAC address based on the Layer 3 address.
Leveraging on this scheme, Multicast traffic is supported in DLEP Leveraging on this scheme, multicast traffic is supported in DLEP
simply by treating the derived MAC address as any other 'destination' simply by treating the derived MAC address as any other 'destination'
(albeit a logical one) in the network. To support these logical (albeit a logical one) in the network. To support these logical
destinations, one of the DLEP participants (typically, the router) destinations, one of the DLEP participants (typically, the router)
informs the other as to the existence of the logical neighbor. The informs the other as to the existence of the logical destination.
modem, once it is aware of the existence of this logical neighbor, The modem, once it is aware of the existence of this logical
reports link characteristics just as it would for any other destination, reports link characteristics just as it would for any
destination in the network. The specific algorithms a modem would other destination in the network. The specific algorithms a modem
use to report metrics on multicast (or logical) destinations is would use to derive metrics on multicast (or logical) destinations is
outside the scope of this specification, and is left to specific outside the scope of this specification, and is left to specific
implementations to decide. implementations to decide.
1.1. Requirements 1.2. Requirements
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in BCP 14, RFC 2119 document are to be interpreted as described in BCP 14, RFC 2119
[RFC2119]. [RFC2119].
2. Assumptions 2. Assumptions
Routers and modems that exist as part of the same node (e.g., that Routers and modems that exist as part of the same node (e.g., that
are locally connected) can utilize a discovery technique to locate are locally connected) can utilize a discovery technique to locate
each other, thus avoiding a-priori configuration. The router is each other, thus avoiding a-priori configuration. The router is
responsible for initializing the discovery process, using the Peer responsible for initializing the discovery process, using the Peer
Discovery signal (Section 7.1). Discovery signal (Section 6.1).
DLEP utilizes a session-oriented paradigm. A router and modem form a DLEP utilizes a session-oriented paradigm. A router and modem form a
session by completing the discovery process. This router-modem session by completing the discovery and initialization process. This
session persists unless or until it either (1) times out, based on router-modem session persists unless or until it either (1) times
the timeout values supplied, or (2) is explicitly torn down by one of out, based on the timeout values supplied, or (2) is explicitly torn
the participants. Note that while use of timers in DLEP is OPTIONAL, down by one of the participants. Note that while use of timers in
it is strongly recommended that implementations choose to run with DLEP is OPTIONAL, it is strongly recommended that implementations
timers enabled. choose to run with timers enabled.
DLEP assumes that the MAC address for delivering data traffic is the DLEP assumes that the MAC address for delivering data traffic is the
MAC specified in the Destination Up signal (Section 7.9). No MAC specified in the Destination Up signal (Section 6.9). No
manipulation or or substitution is performed; the MAC address manipulation or substitution is performed; the MAC address supplied
supplied in Destination Up is used as the OSI Layer 2 Destination MAC in Destination Up is used as the OSI Layer 2 Destination MAC address.
address. DLEP also assumes that MAC addresses MUST be unique within DLEP also assumes that MAC addresses MUST be unique within the
the context of a router-modem session. context of a router-modem session.
DLEP utilizes UDP multicast for single-hop discovery, and TCP for DLEP utilizes UDP multicast for single-hop discovery, and TCP for
transport of the control signals. Therefore, DLEP assumes that the transport of the control signals. Therefore, DLEP assumes that the
modem and router have topologically consistent IP addresses assigned. modem and router have topologically consistent IP addresses assigned.
It is recommended that DLEP implementations utilize IPv6 link-local It is recommended that DLEP implementations utilize IPv6 link-local
addresses to reduce the administrative burden of address assignment. addresses to reduce the administrative burden of address assignment.
This document refers to a remote node as a 'Destination'.
Destinations can be identified by either the router or the modem, and Destinations can be identified by either the router or the modem, and
represent a specific destination (e.g., an address) that exists on represent a specific destination (e.g., an address) that exists on
the link(s) managed by the modem. A destination MUST contain a MAC the link(s) managed by the modem. A destination MUST contain a MAC
address, it MAY optionally include a Layer 3 address (or addresses). address, it MAY optionally include a Layer 3 address (or addresses).
Note that since a destination is a MAC address, the MAC could Note that since a destination is a MAC address, the MAC could
reference a logical destination, as in a derived multicast MAC reference a logical destination, as in a derived multicast MAC
address, as well as to a physical device. As destinations are address, as well as a physical device. As destinations are
discovered, DLEP routers and modems build an information base on discovered, DLEP routers and modems build an information base on
destinations accessible via the modem. Changes in link destinations accessible via the modem.
characteristics are then reported as being 'modem-wide' (effecting
ALL destinations accessed via the modem, reported via the Peer Update
signal, Section 7.5) or reported for a specific neighbor (via the
Destination Update signal, Section 7.13).
The DLEP signals concerning destinations thus become the way for The DLEP signals concerning destinations thus become the way for
routers and modems to maintain, and notify each other about, an routers and modems to maintain, and notify each other about, an
information base representing the physical and logical (e.g., information base representing the physical and logical (e.g.,
multicast) destinations accessible via the modem device. The multicast) destinations accessible via the modem device. The
information base would contain addressing information (i.e., MAC information base would contain addressing information (i.e. MAC
address, and OPTIONALLY, Layer 3 addresses), link characteristics address, and OPTIONALLY, Layer 3 addresses), link characteristics
(metrics), and OPTIONALLY, flow control information (credits). (metrics), and OPTIONALLY, flow control information (credits).
DLEP assumes that any signal not understood by a receiver MUST result
in an error indication being sent to the originator, and also MUST
result in termination of the session between the DLEP peers. Any
data item that is not understood by a receiver MUST be ignored.
DLEP assumes that security on the session (e.g., authentication of DLEP assumes that security on the session (e.g., authentication of
session partners, encryption of traffic, or both) is dealt with by session partners, encryption of traffic, or both) is dealt with by
the underlying transport mechanism (e.g., by using a transport such the underlying transport mechanism (e.g., by using a transport such
as TLS [RFC5246]). as TLS [RFC5246]).
This document specifies an implementation of the DLEP signals and This document specifies an implementation of the DLEP signals and
data items running over the TCP transport. It is assumed that DLEP data items running over the TCP transport. It is assumed that DLEP
running over other transport mechanisms would be documented running over other transport mechanisms would be documented
separately. separately.
skipping to change at page 10, line 27 skipping to change at page 10, line 22
core signals and data items might not be used during the lifetime of core signals and data items might not be used during the lifetime of
a single DLEP session, but a compliant implementation MUST support a single DLEP session, but a compliant implementation MUST support
them. them.
While this document represents the best efforts of the co-authors, While this document represents the best efforts of the co-authors,
and the working group, to be functionally complete, it is recognized and the working group, to be functionally complete, it is recognized
that extensions to DLEP will in all likelihood be necessary as more that extensions to DLEP will in all likelihood be necessary as more
link types are utilized. To support future extension of DLEP, this link types are utilized. To support future extension of DLEP, this
document describes an extension negotiation capability to be used document describes an extension negotiation capability to be used
during session initialization via the Extensions Supported data item, during session initialization via the Extensions Supported data item,
documented in Section 8.6 of this document. documented in Section 7.7 of this document.
All extensions are considered OPTIONAL. Only the DLEP functionality All extensions are considered OPTIONAL. Only the DLEP functionality
listed as 'mandatory' is required by implementation in order to be listed as 'mandatory' is required by implementation in order to be
DLEP compliant. DLEP compliant.
This specification defines one extension, Credit processing, exposed This specification defines one extension, Credit windowing, exposed
via the Extensions Supported mechanism that implementations MAY chose via the Extensions Supported mechanism that implementations MAY
to implement, or to omit. choose to implement, or to omit.
3.1. Negotiation of Optional Extensions 3.1. Negotiation of Optional Extensions
Optional extensions supported by an implementation MUST be declared Optional extensions supported by an implementation MUST be declared
to potential DLEP peers using the Extensions Supported data item to potential DLEP peers using the Extensions Supported data item
(Section 8.6) during the session initialization sequence. Once both (Section 7.7) during the session initialization sequence. Once both
peers have exchanged initialization signals, an implementation MUST peers have exchanged initialization signals, an implementation MUST
NOT emit any signal or data item associated with an optional NOT emit any signal or data item associated with an optional
extension that was not specified in the received initialization extension that was not specified in the received initialization
signal from its peer. signal from its peer.
3.2. Protocol Extensions 3.2. Protocol Extensions
If/when protocol extensions are required, they should be standardized If/when protocol extensions are required, they should be standardized
either as an update to this document, or as an additional stand-alone either as an update to this document, or as an additional stand-alone
specification. The requests for IANA-controlled registries in this specification. The requests for IANA-controlled registries in this
document contain sufficient reserved space, both in terms of DLEP document contain sufficient reserved space, both in terms of DLEP
signals and DLEP data items, to accomodate future extensions to the signals and DLEP data items, to accommodate future extensions to the
protocol and the data transferred. protocol and the data transferred.
3.3. Experimental Signals and Data Items 3.3. Experimental Signals and Data Items
This document requests numbering space in both the DLEP signal and This document requests numbering space in both the DLEP signal and
data item registries for experimental items. The intent is to allow data item registries for experimental items. The intent is to allow
for experimentation with new signals and/or data items, while still for experimentation with new signals and/or data items, while still
retaining the documented DLEP behavior. If a given experiment proves retaining the documented DLEP behavior. If a given experiment proves
successful, it SHOULD be documented as an update to this document, or successful, it SHOULD be documented as an update to this document, or
as a stand-alone specification. as a stand-alone specification.
Use of the experimental signals or data items MUST be announced by Use of the experimental signals, data items, or behaviors MUST be
inclusion of an Experimental Definition data item (Section 8.7) with announced by inclusion of an Experimental Definition data item
a value agreed upon (a-priori) between the participating peers. The (Section 7.8) with a value agreed upon (a-priori) between the
exact mechanism for a-priori communication of the experimental participating peers. The exact mechanism for a-priori communication
definition formats is beyond the scope of this document. of the experimental definition formats is beyond the scope of this
document.
Multiple Experimental Definition data items MAY appear in the Peer Multiple Experimental Definition data items MAY appear in the Peer
Initialization/Peer Initialization ACK sequence. However, use of Initialization/Peer Initialization ACK sequence. However, use of
multiple experiments in a single peer session could lead to multiple experiments in a single peer session could lead to
interoperability issues or unexpected results (e.g., redefinition of interoperability issues or unexpected results (e.g., redefinition of
experimental signals and/or data items), and is therefore experimental signals and/or data items), and is therefore
discouraged. It is left to implementations to determine the correct discouraged. It is left to implementations to determine the correct
processing path (e.g., a decision on whether to terminate the peer processing path (e.g., a decision on whether to terminate the peer
session, or to establish a precedence of the conflicting definitions) session, or to establish a precedence of the conflicting definitions)
if such conflicts arise. if such conflicts arise.
4. Metrics 4. Metrics
DLEP includes the ability for the router and modem to communicate DLEP includes the ability for the router and modem to communicate
metrics that reflect the characteristics (e.g., datarate, latency) of metrics that reflect the characteristics (e.g., datarate, latency) of
the variable-quality link in use. DLEP does NOT specify how a given the variable-quality link in use. DLEP does NOT specify how a given
metric value is to be calculated, rather, the protocol assumes that metric value is to be calculated, rather, the protocol assumes that
metrics have been calculated with a 'best effort', incorporating all metrics have been calculated with a 'best effort', incorporating all
pertinent data that is available to the modem device. pertinent data that is available to the modem device.
As mentioned in the introduction section of this document, metrics As mentioned in the introduction section of this document, DLEP
have to be used within a context - for example, metrics to a unicast allows for metrics to be sent within two contexts - metrics for a
address in the network. DLEP allows for metrics to be sent within specific destination within the network (e.g., a specific router),
two contexts - metrics for a specific destination within the network and 'modem-wide' (those that apply to all destinations accessed via
(e.g., a specific router), and 'modem-wide' (those that apply to all the modem). Most metrics can be further subdivided into transmit and
destinations accessed via the modem). Metrics can be further receive metrics. Metrics supplied on DLEP Peer signals are, by
subdivided into transmit and receive metrics. Metrics supplied on definition, modem-wide; metrics supplied on Destination signals are,
DLEP Peer signals are, by definition, modem-wide; metrics supplied on by definition, used for the specific logical destination only.
Destination signals are, by definition, used for the specific
neighbor only.
DLEP modem implementations MUST announce all supported metric items, DLEP modem implementations MUST announce all supported metric items,
and provide default values for those metrics, in the Peer and provide default values for those metrics, in the Peer
Initialization signal (Section 7.3). In order to introduce a new Initialization ACK signal (Section 6.4). In order to introduce a new
metric type, DLEP modem implementations MUST terminate the session metric type, DLEP modem implementations MUST terminate the session
with the router (via the Peer Terminate signal, Section 7.7), and re- with the router (via the Peer Terminate signal (Section 6.7)), and
establish the session. re-establish the session.
It is left to implementations to choose sensible default values based It is left to implementations to choose sensible default values based
on their specific characteristics. Modems having static (non- on their specific characteristics. Modems having static (non-
changing) link metric characteristics MAY report metrics only once changing) link metric characteristics MAY report metrics only once
for a given neighbor (or once on a modem-wide basis, if all for a given destination (or once on a modem-wide basis, if all
connections via the modem are of this static nature). connections via the modem are of this static nature).
The approach of allowing for different contexts for metric data The approach of allowing for different contexts for metric data
increases both the flexibility and the complexity of using metric increases both the flexibility and the complexity of using metric
data. This document details the mechanism whereby the data is data. This document details the mechanism whereby the data is
transmitted, however, the specific algorithms (precedence, etc) for transmitted, however, the specific algorithms (precedence, etc.) for
utilizing the dual-context metrics is out of scope and not addressed utilizing the dual-context metrics is out of scope and not addressed
by this document. by this document.
4.1. Mandatory Metrics 4.1. Mandatory Metrics
As mentioned above, DLEP modem implementations MUST announce all As mentioned above, DLEP modem implementations MUST announce all
supported metric items during session initialization. However, an supported metric items during session initialization. However, an
implementation MUST include the following list of metrics: implementation MUST include the following list of metrics:
o Maximum Data Rate (Receive) (Section 8.13) o Maximum Data Rate (Receive) (Section 7.14)
o Maximum Data Rate (Transmit) (Section 8.14)
o Current Data Rate (Receive) (Section 8.15)
o Current Data Rate (Transmit) (Section 8.16) o Maximum Data Rate (Transmit) (Section 7.15)
o Latency (Section 8.17) o Current Data Rate (Receive) (Section 7.16)
5. Normal Session Flow o Current Data Rate (Transmit) (Section 7.17)
Normal session flow for a DLEP router has two sub-cases, depending on o Latency (Section 7.18)
whether the implementation supports the discovery process. Modem
implementations MUST support the Discovery case; router
implementations MAY support discovery, or rely on a-priori
configuration to define the address(es) of attached modems.
5.1. DLEP Router session flow - Discovery case 4.2. DLEP Router session flow - Discovery case
If the DLEP router implementation is utilizing the optional discovery If the DLEP router implementation is utilizing the optional discovery
mechanism, then the implementation will initialize a UDP socket, mechanism, then the implementation will initialize a UDP socket,
binding it to an arbitrary port. This UDP socket is used to send the binding it to an arbitrary port. This UDP socket is used to send the
Peer Discovery signal (Section 7.1) to the DLEP link-local multicast Peer Discovery signal (Section 6.1) to the DLEP link-local multicast
address and port (TBD). The implementation then waits on receipt of address and port (TBD). The implementation then waits on receipt of
a Peer Offer signal (Section 7.2), which MUST contain the unicast a Peer Offer signal (Section 6.2), which MAY contain the unicast
address and port for TCP-based communication with a DLEP modem. The address and port for TCP-based communication with a DLEP modem, via
Peer Offer signal MAY contain multiple address/port combinations. If the IPv4 Connection Point data item (Section 7.3) or the IPv6
more than one address/port combination is in the Peer Offer, the DLEP Connection Point data item (Section 7.4). The Peer Offer signal MAY
router implementation SHOULD consider the list to be in priority contain multiple IP Connection Point data items. If more than one IP
sequence, with the 'most desired' address/port combination listed Connection Point data items is in the Peer Offer, router
first. However, router implementations MAY use their own heuristics implementations MAY use their own heuristics to determine the best
to determine the best address/port combination. At this point, the address/port combination. If no IP Connection Point data items are
router implementation MAY either destroy the UDP socket, or continue included in the Peer Offer signal, the receiver MUST use the origin
to issue Peer Discovery signals to the link-local address/port address of the signal as the IP address, and the DLEP well-known port
combination. In either case, the TCP session initialization occurs number (Section 10.7) to establish the TCP connection. At this
as in the configured case. point, the router implementation MAY either destroy the UDP socket,
or continue to issue Peer Discovery signals to the link-local
address/port combination. In either case, the TCP session
initialization occurs as in the configured case.
5.2. DLEP Router session flow - Configured case 4.3. DLEP Router session flow - Configured case
When a DLEP router implementation has the address and port When a DLEP router implementation has the address and port
information for a TCP connection to a modem (obtained either via information for a TCP connection to a modem (obtained either via
configuration or via the discovery process described above), the configuration or via the discovery process described above), the
router will initialize and bind a TCP socket. This socket is used to router will initialize and bind a TCP socket. This socket is used to
connect to the DLEP modem software. After a successful TCP connect, connect to the DLEP modem software. After a successful TCP connect,
the modem implementation MUST issue a Peer Initialization signal the router implementation MUST issue a Peer Initialization signal
(Section 7.3) to the DLEP router. The Peer Initialization signal (Section 6.3) to the DLEP modem. After sending the Peer
MUST contain data items for ALL supported metrics from this modem, Initialization, the router implementation MUST wait for receipt of a
along with the default values of those metrics. After sending the Peer Initialization ACK signal (Section 6.4) from the modem. Receipt
Peer Initialization, the modem implementation MUST wait for receipt of the Peer Initialization ACK signal containing a Status data item
of a Peer Initialization ACK signal (Section 7.4) from the router. (Section 7.2) with value 'Success', indicates that the modem has
Receipt of the Peer Initialization ACK signal indicates that the received and processed the Peer Initialization, and the session MUST
router has received and processed the Peer Initialization, and the transition to the 'in session' state. At this point, signals
session MUST transition to the 'in session' state. At this point, regarding destinations in the network, and/or Peer Update signals
signals regarding destinations in the network, and/or Peer Update (Section 6.5), can flow on the DLEP session between modem and router,
signals (Section 7.5), can flow on the DLEP session between modem and and Heartbeat signals can begin to flow, if Heartbeats are used. The
router. The 'in session' state is maintained until one of the 'in session' state is maintained until one of the following
following conditions occur: conditions occur:
o The session is explicitly terminated (using Peer Termination), or o The session is explicitly terminated (using Peer Termination), or
o The session times out, based on supplied timeout values. o The session times out, based on supplied timeout values.
5.3. DLEP Modem session flow 4.4. DLEP Modem session flow
DLEP modem implementations MUST support the discovery mechanism. DLEP modem implementations MUST support the discovery mechanism.
Therefore, the normal flow is as follows: Therefore, the normal flow is as follows:
The implementation will initialize a UDP socket, binding that socket The implementation will initialize a UDP socket, binding that socket
to the DLEP link-local multicast address (TBD) and the DLEP well- to the DLEP link-local multicast address (TBD) and the DLEP well-
known port number (also TBD). The implementation will then known port number (also TBD). The implementation will then
initialize a TCP socket, on a unicast address and port. This socket initialize a TCP socket, on a unicast address and port. This socket
is used to listen for incoming TCP connection requests. is used to listen for incoming TCP connection requests.
When the modem implementation receives a Peer Discovery signal When the modem implementation receives a Peer Discovery signal
(Section 7.1) on the UDP socket, it responds by issuing a Peer Offer (Section 6.1) on the UDP socket, it responds by issuing a Peer Offer
signal (Section 7.2) to the sender of the Peer Discovery signal. The signal (Section 6.2) to the sender of the Peer Discovery signal. The
Peer Offer signal MUST contain the unicast address and port of the Peer Offer signal MAY contain the unicast address and port of the
TCP listen socket, described above. A DLEP modem implementation MAY listening TCP socket, as described above. A DLEP modem
respond with ALL address/port combinations that have an active TCP implementation MAY respond with ALL address/port combinations that
listen posted. If multiple address/port combinations are listed, the have an active TCP listen posted. Anything other than Peer Discovery
receiver of the Peer Offer signal MAY connect on any available signals received on the UDP socket MUST be silently dropped.
address/port pair. Anything other than Peer Discovery signals
received on the UDP socket MUST be silently dropped.
When the DLEP modem implementation accepts a connection via TCP, it When the DLEP modem implementation accepts a connection via TCP, it
MUST send a Peer Initialization signal (Section 7.3). The Peer MUST wait for receipt of a Peer Initialization signal (Section 6.3),
Initialization signal MUST contain metric data items for ALL sent by the router. Upon receipt and successful parsing of a Peer
supported metrics. If an additional metric is to be introduced, the Initialization signal, the modem MUST respond with a Peer
DLEP session between router and modem MUST be terminated and Initialization ACK signal (Section 6.4). The Peer Initialization ACK
restarted, and the new metric described in a Peer Initialization signal MUST contain metric data items for ALL supported metrics. If
signal. an additional metric is to be introduced, the DLEP session between
router and modem MUST be terminated and restarted, and the new metric
described in a Peer Initialization ACK signal. Once the Peer
Initialization signal (Section 6.3) and Peer Initialization ACK
signal (Section 6.4) have been exchanged, the session is transitioned
to the 'in session' state. As in the router case, when the 'in
session' state is reached, signals regarding destinations in the
network, and/or Peer Update signals (Section 6.5), can flow on the
DLEP session between modem and router, and Heartbeat signals can
begin to flow, if Heartbeats are used. The 'in session' state
persists until the session is explicitly terminated (using Peer
Termination), or it times out (based on timeout values).
5.4. Common Session Flow 4.5. Common Session Flow
In order to maintain the session between router and modem, periodic In order to maintain the session between router and modem, periodic
Heartbeat signals (Section 7.14) MAY be exchanged. These signals are Heartbeat signals (Section 6.14) MAY be exchanged. These signals are
intended to keep the session alive, and to verify bidirectional intended to keep the session alive, and to verify bidirectional
connectivity between the two participants. DLEP also provides a Peer connectivity between the two participants. If [Heartbeat
Update signal (Section 7.5), intended to communicate some change in signals]#(sig_heartbeat) are exchanged, they do not begin until the
status (e.g., a change of layer 3 address parameters, or a modem-wide DLEP peer session has entered the 'in session' state. Each DLEP peer
link change). is responsible for the creation of Heartbeat signals (Section 6.14).
Receipt of any DLEP signal SHOULD reset the heartbeat interval timer
(e.g., valid DLEP signals take the place of, and obviate the need
for, Heartbeat signals).
DLEP also provides a Peer Update signal (Section 6.5), intended to
communicate some change in status (e.g., a change of layer 3 address
parameters, or a modem-wide link change).
In addition to the local (Peer level) signals above, the participants In addition to the local (Peer level) signals above, the participants
will transmit DLEP signals concerning destinations in the network. will transmit DLEP signals concerning destinations in the network.
These signals trigger creation/maintenance/deletion of destinations These signals trigger creation/maintenance/deletion of destinations
in the information base of the recipient. For example, a modem will in the information base of the recipient. For example, a modem will
inform its attached router of the presence of a new destination via inform its attached router of the presence of a new destination via
the Destination Up signal (Section 7.9). Receipt of a Destination Up the Destination Up signal (Section 6.9). Receipt of a Destination Up
causes the router to allocate the necessary resources, creating an causes the router to allocate the necessary resources, creating an
entry in the information base with the specifics (i.e., MAC Address, entry in the information base with the specifics (i.e. MAC Address,
Latency, Data Rate, etc) of the neighbor. The loss of a destination Latency, Data Rate, etc.) of the destination. The loss of a
is communicated via the Destination Down signal (Section 7.11), and destination is communicated via the Destination Down signal
changes in status to the destination (e.g., varying link quality, or (Section 6.11), and changes in status to the destination (e.g.,
addressing changes) are communicated via the Destination Update varying link quality, or addressing changes) are communicated via the
signal (Section 7.13). The information on a given neighbor will Destination Update signal (Section 6.13). The information on a given
persist in the router's information base until (1) a Destination Down destination will persist in the router's information base until (1) a
signal is received, indicating that the modem has lost contact with Destination Down signal is received, indicating that the modem has
the remote node, or (2) the router/modem session terminates, lost contact with the remote node, or (2) the router/modem session
indicating that the router has lost contact with its own local modem. terminates, indicating that the router has lost contact with its own
local modem.
Metrics can be expressed within the context of a specific neighbor Metrics can be expressed within the context of a specific destination
via the Destination Update signal, or on a modem-wide basis via the via the Destination Update signal, or on a modem-wide basis via the
Peer Update signal. In cases where metrics are provided on the Peer Update signal. In cases where metrics are provided at peer
router/modem session, the receiver MUST propagate the metrics to all level, the receiver MUST propagate the metrics to all destinations in
destinations in its information base that are accessed via the its information base that are accessed via the originator. A DLEP
originator. A DLEP participant MAY send metrics both in a router/ participant MAY send metrics both in a router/modem session context
modem session context (via the Peer Update signal) and a specific (via the Peer Update signal) and a specific destination context (via
neighbor context (via Destination Update) at any time. The Destination Update) at any time. The heuristics for applying
heuristics for applying received metrics is left to implementations. received metrics is left to implementations.
In addition to receiving metrics about the link, DLEP provides a In addition to receiving metrics about the link, DLEP provides a
signal allowing a router to request a different datarate, or latency, signal allowing a router to request a different datarate, or latency,
from the modem. This signal is referred to as the Link from the modem. This signal is referred to as the Link
Characteristics Request signal (Section 7.15), and gives the router Characteristics Request signal (Section 6.15), and gives the router
the ability to deal with requisite increases (or decreases) of the ability to deal with requisite increases (or decreases) of
allocated datarate/latency in demand-based schemes in a more allocated datarate/latency in demand-based schemes in a more
deterministic manner. deterministic manner.
6. DLEP Message Processing 5. DLEP Message Processing
Communication between DLEP peers consists of a bidirectional stream Communication between DLEP peers consists of a bidirectional stream
of signals, each signal consisting of a signal header and an of signals, each signal consisting of a signal header and an
unordered list of data items. Both signal headers and data items are unordered list of data items. Both signal headers and data items are
encoded as TLV (Type-Length-Value) structures. In this document, the encoded as TLV (Type-Length-Value) structures. In this document, the
data items following the signal header are described as being data items following the signal header are described as being
'contained in' the signal. 'contained in' the signal.
All integer values in all TLV structures MUST be in network byte- All integer values in all TLV structures MUST be in network byte-
order. order.
There is no restriction on the order of data items following a There is no restriction on the order of data items following a
signal, and the multiplicity of duplicate data items is defined by signal, and the multiplicity of duplicate data items is defined by
the definition of the signal declared by the type in the signal the definition of the signal declared by the type in the signal
header. header.
If an unrecognized, or unexpected signal is received, or a received If an unrecognized, or unexpected signal is received, or a received
signal contains unrecognized, invalid or disallowed duplicate data signal contains unrecognized, invalid or disallowed duplicate data
items, the receiving peer MUST terminate the session by issuing a items, the receiving peer MUST terminate the session by issuing a
Peer Termination signal (Section 7.7) with a Status data item Peer Termination signal (Section 6.7) with a Status data item
(Section 8.2) containing the most relevant status code, and then (Section 7.2) containing the most relevant status code, and then
close the TCP connection: close the TCP connection.
6.1. DLEP Signal Header 5.1. DLEP Signal Header
The DLEP signal header contains the following fields: The DLEP signal header contains the following fields:
0 1 2 3 0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Signal Type | Length | Data Items... | Signal Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: DLEP Signal Header Figure 3: DLEP Signal Header
Signal Type: One of the DLEP Signal Type values defined in this Signal Type: One of the DLEP Signal Type values defined in this
document. document.
Length: The length, expressed as a 16-bit unsigned integer, of all Length: The length, expressed as a 16-bit unsigned integer, of all
of the DLEP data items associated with this signal. This length of the DLEP data items associated with this signal. This length
does not include the length of the header itself does not include the length of the header itself
Data Items: One or more DLEP data items, encoded in TLVs, as defined The DLEP Signal Header is immediately followed bu one or more DLEP
in this document. data items, encoded in TLVs, as defined in this document.
6.2. DLEP Generic Data Item 5.2. DLEP Generic Data Item
All DLEP data items contain the following fields: All DLEP data items contain the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length | Value... | | Data Item Type| Length | Value... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: DLEP Generic Data Item Figure 4: DLEP Generic Data Item
Data Item Type: An 8-bit unsigned integer field specifying the data Data Item Type: An 8-bit unsigned integer field specifying the data
item being sent. item being sent.
Length: An 8-bit length of the value field of the data item. Length: The length, expressed as an 8-bit unsigned integer, of the
value field of the data item.
Value: A field of length <Length> which contains data specific to a Value: A field of length <Length> which contains data specific to a
particular data item. particular data item.
7. DLEP Signals 6. DLEP Signals
As mentioned above, all DLEP signals begin with the DLEP signal As mentioned above, all DLEP signals begin with the DLEP signal
header structure. Therefore, in the following descriptions of header structure. Therefore, in the following descriptions of
specific signals, this header structure is assumed, and will not be specific signals, this header structure is assumed, and will not be
replicated. replicated.
Following is the set of MANDATORY signals that must be recognized by Following is the set of MANDATORY signals that must be recognized by
a DLEP compliant implementation. As mentioned before, not all a DLEP compliant implementation. As mentioned before, not all
signals may be used during a session, but an implementation MUST signals may be used during a session, but an implementation MUST
correctly process these signals when received. correctly process these signals when received.
The mandatory DLEP signals are: The mandatory DLEP signals are:
+---------+-------------------------------+---------------+ +---------+-------------------------------+---------------+
| Signal | Description | Section | | Signal | Description | Section |
+---------+-------------------------------+---------------+ +---------+-------------------------------+---------------+
| TBD | Peer Discovery | Section 7.1 | | TBD | Peer Discovery | Section 6.1 |
| TBD | Peer Offer | Section 7.2 | | TBD | Peer Offer | Section 6.2 |
| TBD | Peer Initialization | Section 7.3 | | TBD | Peer Initialization | Section 6.3 |
| TBD | Peer Initialization ACK | Section 7.4 | | TBD | Peer Initialization ACK | Section 6.4 |
| TBD | Peer Update | Section 7.5 | | TBD | Peer Update | Section 6.5 |
| TBD | Peer Update ACK | Section 7.6 | | TBD | Peer Update ACK | Section 6.6 |
| TBD | Peer Termination | Section 7.7 | | TBD | Peer Termination | Section 6.7 |
| TBD | Peer Termination ACK | Section 7.8 | | TBD | Peer Termination ACK | Section 6.8 |
| TBD | Destination Up | Section 7.9 | | TBD | Destination Up | Section 6.9 |
| TBD | Destination Up ACK | Section 7.10 | | TBD | Destination Up ACK | Section 6.10 |
| TBD | Destination Down | Section 7.11 | | TBD | Destination Down | Section 6.11 |
| TBD | Destination Down ACK | Section 7.12 | | TBD | Destination Down ACK | Section 6.12 |
| TBD | Destination Update | Section 7.13 | | TBD | Destination Update | Section 6.13 |
| TBD | Heartbeat | Section 7.14 | | TBD | Heartbeat | Section 6.14 |
| TBD | Link Characteristics Request | Section 7.15 | | TBD | Link Characteristics Request | Section 6.15 |
| TBD | Link Characteristics ACK | Section 7.16 | | TBD | Link Characteristics ACK | Section 6.16 |
+---------+-------------------------------+---------------+ +---------+-------------------------------+---------------+
7.1. Peer Discovery Signal 6.1. Peer Discovery Signal
A Peer Discovery signal SHOULD be sent by a router to discover DLEP A Peer Discovery signal SHOULD be sent by a router to discover DLEP
routers in the network. The Peer Offer signal (Section 7.2) is modems in the network. The Peer Offer signal (Section 6.2) is
required to complete the discovery process. Implementations MAY required to complete the discovery process. Implementations MAY
implement their own retry heuristics in cases where it is determined implement their own retry heuristics in cases where it is determined
the Peer Discovery signal has timed out. the Peer Discovery signal has timed out.
To construct a Peer Discovery signal, the Signal Type value in the To construct a Peer Discovery signal, the Signal Type value in the
signal header is set to DLEP_PEER_DISCOVERY (value TBD). signal header is set to DLEP_PEER_DISCOVERY (value TBD).
The Peer Discovery signal MUST contain one of each of the following The Peer Discovery signal MUST contain the following data item:
data items:
o DLEP Version (Section 8.1) o DLEP Version (Section 7.1)
o Heartbeat Interval (Section 8.5) The Peer Discovery signal MAY contain the following data item:
7.2. Peer Offer Signal o Peer Type (Section 7.5)
6.2. Peer Offer Signal
A Peer Offer signal MUST be sent by a DLEP modem in response to a A Peer Offer signal MUST be sent by a DLEP modem in response to a
Peer Discovery signal (Section 7.1). Upon receipt, and processing, valid Peer Discovery signal (Section 6.1).
of a Peer Offer signal, the router responds by issuing a TCP connect
to the address/port combination specified in the received Peer Offer.
The Peer Offer signal MUST be sent to the unicast address of the The Peer Offer signal MUST be sent to the unicast address of the
originator of Peer Discovery. originator of the Peer Discovery signal.
To construct a Peer Offer signal, the Signal Type value in the signal To construct a Peer Offer signal, the Signal Type value in the signal
header is set to DLEP_PEER_OFFER (value TBD). header is set to DLEP_PEER_OFFER (value TBD).
The Peer Offer signal MUST contain one of each of the following data The Peer Offer signal MUST contain the following data item:
items:
o DLEP Version (Section 8.1)
o Heartbeat Interval (Section 8.5)
The Peer Offer signal MAY contain one of each of the following data o DLEP Version (Section 7.1)
items:
o Peer Type (Section 8.4) The Peer Offer signal MAY contain the following data item:
o DLEP Port (Section 8.3) o Peer Type (Section 7.5)
The Peer Offer signal MAY contain one or more of any of the following The Peer Offer signal MAY contain one or more of any of the following
data items, with different values: data items, with different values:
o IPv4 Address (Section 8.9), with Add/Drop indicator = 1 o IPv4 Connection Point (Section 7.3)
o IPv6 Address (Section 8.10), with Add/Drop indicator = 1
If the Peer Offer signal includes a DLEP Port data item, the port o IPv6 Connection Point (Section 7.4)
number specified MUST be used to establish the TCP session. If the
DLEP Port number is omitted, the receiver MUST use the DLEP well-
known port number (Section 11.7) to establish the TCP connection.
The IP Address data items indicate the unicast address the receiver The IP Connection Point data items indicate the unicast address the
of Peer Offer MUST use when connecting the DLEP TCP session. If receiver of Peer Offer MUST use when connecting the DLEP TCP session.
multiple IP Address items are present in the Peer Offer signal, If multiple IP Connection Point data items are present in the Peer
implementations MAY use their own heuristics to select the address to Offer signal, implementations MAY use their own heuristics to select
connect to. If no IP Address data items are included in the Peer the address to connect to. If no IP Connection Point data items are
Offer signal, the receiver MUST use the origin address of the signal included in the Peer Offer signal, the receiver MUST use the origin
as the IP address to establish the TCP connection. address of the signal as the IP address, and the DLEP well-known port
number (Section 10.7) to establish the TCP connection.
7.3. Peer Initialization Signal 6.3. Peer Initialization Signal
A Peer Initialization signal MUST be sent by a router as the first A Peer Initialization signal MUST be sent by a router as the first
signal of the DLEP TCP session. It is sent by the router after a TCP signal of the DLEP TCP session. It is sent by the router after a TCP
connect to an address/port combination that was obtained either via connect to an address/port combination that was obtained either via
receipt of a Peer Offer, or from a-priori configuration. receipt of a Peer Offer, or from a-priori configuration.
If any optional extensions are supported by the implementation, they If any optional extensions are supported by the implementation, they
MUST be enumerated in the Extensions Supported data item. If an MUST be enumerated in the Extensions Supported data item. If an
Extensions Supported data item does NOT exist in a Peer Extensions Supported data item does NOT exist in a Peer
Initialization signal, the receiver of the signal MUST conclude that Initialization signal, the receiver of the signal MUST conclude that
skipping to change at page 19, line 33 skipping to change at page 19, line 24
items in a Peer Initialization signal, the receiver of the signal items in a Peer Initialization signal, the receiver of the signal
MUST conclude that NO experimental definitions are in use by the MUST conclude that NO experimental definitions are in use by the
sender. sender.
To construct a Peer Initialization signal, the Signal Type value in To construct a Peer Initialization signal, the Signal Type value in
the signal header is set to DLEP_PEER_INITIALIZATION (value TBD). the signal header is set to DLEP_PEER_INITIALIZATION (value TBD).
The Peer Initialization signal MUST contain one of each of the The Peer Initialization signal MUST contain one of each of the
following data items: following data items:
o DLEP Version (Section 8.1) o DLEP Version (Section 7.1)
o Heartbeat Interval (Section 8.5) o Heartbeat Interval (Section 7.6)
The Peer Initialization signal MAY contain one of each of the The Peer Initialization signal MAY contain one of each of the
following data items: following data items:
o Peer Type (Section 8.4) o Peer Type (Section 7.5)
o Extensions Supported (Section 8.6) o Extensions Supported (Section 7.7)
The Peer Initialization signal MAY contain one or more of any of the The Peer Initialization signal MAY contain one or more of any of the
following data items, with different values: following data items, with different values:
o Experimental Definition (Section 8.7) o Experimental Definition (Section 7.8)
7.4. Peer Initialization ACK Signal A Peer Initialization signal MUST be acknowledged by the receiver
issuing a Peer Initialization ACK signal (Section 6.4).
6.4. Peer Initialization ACK Signal
A Peer Initialization ACK signal MUST be sent in response to a A Peer Initialization ACK signal MUST be sent in response to a
received Peer Initialization signal (Section 7.3). The Peer received Peer Initialization signal (Section 6.3). The Peer
Initialization ACK signal completes the TCP-level DLEP session Initialization ACK signal completes the DLEP session establishment;
establishment; the sender of the signal should transition to an 'in- the sender of the signal should transition to an 'in- session' state
session' state when the signal is sent, and the receiver should when the signal is sent, and the receiver should transition to the
transition to the 'in-session' state upon receipt (and successful 'in-session' state upon receipt (and successful parsing) of an
parsing) of a Peer Initialization ACK signal. acceptable Peer Initialization ACK signal.
All supported metric data items MUST be included in the Peer All supported metric data items MUST be included in the Peer
Initialization ACK signal, with default values to be used on a Initialization ACK signal, with default values to be used on a
'modem-wide' basis. This can be viewed as the modem 'declaring' all 'modem-wide' basis. This can be viewed as the modem 'declaring' all
supported metrics at DLEP session initialization. Receipt of any supported metrics at DLEP session initialization. Receipt of any
DLEP signal containing a metric data item NOT included in the Peer DLEP signal containing a metric data item NOT included in the Peer
Initialization ACK signal MUST be treated as an error, resulting in Initialization ACK signal MUST be treated as an error, resulting in
the termination of the DLEP session between router and modem. the termination of the DLEP session between router and modem.
If any optional extensions are supported by the modem, they MUST be If any optional extensions are supported by the modem, they MUST be
skipping to change at page 20, line 47 skipping to change at page 20, line 37
been successfully exchanged, implementations MUST only utilize been successfully exchanged, implementations MUST only utilize
extensions and experimental definitions that are supported by BOTH extensions and experimental definitions that are supported by BOTH
peers. peers.
To construct a Peer Initialization ACK signal, the Signal Type value To construct a Peer Initialization ACK signal, the Signal Type value
in the signal header is set to DLEP_PEER_INIT_ACK (value TBD). in the signal header is set to DLEP_PEER_INIT_ACK (value TBD).
The Peer Initialization ACK signal MUST contain one of each of the The Peer Initialization ACK signal MUST contain one of each of the
following data items: following data items:
o DLEP Version (Section 8.1) o DLEP Version (Section 7.1)
o Heartbeat Interval (Section 8.5) o Heartbeat Interval (Section 7.6)
o Maximum Data Rate (Receive) (Section 8.13) o Maximum Data Rate (Receive) (Section 7.14)
o Maximum Data Rate (Transmit) (Section 8.14)
o Current Data Rate (Receive) (Section 8.15) o Maximum Data Rate (Transmit) (Section 7.15)
o Current Data Rate (Transmit) (Section 8.16) o Current Data Rate (Receive) (Section 7.16)
o Latency (Section 8.17) o Current Data Rate (Transmit) (Section 7.17)
The Peer Initialization ACK signal MAY contain one of each of the o Latency (Section 7.18)
following data items: The Peer Initialization ACK signal MUST contain one of each of the
following data items, if the data item will be used during the
lifetime of the session:
o Status (Section 8.2) o Resources (Receive) (Section 7.19)
o Peer Type (Section 8.4) o Resources (Transmit) (Section 7.20)
o Resources (Receive) (Section 8.18) o Relative Link Quality (Receive) (Section 7.21)
o Resources (Transmit) (Section 8.19) o Relative Link Quality (Transmit) (Section 7.22)
o Relative Link Quality (Receive) (Section 8.20) The Peer Initialization ACK signal MAY contain one of each of the
following data items:
o Relative Link Quality (Transmit) (Section 8.21) o Status (Section 7.2)
o Extensions Supported (Section 8.6) o Peer Type (Section 7.5)
o Extensions Supported (Section 7.7)
The Peer Initialization ACK signal MAY contain one or more of any of The Peer Initialization ACK signal MAY contain one or more of any of
the following data items, with different values: the following data items, with different values:
o Experimental Definition (Section 8.7) o Experimental Definition (Section 7.8)
7.5. Peer Update Signal 6.5. Peer Update Signal
A Peer Update signal MAY be sent by a DLEP peer to indicate local A Peer Update signal MAY be sent by a DLEP peer to indicate local
Layer 3 address changes, or for metric changes on a modem-wide basis. Layer 3 address changes, or metric changes on a modem-wide basis.
For example, addition of an IPv4 address to the router MAY prompt a For example, addition of an IPv4 address to the router MAY prompt a
Peer Update signal to its attached DLEP modems. Also, a modem that Peer Update signal to its attached DLEP modems. Also, for example, a
changes its Maximum Data Rate for all destinations MAY reflect that modem that changes its Maximum Data Rate (Receive) for all
change via a Peer Update signal to its attached router(s). destinations MAY reflect that change via a Peer Update signal to its
attached router(s).
Concerning Layer 3 addresses, if the modem is capable of Concerning Layer 3 addresses, if the modem is capable of
understanding and forwarding this information (via proprietary understanding and forwarding this information (via proprietary
mechanisms), the address update would prompt any remote DLEP modems mechanisms), the address update would prompt any remote DLEP modems
(DLEP-enabled modems in a remote node) to issue a Destination Update (DLEP-enabled modems in a remote node) to issue a Destination Update
signal (Section 7.13) to their local routers with the new (or signal (Section 6.13) to their local routers with the new (or
deleted) addresses. Modems that do not track Layer 3 addresses deleted) addresses. Modems that do not track Layer 3 addresses
SHOULD silently parse and ignore the Peer Update signal. Modems that SHOULD silently parse and ignore the Peer Update signal. Modems that
track Layer 3 addresses MUST acknowledge the Peer Update with a Peer track Layer 3 addresses MUST acknowledge the Peer Update with a Peer
Update ACK signal (Section 7.6). Routers receiving a Peer Update Update ACK signal (Section 6.6).
with metric changes MUST apply the new metric to all destinations
(remote nodes) accessible via the modem. Supporting implementations
are free to employ heuristics to retransmit Peer Update signals. The
sending of Peer Update signals for Layer 3 address changes SHOULD
cease when a either participant (router or modem) determines that the
other implementation does NOT support Layer 3 address tracking.
If metrics are supplied with the Peer Update signal (e.g., Maximum If metrics are supplied with the Peer Update signal (e.g., Maximum
Data Rate), these metrics are considered to be modem-wide, and Data Rate), these metrics are considered to be modem-wide, and
therefore MUST be applied to all destinations in the information base therefore MUST be applied to all destinations in the information base
associated with the router/modem session. associated with the router/modem session.
Supporting implementations are free to employ heuristics to
retransmit Peer Update signals. The sending of Peer Update signals
for Layer 3 address changes SHOULD cease when either participant
(router or modem) determines that the other implementation does NOT
support Layer 3 address tracking.
To construct a Peer Update signal, the Signal Type value in the To construct a Peer Update signal, the Signal Type value in the
signal header is set to DLEP_PEER_UPDATE (value TBD). signal header is set to DLEP_PEER_UPDATE (value TBD).
The Peer Update signal MAY contain one of each of the following data The Peer Update signal MAY contain one of each of the following data
items: items:
o Maximum Data Rate (Receive) (Section 8.13) o Maximum Data Rate (Receive) (Section 7.14)
o Maximum Data Rate (Transmit) (Section 8.14) o Maximum Data Rate (Transmit) (Section 7.15)
o Current Data Rate (Receive) (Section 8.15) o Current Data Rate (Receive) (Section 7.16)
o Current Data Rate (Transmit) (Section 8.16) o Current Data Rate (Transmit) (Section 7.17)
o Latency (Section 8.17) o Latency (Section 7.18)
o Resources (Receive) (Section 8.18) o Resources (Receive) (Section 7.19)
o Resources (Transmit) (Section 8.19) o Resources (Transmit) (Section 7.20)
o Relative Link Quality (Receive) (Section 8.20) o Relative Link Quality (Receive) (Section 7.21)
o Relative Link Quality (Transmit) (Section 8.21) o Relative Link Quality (Transmit) (Section 7.22)
The Peer Update signal MAY contain one or more of the following data The Peer Update signal MAY contain one or more of the following data
items, with different values: items, with different values:
o IPv4 Address (Section 8.9) o IPv4 Address (Section 7.10)
o IPv6 Address (Section 8.10) o IPv6 Address (Section 7.11)
7.6. Peer Update ACK Signal A Peer Update signal MUST be acknowledged by the receiver issuing a
Peer Update ACK signal (Section 6.6).
A Peer Update ACK signal MUST be sent by implementations supporting 6.6. Peer Update ACK Signal
Layer 3 address tracking and/or modem-wide metrics to indicate
whether a Peer Update signal (Section 7.5) was successfully A Peer Update ACK signal MUST be sent by implementations to indicate
processed. If the Peer Update ACK is issued, it MUST contain a whether a Peer Update signal (Section 6.5) was successfully received.
Status data item, indicating the success or failure of processing the
received Peer Update.
To construct a Peer Update ACK signal, the Signal Type value in the To construct a Peer Update ACK signal, the Signal Type value in the
signal header is set to DLEP_PEER_UPDATE_ACK (value TBD). signal header is set to DLEP_PEER_UPDATE_ACK (value TBD).
The Peer Update ACK signal MAY contain one of each of the following The Peer Update ACK signal MAY contain one of each of the following
data items: data items:
o Status (Section 8.2) o Status (Section 7.2)
A receiver of a Peer Update ACK signal without a Status data item A receiver of a Peer Update ACK signal without a Status data item
MUST behave as if a Status data item with code 'Success' had been MUST behave as if a Status data item with code 'Success' had been
received. received.
7.7. Peer Termination Signal 6.7. Peer Termination Signal
A Peer Termination signal MUST be sent by a DLEP participant when the A Peer Termination signal MUST be sent by a DLEP participant when the
router/modem session needs to be terminated. Implementations router/modem session needs to be terminated. Implementations
receiving a Peer Termination signal MUST send a Peer Termination ACK receiving a Peer Termination signal MUST send a Peer Termination ACK
signal (Section 7.8) to confirm the termination process. The sender signal (Section 6.8) to confirm the termination process.
of a Peer Termination signal is free to define its heuristics in
event of a timeout. The receiver of a Peer Termination signal MUST The receiver of a Peer Termination signal MUST release all resources
release all resources allocated for the router/modem session, and allocated for the router/modem session, and MUST eliminate all
MUST eliminate all destinations in the information base accessible destinations in the information base accessible via the router/modem
via the router/modem pair represented by the session. Router and pair represented by the session. Router and modem state machines are
modem state machines are returned to the 'discovery' state. No returned to the 'discovery' state. No Destination Down signals
Destination Down signals (Section 7.11) are sent. (Section 6.11) are sent.
The sender of a Peer Termination signal is free to define its
heuristics in event of a timeout. It may resend the Peer Termination
or free resources and return to the 'discovery' state.
To construct a Peer Termination signal, the Signal Type value in the To construct a Peer Termination signal, the Signal Type value in the
signal header is set to DLEP_PEER_TERMINATION (value TBD). signal header is set to DLEP_PEER_TERMINATION (value TBD).
The Peer Termination signal MAY contain one of each of the following The Peer Termination signal MAY contain one of each of the following
data items: data items:
o Status (Section 8.2) o Status (Section 7.2)
A receiver of a Peer Termination signal without a Status data item A receiver of a Peer Termination signal without a Status data item
MUST behave as if a Status data item with status code 'Success' had MUST behave as if a Status data item with status code 'Success',
been received. implying graceful termination, had been received.
7.8. Peer Termination ACK Signal A Peer Termination signal MUST be acknowledged by the receiver
issuing a Peer Termination ACK signal (Section 6.8).
6.8. Peer Termination ACK Signal
A Peer Termination ACK signal MUST be sent by a DLEP peer in response A Peer Termination ACK signal MUST be sent by a DLEP peer in response
to a received Peer Termination signal (Section 7.7). Receipt of a to a received Peer Termination signal (Section 6.7). Receipt of a
Peer Termination ACK signal completes the teardown of the router/ Peer Termination ACK signal completes the teardown of the router/
modem session. modem session.
To construct a Peer Termination ACK signal, the Signal Type value in To construct a Peer Termination ACK signal, the Signal Type value in
the signal header is set to DLEP_PEER_TERMINATION_ACK (value TBD). the signal header is set to DLEP_PEER_TERMINATION_ACK (value TBD).
The Peer Termination ACK signal MAY contain one of each of the The Peer Termination ACK signal MAY contain one of each of the
following data items: following data items:
o Status (Section 8.2) o Status (Section 7.2)
A receiver of a Peer Termination ACK signal without a Status data A receiver of a Peer Termination ACK signal without a Status data
item MUST behave as if a Status data item with status code 'Success' item MUST behave as if a Status data item with status code 'Success',
had been received. implying graceful termination, had been received.
7.9. Destination Up Signal 6.9. Destination Up Signal
A DLEP participant MUST send a Destination Up signal to report that a A Destination Up signal can be sent either by the modem, to indicate
new destination has been detected. A Destination Up ACK signal
(Section 7.10) is required to confirm a received Destination Up. A
Destination Up signal can be sent either by the modem, to indicate
that a new remote node has been detected, or by the router, to that a new remote node has been detected, or by the router, to
indicate the presence of a new logical destination (e.g., a Multicast indicate the presence of a new logical destination (e.g., a Multicast
group) exists in the network. group) in the network.
The sender of the Destination Up signal is free to define its retry A Destination Up signal MUST be acknowledged by the receiver issuing
heuristics in event of a timeout. When a Destination Up signal is a Destination Up ACK signal (Section 6.10). The sender of the
received and successfully processed, the receiver should add Destination Up signal is free to define its retry heuristics in event
knowledge of the new destination to its information base, indicating of a timeout. When a Destination Up signal is received and
that the destination is accessible via the modem/router pair. successfully processed, the receiver should add knowledge of the new
destination to its information base, indicating that the destination
is accessible via the modem/router pair.
To construct a Destination Up signal, the Signal Type value in the To construct a Destination Up signal, the Signal Type value in the
signal header is set to DLEP_DESTINATION_UP (value TBD). signal header is set to DLEP_DESTINATION_UP (value TBD).
The Destination Up signal MUST contain one of each of the following The Destination Up signal MUST contain one of each of the following
data items: data items:
o MAC Address (Section 8.8) o MAC Address (Section 7.9)
The Destination Up signal MAY contain one of each of the following The Destination Up signal MAY contain one of each of the following
data items: data items:
o Maximum Data Rate (Receive) (Section 8.13) o Maximum Data Rate (Receive) (Section 7.14)
o Maximum Data Rate (Transmit) (Section 8.14) o Maximum Data Rate (Transmit) (Section 7.15)
o Current Data Rate (Receive) (Section 7.16)
o Current Data Rate (Receive) (Section 8.15) o Current Data Rate (Transmit) (Section 7.17)
o Current Data Rate (Transmit) (Section 8.16) o Latency (Section 7.18)
o Latency (Section 8.17) o Resources (Receive) (Section 7.19)
o Resources (Receive) (Section 8.18)
o Resources (Transmit) (Section 8.19) o Resources (Transmit) (Section 7.20)
o Relative Link Quality (Receive) (Section 8.20) o Relative Link Quality (Receive) (Section 7.21)
o Relative Link Quality (Transmit) (Section 8.21) o Relative Link Quality (Transmit) (Section 7.22)
The Destination Up signal MAY contain one or more of the following The Destination Up signal MAY contain one or more of the following
data items, with different values: data items, with different values:
o IPv4 Address (Section 8.9) o IPv4 Address (Section 7.10)
o IPv6 Address (Section 8.10) o IPv6 Address (Section 7.11)
o IPv4 Attached Subnet (Section 8.11) o IPv4 Attached Subnet (Section 7.12)
o IPv6 Attached Subnet (Section 8.12) o IPv6 Attached Subnet (Section 7.13)
If the sender has IPv4 and/or IPv6 address information for a If the sender has IPv4 and/or IPv6 address information for a
destination it SHOULD include the relevant data items in the destination it SHOULD include the relevant data items in the
Destination Up signal, reducing the need for the receiver to probe Destination Up signal, reducing the need for the receiver to probe
for any address. for any address.
7.10. Destination Up ACK Signal 6.10. Destination Up ACK Signal
A DLEP participant MUST send a Destination Up ACK signal to indicate A DLEP participant MUST send a Destination Up ACK signal to indicate
whether a Destination Up signal (Section 7.9) was successfully whether a Destination Up signal (Section 6.9) was successfully
processed. processed.
To construct a Destination Up ACK signal, the Signal Type value in To construct a Destination Up ACK signal, the Signal Type value in
the signal header is set to DLEP_DESTINATION_UP_ACK (value TBD). the signal header is set to DLEP_DESTINATION_UP_ACK (value TBD).
The Destination Up ACK signal MUST contain one of each of the The Destination Up ACK signal MUST contain one of each of the
following data items: following data items:
o MAC Address (Section 8.8) o MAC Address (Section 7.9)
The Destination Up ACK signal MAY contain one of each of the The Destination Up ACK signal MAY contain one of each of the
following data items: following data items:
o Status (Section 8.2) o Status (Section 7.2)
A receiver of a Destination Up ACK signal without a Status data item A receiver of a Destination Up ACK signal without a Status data item
MUST behave as if a Status data item with status code 'Success' had MUST behave as if a Status data item with status code 'Success' had
been received. been received.
7.11. Destination Down Signal 6.11. Destination Down Signal
A DLEP peer MUST send a Destination Down signal to report when a A DLEP peer MUST send a Destination Down signal to report when a
destination (a remote node or a multicast group) is no longer destination (a remote node or a multicast group) is no longer
reachable. A Destination Down ACK signal (Section 7.12) MUST be sent reachable. A Destination Down ACK signal (Section 6.12) MUST be sent
by the recipient of a Destination Down signal to confirm that the by the recipient of a Destination Down signal to confirm that the
relevant data has been removed from the information base. The sender relevant data has been removed from the information base. The sender
of the Destination Down signal is free to define its retry heuristics of the Destination Down signal is free to define its retry heuristics
in event of a timeout. in event of a timeout.
To construct a Destination Down signal, the Signal Type value in the To construct a Destination Down signal, the Signal Type value in the
signal header is set to DLEP_DESTINATION_DOWN (value TBD). signal header is set to DLEP_DESTINATION_DOWN (value TBD).
The Destination Down signal MUST contain one of each of the following The Destination Down signal MUST contain one of each of the following
data items: data items:
o MAC Address (Section 8.8) o MAC Address (Section 7.9)
7.12. Destination Down ACK Signal 6.12. Destination Down ACK Signal
A DLEP participant MUST send a Destination Down ACK signal to A DLEP participant MUST send a Destination Down ACK signal to
indicate whether a received Destination Down signal (Section 7.11) indicate whether a received Destination Down signal (Section 6.11)
was successfully processed. If successfully processed, the sender of was successfully processed. If successfully processed, the sender of
the ACK MUST have removed all entries in the information base that the ACK MUST have removed all entries in the information base that
pertain to the referenced destination. pertain to the referenced destination.
To construct a Destination Down ACK signal, the Signal Type value in To construct a Destination Down ACK signal, the Signal Type value in
the signal header is set to DLEP_DESTINATION_DOWN_ACK (value TBD). the signal header is set to DLEP_DESTINATION_DOWN_ACK (value TBD).
The Destination Down ACK signal MUST contain one of each of the The Destination Down ACK signal MUST contain one of each of the
following data items: following data items:
o MAC Address (Section 8.8) o MAC Address (Section 7.9)
The Destination Down ACK signal MAY contain one of each of the The Destination Down ACK signal MAY contain one of each of the
following data items: following data items:
o Status (Section 8.2) o Status (Section 7.2)
A receiver of a Destination Down ACK signal without a Status data A receiver of a Destination Down ACK signal without a Status data
item MUST behave as if a Status data item with status code 'Success' item MUST behave as if a Status data item with status code 'Success'
had been received. had been received.
7.13. Destination Update Signal 6.13. Destination Update Signal
A DLEP participant SHOULD send the Destination Update signal when it A DLEP participant SHOULD send the Destination Update signal when it
detects some change in the information base for a given destination detects some change in the information base for a given destination
(remote node or multicast group). Some examples of changes that (remote node or multicast group). Some examples of changes that
would prompt a Destination Update signal are: would prompt a Destination Update signal are:
o Change in link metrics (e.g., Data Rates) o Change in link metrics (e.g., Data Rates)
o Layer 3 addressing change (for implementations that support it) o Layer 3 addressing change
To construct a Destination Update signal, the Signal Type value in To construct a Destination Update signal, the Signal Type value in
the signal header is set to DLEP_DESTINATION_UPDATE (value TBD). the signal header is set to DLEP_DESTINATION_UPDATE (value TBD).
The Destination Update signal MUST contain one of each of the The Destination Update signal MUST contain one of each of the
following data items: following data items:
o MAC Address (Section 8.8) o MAC Address (Section 7.9)
The Destination Update signal MAY contain one of each of the The Destination Update signal MAY contain one of each of the
following data items: following data items:
o Maximum Data Rate (Receive) (Section 8.13) o Maximum Data Rate (Receive) (Section 7.14)
o Maximum Data Rate (Transmit) (Section 8.14) o Maximum Data Rate (Transmit) (Section 7.15)
o Current Data Rate (Receive) (Section 8.15) o Current Data Rate (Receive) (Section 7.16)
o Current Data Rate (Transmit) (Section 8.16) o Current Data Rate (Transmit) (Section 7.17)
o Latency (Section 8.17) o Latency (Section 7.18)
o Resources (Receive) (Section 8.18) o Resources (Receive) (Section 7.19)
o Resources (Transmit) (Section 8.19) o Resources (Transmit) (Section 7.20)
o Relative Link Quality (Receive) (Section 8.20) o Relative Link Quality (Receive) (Section 7.21)
o Relative Link Quality (Transmit) (Section 8.21) o Relative Link Quality (Transmit) (Section 7.22)
The Destination Update signal MAY contain one or more of the The Destination Update signal MAY contain one or more of the
following data items, with different values: following data items, with different values:
o IPv4 Address (Section 8.9) o IPv4 Address (Section 7.10)
o IPv6 Address (Section 8.10)
o IPv4 Attached Subnet (Section 8.11) o IPv6 Address (Section 7.11)
o IPv6 Attached Subnet (Section 8.12) o IPv4 Attached Subnet (Section 7.12)
o IPv6 Attached Subnet (Section 7.13)
7.14. Heartbeat Signal 6.14. Heartbeat Signal
A Heartbeat signal SHOULD be sent by a DLEP participant every N A Heartbeat signal SHOULD be sent by a DLEP participant every N
seconds, where N is defined in the Heartbeat Interval field of the seconds, where N is defined in the Heartbeat Interval data item of
Peer Initialization signal (Section 7.3) or Peer Initialization ACK the Peer Initialization signal (Section 6.3) or Peer Initialization
signal (Section 7.4). Note that implementations setting the ACK signal (Section 6.4). Note that implementations setting the
Heartbeat Interval to 0 effectively set the interval to an infinite Heartbeat Interval to 0 effectively set the interval to an infinite
value, therefore, in those cases, this signal SHOULD NOT be sent. value, therefore, in those cases, this signal SHOULD NOT be sent.
The signal is used by participants to detect when a DLEP session The signal is used by participants to detect when a DLEP session
partner (either the modem or the router) is no longer communicating. partner (either the modem or the router) is no longer communicating.
Participants SHOULD allow two (2) heartbeat intervals to expire with Participants SHOULD allow two (2) heartbeat intervals to expire with
no traffic on the router/modem session before initiating DLEP session no traffic on the router/modem session before initiating DLEP session
termination procedures. termination procedures.
To construct a Heartbeat signal, the Signal Type value in the signal To construct a Heartbeat signal, the Signal Type value in the signal
header is set to DLEP_PEER_HEARTBEAT (value TBD). header is set to DLEP_PEER_HEARTBEAT (value TBD).
There are no valid data items for the Heartbeat signal. There are no valid data items for the Heartbeat signal.
7.15. Link Characteristics Request Signal 6.15. Link Characteristics Request Signal
The Link Characteristics Request signal MAY be sent by the router to The Link Characteristics Request signal MAY be sent by the router to
request that the modem initiate changes for specific characteristics request that the modem initiate changes for specific characteristics
of the link. The request can reference either a real (e.g., a remote of the link. The request can reference either a real destination
node), or a logical (e.g., a multicast group) destination within the (e.g., a remote node), or a logical destination (e.g., a multicast
network. group) within the network.
The Link Characteristics Request signal contains either a Current The Link Characteristics Request signal contains either a Current
Data Rate (CDRR or CDRT) data item to request a different datarate Data Rate (CDRR or CDRT) data item to request a different datarate
than what is currently allocated, a Latency data item to request that than what is currently allocated, a Latency data item to request that
traffic delay on the link not exceed the specified value, or both. A traffic delay on the link not exceed the specified value, or both. A
Link Characteristics ACK signal (Section 7.16) is required to Link Characteristics ACK signal (Section 6.16) is required to
complete the request. Issuing a Link Characteristics Request with complete the request. Issuing a Link Characteristics Request with
ONLY the MAC Address data item is a mechanism a peer MAY use to ONLY the MAC Address data item is a mechanism a peer MAY use to
request metrics (via the Link Characteristics ACK) from its partner. request metrics (via the Link Characteristics ACK) from its partner.
The sender of a Link Characteristics Request signal MAY attach a The sender of a Link Characteristics Request signal MAY attach a
timer to the request using the Link Characteristics ACK Timer data timer to the request using the Link Characteristics ACK Timer data
item. If a Link Characteristics ACK signal is received after the item. If a Link Characteristics ACK signal is received after the
timer expires, the sender MUST assume that the request failed. timer expires, the sender MUST NOT assume that the request succeeded.
Implementations are free to define their retry heuristics in event of Implementations are free to define their retry heuristics in event of
a timeout. a timeout.
To construct a Link Characteristics Request signal, the Signal Type To construct a Link Characteristics Request signal, the Signal Type
value in the signal header is set to DLEP_LINK_CHAR_REQ (value TBD). value in the signal header is set to DLEP_LINK_CHAR_REQ (value TBD).
The Link Characteristics Request signal MUST contain one of each of The Link Characteristics Request signal MUST contain one of each of
the following data items: the following data items:
o MAC Address (Section 8.8) o MAC Address (Section 7.9)
The Link Characteristics Request signal MAY contain one of each of The Link Characteristics Request signal MAY contain one of each of
the following data items: the following data items:
o Link Characteristics ACK Timer (Section 8.22) o Link Characteristics ACK Timer (Section 7.23)
o Current Data Rate (Receive) (Section 8.15) o Current Data Rate (Receive) (Section 7.16)
o Current Data Rate (Transmit) (Section 8.16) o Current Data Rate (Transmit) (Section 7.17)
o Latency (Section 8.17) o Latency (Section 7.18)
7.16. Link Characteristics ACK Signal 6.16. Link Characteristics ACK Signal
A DLEP participant MUST send a Link Characteristics ACK signal to A DLEP participant MUST send a Link Characteristics ACK signal to
indicate whether a received Link Characteristics Request signal indicate whether a received Link Characteristics Request signal
(Section 7.15) was successfully processed. The Link Characteristics (Section 6.15) was successfully processed. The Link Characteristics
ACK signal SHOULD contain a complete set of metric data items. It ACK signal SHOULD contain a complete set of metric data items, and
MUST contain the same metric types as the request. The values in the MUST contain a full set (i.e. those declared in the Peer
metric data items in the Link Characteristics ACK signal MUST reflect Initialization ACK signal (Section 6.4)), if metrics were requested
the link characteristics after the request has been processed. by only including a MAC address data item. It MUST contain the same
metric types as the request. The values in the metric data items in
the Link Characteristics ACK signal MUST reflect the link
characteristics after the request has been processed.
If an implementation is not able to alter the characteristics of the If an implementation is not able to alter the characteristics of the
link in the manner requested, then a Status data item with status link in the manner requested, then a Status data item with status
code 'Request Denied' MUST be added to the signal. code 'Request Denied' MUST be added to the signal.
To construct a Link Characteristics Request ACK signal, the Signal To construct a Link Characteristics Request ACK signal, the Signal
Type value in the signal header is set to DLEP_LINK_CHAR_ACK (value Type value in the signal header is set to DLEP_LINK_CHAR_ACK (value
TBD). TBD).
The Link Characteristics ACK signal MUST contain one of each of the The Link Characteristics ACK signal MUST contain one of each of the
following data items: following data items:
o MAC Address (Section 8.8) o MAC Address (Section 7.9)
The Link Characteristics ACK signal MAY contain one of each of the The Link Characteristics ACK signal SHOULD contain one of each of the
following data items: following data items:
o Current Data Rate (Receive) (Section 8.15) o Maximum Data Rate (Receive) (Section 7.14)
o Current Data Rate (Transmit) (Section 8.16) o Maximum Data Rate (Transmit) (Section 7.15)
o Current Data Rate (Receive) (Section 7.16)
o Latency (Section 8.17) o Current Data Rate (Transmit) (Section 7.17)
o Resources (Receive) (Section 8.18)
o Resources (Transmit) (Section 8.19) o Latency (Section 7.18)
o Relative Link Quality (Receive) (Section 8.20) The Link Characteristics ACK signal MAY contain one of each of the
following data items:
o Relative Link Quality (Transmit) (Section 8.21) o Resources (Receive) (Section 7.19)
o Status (Section 8.2) o Resources (Transmit) (Section 7.20)
o Relative Link Quality (Receive) (Section 7.21)
o Relative Link Quality (Transmit) (Section 7.22)
o Status (Section 7.2)
A receiver of a Link Characteristics ACK signal without a Status data A receiver of a Link Characteristics ACK signal without a Status data
item MUST behave as if a Status data item with status code 'Success' item MUST behave as if a Status data item with status code 'Success'
had been received. had been received.
8. DLEP Data Items 7. DLEP Data Items
Following is the list of MANDATORY data items that must be recognized Following is the list of MANDATORY data items that must be recognized
by a DLEP compliant implementation. As mentioned before, not all by a DLEP compliant implementation. As mentioned before, not all
data items need be used during a session, but an implementation MUST data items need be used during a session, but an implementation MUST
correctly process these data items when correctly associated with a correctly process these data items when correctly associated with a
signal. signal.
The mandatory DLEP data items are: The DLEP data items are:
+------------+--------------------------------------+---------------+ +------------+--------------------------------------+---------------+
| Data Item | Description | Section | | Data Item | Description | Section |
+------------+--------------------------------------+---------------+ +------------+--------------------------------------+---------------+
| TBD | DLEP Version | Section 8.1 | | TBD | DLEP Version | Section 7.1 |
| TBD | Status | Section 8.2 | | TBD | Status | Section 7.2 |
| TBD | DLEP Port | Section 8.3 | | TBD | IPv4 Connection Point | Section 7.3 |
| TBD | Peer Type | Section 8.4 | | TBD | IPv6 Connection Point | Section 7.4 |
| TBD | Heartbeat Interval | Section 8.5 | | TBD | Peer Type | Section 7.5 |
| TBD | Extensions Supported | Section 8.6 | | TBD | Heartbeat Interval | Section 7.6 |
| TBD | Experimental Definition | Section 8.7 | | TBD | Extensions Supported | Section 7.7 |
| TBD | MAC Address | Section 8.8 | | TBD | Experimental Definition | Section 7.8 |
| TBD | IPv4 Address | Section 8.9 | | TBD | MAC Address | Section 7.9 |
| TBD | IPv6 Address | Section 8.10 | | TBD | IPv4 Address | Section 7.10 |
| TBD | IPv4 Attached Subnet | Section 8.11 | | TBD | IPv6 Address | Section 7.11 |
| TBD | IPv6 Attached Subnet | Section 8.12 | | TBD | IPv4 Attached Subnet | Section 7.12 |
| TBD | Maximum Data Rate (Receive) MDRR) | Section 8.13 | | TBD | IPv6 Attached Subnet | Section 7.13 |
| TBD | Maximum Data Rate (Transmit) (MDRT) | Section 8.14 | | TBD | Maximum Data Rate (Receive) MDRR) | Section 7.14 |
| TBD | Current Data Rate (Receive) (CDRR) | Section 8.15 | | TBD | Maximum Data Rate (Transmit) (MDRT) | Section 7.15 |
| TBD | Current Data Rate (Transmit) (CDRT) | Section 8.16 | | TBD | Current Data Rate (Receive) (CDRR) | Section 7.16 |
| TBD | Latency | Section 8.17 | | TBD | Current Data Rate (Transmit) (CDRT) | Section 7.17 |
| TBD | Resources (Receive) (RESR) | Section 8.18 | | TBD | Latency | Section 7.18 |
| TBD | Resources (Transmit) (REST) | Section 8.19 | | TBD | Resources (Receive) (RESR) | Section 7.19 |
| TBD | Relative Link Quality (Receive) | Section 8.20 | | TBD | Resources (Transmit) (REST) | Section 7.20 |
| TBD | Relative Link Quality (Receive) | Section 7.21 |
| | (RLQR) | | | | (RLQR) | |
| TBD | Relative Link Quality (Transmit) | Section 8.21 | | TBD | Relative Link Quality (Transmit) | Section 7.22 |
| | (RLQT) | | | | (RLQT) | |
| TBD | Link Characteristics ACK Timer | Section 8.22 | | TBD | Link Characteristics ACK Timer | Section 7.23 |
+------------+--------------------------------------+---------------+ +------------+--------------------------------------+---------------+
8.1. DLEP Version 7.1. DLEP Version
The DLEP Version data item MUST appear in the Peer Discovery The DLEP Version data item MUST appear in the Peer Discovery
(Section 7.1), Peer Offer (Section 7.2), Peer Initialization (Section 6.1), Peer Offer (Section 6.2), Peer Initialization
(Section 7.3) and Peer Initialization ACK (Section 7.4) signals The (Section 6.3) and Peer Initialization ACK (Section 6.4) signals The
Version data item is used to indicate the version of the protocol Version data item is used to indicate the version of the protocol
running in the originator. A DLEP implementation MAY use this running in the originator. A DLEP implementation SHOULD use this
information to decide if the potential session partner is running at information to decide if the potential session partner is running at
a supported level. a supported level.
The DLEP Version data item contains the following fields: The DLEP Version data item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 4 | Major Version | | Data Item Type| Length | Major Version |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Minor Version | | Minor Version |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 4 Length: 4
Major Version: Major version of the DLEP protocol. Major Version: The major version of the DLEP protocol, expressed as
an 16-bit unsigned integer.
Minor Version: Minor version of the DLEP protocol. Minor Version: The minor version of the DLEP protocol, expressed as
an 16-bit unsigned integer.
Support of this draft is indicated by setting the Major Version to Support of this draft is indicated by setting the Major Version to
'0', and the Minor Version to '8' (i.e., Version 0.8). '0', and the Minor Version to '9' (i.e. Version 0.9).
8.2. Status 7.2. Status
The Status data item is MAY appear in the Peer Initialization ACK The Status data item MAY appear in the Peer Initialization ACK
(Section 7.4), Peer Termination (Section 7.7), Peer Termination ACK (Section 6.4), Peer Termination (Section 6.7), Peer Termination ACK
(Section 7.8), Peer Update ACK (Section 7.6), Destination Up ACK (Section 6.8), Peer Update ACK (Section 6.6), Destination Up ACK
(Section 7.10), Destination Down ACK (Section 7.12) and Link (Section 6.10), Destination Down ACK (Section 6.12) and Link
Characteristics ACK (Section 7.16) signals as part of an Characteristics ACK (Section 6.16) signals as part of an
acknowledgement from either the modem or the router, to indicate the acknowledgement from either the modem or the router, to indicate the
success or failure of the previously received signal. success or failure of the previously received signal.
The status data item includes an optional Text field that can be used
to provide a textual description of the status. The use of the Text
field is entirely up to the receiving implementation, i.e., it could
be output to a log file or discarded. If no Text field is supplied
with the Status data item, the Length field MUST be set to 1.
The Status data item contains the following fields: The Status data item contains the following fields:
0 1 2 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 1 | Code | | Data Item Type| Length | Code | Text...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 1 Length: 1 + Length of text
Status Code: One of the codes defined below. Status Code: One of the codes defined below.
+-------------------+-----------------------------------------------+ Text: UTF-8 encoded string, describing an problem, used for
| Status Code | Reason | implementation defined purposes.
+-------------------+-----------------------------------------------+
| Success | The signal was processed successfully. |
| Unknown Signal | The signal was not recognized by the |
| | implementation. |
| Invalid Signal | One or more data items in the signal are |
| | invalid, unexpected or duplicated. |
| Unexpected Signal | The signal was not expected while the machine |
| | was in this state, e.g., a Peer |
| | Initialization signal after session |
| | establishment. |
| Request Denied | The receiver has not completed the request. |
| Timed Out | The request could not be completed in the |
| | time allowed. |
+-------------------+-----------------------------------------------+
8.3. DLEP Port An implementation MUST NOT assume the Text field is NUL-terminated.
The DLEP Port data item MAY appear in the Peer Offer signal +----------------+-------+------------------------------------------+
(Section 7.2). The DLEP Port data item indicates the TCP Port number | Status Code | Value | Reason |
on the DLEP server available for connections. If provided, the +----------------+-------+------------------------------------------+
receiver MUST use this information to perform the TCP connect to the | Success | 0 | The signal was processed successfully. |
DLEP server. | Unknown Signal | TBD | The signal was not recognized by the |
| | | implementation. |
| Invalid Data | TBD | One or more data items in the signal are |
| | | invalid, unexpected or duplicated. |
| Unexpected | TBD | The signal was not expected while the |
| Signal | | machine was in this state, e.g., a Peer |
| | | Initialization signal after session |
| | | establishment. |
| Request Denied | TBD | The receiver has not completed the |
| | | request. |
| Timed Out | TBD | The request could not be completed in |
| | | the time allowed. |
| Invalid | TBD | The destination provided in the signal |
| Destination | | does not match a previously announced |
| | | destination. For example, in the Link |
| | | Characteristic Request ACK signal |
| | | (Section 6.16). |
+----------------+-------+------------------------------------------+
The DLEP Port data item contains the following fields: 7.3. IPv4 Connection Point
The IPv4 Connection Point data item MAY appear in the Peer Offer
signal (Section 6.2). The IPv4 Connection Point data item indicates
the IPv4 address and, optionally, the TCP port number on the DLEP
modem available for connections. If provided, the receiver MUST use
this information to perform the TCP connect to the DLEP server.
The IPv4 Connection Point data item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 2 | TCP Port Number | | Data Item Type| Length | IPv4 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address | TCP Port Number (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD
Length: 4 (or 6 if TCP Port included)
IPv4 Address: The IPv4 address listening on the DLEP modem.
TCP Port Number: TCP Port number on the DLEP modem.
If the Length field is 6, the port number specified MUST be used to
establish the TCP session. If the TCP Port Number is omitted, i.e.
the Length field is 4, the receiver MUST use the DLEP well-known port
number (Section 10.7) to establish the TCP connection.
7.4. IPv6 Connection Point
The IPv6 Connection Point data item MAY appear in the Peer Offer
signal (Section 6.2). The IPv6 Connection Point data item indicates
the IPv6 address and, optionally, the TCP port number on the DLEP
modem available for connections. If provided, the receiver MUST use
this information to perform the TCP connect to the DLEP server.
The IPv4 Connection Point data item contains the following fields:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length | IPv6 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Address | TCP Port Number (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 2 Length: 16 (or 18 if TCP Port included)
TCP Port Number: TCP Port number on the DLEP server. IPv6 Address: The IPv6 address listening on the DLEP modem.
8.4. Peer Type TCP Port Number: TCP Port number on the DLEP modem.
The Peer Type data item MAY appear in both the Peer Discovery If the Length field is 18, the port number specified MUST be used to
(Section 7.1) and Peer Offer (Section 7.2) signals. The Peer Type establish the TCP session. If the TCP Port Number is omitted, i.e.
data item is used by the router and modem to give additional
information as to its type. The peer type is a string and is the Length field is 16, the receiver MUST use the DLEP well-known
envisioned to be used for informational purposes (e.g., as output in port number (Section 10.7) to establish the TCP connection.
a display command).
7.5. Peer Type
The Peer Type data item MAY appear in the Peer Discovery
(Section 6.1), Peer Offer (Section 6.2), Peer Initialization
(Section 6.3) and Peer Initialization ACK (Section 6.4) signals. The
Peer Type data item is used by the router and modem to give
additional information as to its type. The peer type is a string and
is envisioned to be used for informational purposes (e.g., as output
in a display command).
The Peer Type data item contains the following fields: The Peer Type data item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = peer | Peer Type | | Data Item Type| Length | Peer Type |
| | type len | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: Length of peer type string. Length: Length of peer type string.
Peer Type: UTF-8 encoded string. For example, a satellite modem Peer Type: UTF-8 encoded string. For example, a satellite modem
might set this variable to "Satellite terminal". might set this variable to "Satellite terminal".
An implementation MUST NOT assume the Peer Type is NUL-terminated. An implementation MUST NOT assume the Peer Type field is NUL-
terminated.
8.5. Heartbeat Interval 7.6. Heartbeat Interval
The Heartbeat Interval data item MUST appear in the Peer Discovery The Heartbeat Interval data item MUST appear in both the Peer
(Section 7.1), Peer Offer (Section 7.2), Peer Initialization Initialization (Section 6.3) and Peer Initialization ACK
(Section 7.3) and Peer Initialization ACK (Section 7.4) signals to (Section 6.4) signals to indicate the Heartbeat timeout window to be
indicate the desired Heartbeat timeout window. The receiver MUST used by the sender.
either accept the timeout interval supplied by the sender, or reject
the Peer Initialization, and close the socket. Implementations MUST
implement heuristics such that DLEP signals sent/received reset the
timer interval.
The Interval is used to specify a period (in seconds) for Heartbeat The Interval is used to specify a period (in seconds) for Heartbeat
signals (Section 7.14). By specifying an Interval value of 0, signals (Section 6.14). By specifying an Interval value of 0,
implementations MAY indicates the desire to disable Heartbeat signals implementations MAY indicates the desire to disable Heartbeat signals
entirely (i.e., the Interval is set to an infinite value), however, entirely (i.e., the Interval is set to an infinite value). However,
it is strongly recommended that implementations use non 0 timer it is strongly recommended that implementations use non 0 timer
values. values. Implementations MUST implement heuristics such that DLEP
signals sent/received reset the timer interval.
A DLEP session will be considered inactive, and MUST be torn down, by A DLEP session will be considered inactive, and MUST be torn down,
an implementation detecting that two (2) Heartbeat intervals have via the Peer Termination procedure, by an implementation detecting
transpired without receipt of any DLEP signals. that two (2) Heartbeat intervals have transpired without receipt of
any DLEP signals.
The Heartbeat Interval data item contains the following fields: The Heartbeat Interval data item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 2 | Interval | | Data Item Type| Length | Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 2 Length: 2
Interval: 0 = Do NOT use heartbeats on this peer-to-peer session. Interval: 0 = Do NOT use heartbeats on this DLEP session. Non-zero
Non-zero = Interval, in seconds, for heartbeat signals. = Interval, in seconds, for heartbeat signals.
8.6. Extensions Supported 7.7. Extensions Supported
The Extensions Supported data item MAY be used in both the Peer The Extensions Supported data item MAY be used in both the Peer
Initialization and Peer Initialization ACK signals. The Extensions Initialization and Peer Initialization ACK signals. The Extensions
Supported data item is used by the router and modem to negotiate Supported data item is used by the router and modem to negotiate
additional optional functionality they are willing to support. The additional optional functionality they are willing to support. The
Extensions List is a concatenation of the types of each supported Extensions List is a concatenation of the types of each supported
extension, found in the IANA DLEP Extensions repository. extension, found in the IANA DLEP Extensions repository.
The Extensions Supported data item contains the following fields: The Extensions Supported data item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = No. | Extensions List | | Data Item Type| Length | Extensions List |
| | of values | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: Number of Extensions supported. Length: Number of Extensions supported.
Extension List: A list of extensions supported, identified by their Extension List: A list of extensions supported, identified by their
1-octet value as listed in the extensions registry. 1-octet value as listed in the extensions registry.
8.7. Experimental Definition 7.8. Experimental Definition
The Experimental Definition data item MAY be used in both the Peer The Experimental Definition data item MAY be used in both the Peer
Initialization and Peer Initialization ACK signals. The Experimental Initialization and Peer Initialization ACK signals. The Experimental
Definition data item is used by the router and modem to indicate the Definition data item is used by the router and modem to indicate the
formats to be used for experimental signals and data items for the formats to be used for experimental signals and data items for the
given peer session. The formats are identified by using a string given peer session. The formats are identified by using a string
that matches the 'name' given to the experiment. that matches the 'name' given to the experiment.
The Experimental Definition item contains the following fields: The Experimental Definition item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = len. | Experiment Name | | Data Item Type| Length | Experiment Name |
| | of Experiment | |
| | name | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: Length of the name string for the Experiment. Length: Length of the name string for the Experiment.
Experiment Name: UTF-8 encoded string, containing the name of the Experiment Name: UTF-8 encoded string, containing the name of the
experiment being utilized. experiment being utilized.
An implementation receiving this data item MUST compare the received An implementation receiving this data item MUST compare the received
string to a list of experiments that it supports. An implementation string to a list of experiments that it supports.
MUST NOT assume the Experiment Name is NUL-terminated.
8.8. MAC Address An implementation MUST NOT assume the Experiment Name field is NUL-
terminated.
7.9. MAC Address
The MAC address data item MUST appear in all destination-oriented The MAC address data item MUST appear in all destination-oriented
signals (i.e., Destination Up (Section 7.9), Destination Up ACK signals (i.e., Destination Up (Section 6.9), Destination Up ACK
(Section 7.10), Destination Down (Section 7.11), Destination Down ACK (Section 6.10), Destination Down (Section 6.11), Destination Down ACK
(Section 7.12), Destination Update (Section 7.13), Link (Section 6.12), Destination Update (Section 6.13), Link
Characteristics Request (Section 7.15), and Link Characteristics ACK Characteristics Request (Section 6.15), and Link Characteristics ACK
(Section 7.16)). The MAC Address data item contains the address of (Section 6.16)). The MAC Address data item contains the address of
the destination on the remote node. The MAC address MAY be either a the destination on the remote node. The MAC address MAY be either a
physical or a virtual destination. Examples of a virtual destination physical or a virtual destination. Examples of a virtual destination
would be a multicast MAC address, or the broadcast MAC would be a multicast MAC address, or the broadcast MAC
(FF:FF:FF:FF:FF:FF). (FF:FF:FF:FF:FF:FF).
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 6 | MAC Address | | Data Item Type| Length | MAC Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MAC Address | | MAC Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 6 Length: 6
MAC Address: MAC Address of the destination.
MAC Address: MAC Address of the destination (either physical or 7.10. IPv4 Address
virtual).
8.9. IPv4 Address
The IPv4 Address data item MUST appear in the Peer Offer signal The IPv4 Address data item MAY appear in the Peer Update
(Section 7.2), and MAY appear in the Peer Update (Section 7.5), (Section 6.5), Destination Up (Section 6.9) and Destination Update
Destination Up (Section 7.9) and Destination Update (Section 7.13) (Section 6.13) signals. When included in Destination signals, this
signals. When included in Destination signals, this data item data item contains the IPv4 address of the destination. When
contains the IPv4 address of the destination. In the Peer Offer included in the Peer Update signal, this data item contains the IPv4
signal, it contains the IPv4 address of the originating peer to be address of the peer. In either case, the data item also contains an
used to establish a DLEP session. In either case, the data item also indication of whether this is a new or existing address, or is a
contains an indication of whether this is a new or existing address, deletion of a previously known address.
or is a deletion of a previously known address. When used in a Peer
Offer signal the Add/Drop Indicator MUST be 1 (i.e. Add).
The IPv4 Address data item contains the following fields: The IPv4 Address data item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 5 | Add/Drop | IPv4 Address | | Data Item Type| Length | Add/Drop | IPv4 Address |
| | | Indicator | | | | | Indicator | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address | | IPv4 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 5 Length: 5
Add/Drop: Value indicating whether this is a new or existing address Add/Drop: Value indicating whether this is a new or existing address
(1), or a withdrawal of an address (0). (1), or a withdrawal of an address (0).
IPv4 Address: The IPv4 address of the destination or peer. IPv4 Address: The IPv4 address of the destination or peer.
8.10. IPv6 Address 7.11. IPv6 Address
The IPv6 Address data item MUST appear in the Peer Offer signal The IPv6 Address data item MAY appear in the Peer Update
(Section 7.2), and MAY appear in the Peer Update (Section 7.5), (Section 6.5), Destination Up (Section 6.9) and Destination Update
Destination Up (Section 7.9) and Destination Update (Section 7.13) (Section 6.13) signals. When included in Destination signals, this
signals. When included in Destination signals, this data item data item contains the IPv6 address of the destination. When
contains the IPv6 address of the destination. In the Peer Offer included in the Peer Update signal, this data item contains the IPv4
signal, it contains the IPv6 address of the originating peer to be address of the peer. In either case, the data item also contains an
used to establish a DLEP session. In either case, the data item also indication of whether this is a new or existing address, or is a
contains an indication of whether this is a new or existing address, deletion of a previously known address.
or is a deletion of a previously known address. When used in a Peer
Offer signal the Add/Drop Indicator MUST be 1 (i.e. Add).
The IPv6 Address data item contains the following fields: The IPv6 Address data item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 17 | Add/Drop | IPv6 Address | | Data Item Type| Length | Add/Drop | IPv6 Address |
| | | Indicator | | | | | Indicator | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Address | | IPv6 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Address | | IPv6 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Address | | IPv6 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Address | | IPv6 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 17 Length: 17
Add/Drop: Value indicating whether this is a new or existing address Add/Drop: Value indicating whether this is a new or existing address
(1), or a withdrawal of an address (0). (1), or a withdrawal of an address (0).
IPv6 Address: IPv6 Address of the destination or peer. IPv6 Address: IPv6 Address of the destination or peer.
8.11. IPv4 Attached Subnet 7.12. IPv4 Attached Subnet
The DLEP IPv4 Attached Subnet allows a device to declare that it has The DLEP IPv4 Attached Subnet allows a device to declare that it has
an IPv4 subnet (e.g., a stub network) attached. Once an IPv4 Subnet an IPv4 subnet (e.g., a stub network) attached, and MAY appear in the
has been declared on a device, the declaration can NOT be withdrawn Destination Up (Section 6.9) and Destination Update (Section 6.13)
without terminating the destination (via the Destination Down signal) signals. Once an IPv4 Subnet has been declared on a device, the
and re-issuing the Destination Up signal. declaration can NOT be withdrawn without terminating the destination
(via the Destination Down signal (Section 6.11)) and re-issuing the
Destination Up signal.
The DLEP IPv4 Attached Subnet data item data item contains the The DLEP IPv4 Attached Subnet data item contains the following
following fields: fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Data Item Type | Length = 5 | IPv4 Attached Subnet | |Data Item Type | Length | IPv4 Attached Subnet |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Attached Subnet | Subnet Mask | | IPv4 Attached Subnet | Subnet Mask |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 5 Length: 5
IPv4 Subnet: The IPv4 subnet reachable at the destination. IPv4 Subnet: The IPv4 subnet reachable at the destination.
Subnet Mask: A subnet mask (0-32) to be applied to the IPv4 subnet. Subnet Mask: A subnet mask (0-32) to be applied to the IPv4 subnet.
8.12. IPv6 Attached Subnet 7.13. IPv6 Attached Subnet
The DLEP IPv6 Attached Subnet allows a device to declare that it has The DLEP IPv6 Attached Subnet allows a device to declare that it has
an IPv6 subnet (e.g., a stub network) attached. As in the case of an IPv6 subnet (e.g., a stub network) attached, and MAY appear in the
the IPv4 attached Subnet data item above, once an IPv6 attached Destination Up (Section 6.9) and Destination Update (Section 6.13)
subnet has been declared, it can NOT be withdrawn without terminating signals. As in the case of the IPv4 attached Subnet data item above,
the destination (via Destination Down) and re-issuing the Destination once an IPv6 attached subnet has been declared, it can NOT be
Up signal. withdrawn without terminating the destination (via the Destination
Down signal (Section 6.11)) and re-issuing the Destination Up signal.
The DLEP IPv6 Attached Subnet data item data item contains the The DLEP IPv6 Attached Subnet data item contains the following
following fields: fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 17 | IPv6 Attached Subnet | | Data Item Type| Length | IPv6 Attached Subnet |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Attached Subnet | | IPv6 Attached Subnet |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Attached Subnet | | IPv6 Attached Subnet |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Attached Subnet | | IPv6 Attached Subnet |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Attached Subnet | Subnet Mask | | IPv6 Attached Subnet | Subnet Mask |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 17 Length: 17
IPv4 Subnet: The IPv6 subnet reachable at the destination. IPv4 Subnet: The IPv6 subnet reachable at the destination.
Subnet Mask: A subnet mask (0-128) to be applied to the IPv6 subnet. Subnet Mask: A subnet mask (0-128) to be applied to the IPv6 subnet.
8.13. Maximum Data Rate (Receive) 7.14. Maximum Data Rate (Receive)
The Maximum Data Rate (Receive) (MDRR) data item MUST appear in the The Maximum Data Rate (Receive) (MDRR) data item MUST appear in the
Peer Initialization ACK signal (Section 7.4), and MAY appear in the Peer Initialization ACK signal (Section 6.4), and MAY appear in the
Peer Update (Section 7.5), Destination Up (Section 7.9) and Peer Update (Section 6.5), Destination Up (Section 6.9), Destination
Destination Update (Section 7.13) signals to indicate the maximum Update (Section 6.13) and Link Characteristics ACK (Section 6.16)
theoretical data rate, in bits per second, that can be achieved while signals to indicate the maximum theoretical data rate, in bits per
receiving data on the link. second, that can be achieved while receiving data on the link.
The Maximum Data Rate (Receive) data item contains the following The Maximum Data Rate (Receive) data item contains the following
fields: fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 8 | MDRR (bps) | | Data Item Type| Length | MDRR (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MDRR (bps) | | MDRR (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MDRR (bps) | | MDRR (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 8 Length: 8
Maximum Data Rate (Receive): A 64-bit unsigned integer, representing Maximum Data Rate (Receive): A 64-bit unsigned integer, representing
the maximum theoretical data rate, in bits per second (bps), that the maximum theoretical data rate, in bits per second (bps), that
can be achieved while receiving on the link. can be achieved while receiving on the link.
8.14. Maximum Data Rate (Transmit) 7.15. Maximum Data Rate (Transmit)
The Maximum Data Rate (Transmit) (MDRT) data item MUST appear in the The Maximum Data Rate (Transmit) (MDRT) data item MUST appear in the
Peer Initialization ACK signal (Section 7.4), and MAY appear in the Peer Initialization ACK signal (Section 6.4), and MAY appear in the
Peer Update (Section 7.5), Destination Up (Section 7.9) and Peer Update (Section 6.5), Destination Up (Section 6.9), Destination
Destination Update (Section 7.13) signals to indicate the maximum Update (Section 6.13) and Link Characteristics ACK (Section 6.16)
theoretical data rate, in bits per second, that can be achieved while signals to indicate the maximum theoretical data rate, in bits per
transmitting data on the link. second, that can be achieved while transmitting data on the link.
The Maximum Data Rate (Transmit) data item contains the following The Maximum Data Rate (Transmit) data item contains the following
fields: fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 8 | MDRT (bps) | | Data Item Type| Length | MDRT (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MDRT (bps) | | MDRT (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MDRT (bps) | | MDRT (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 8 Length: 8
Maximum Data Rate (Transmit): A 64-bit unsigned integer, Maximum Data Rate (Transmit): A 64-bit unsigned integer,
representing the maximum theoretical data rate, in bits per second representing the maximum theoretical data rate, in bits per second
(bps), that can be achieved while transmitting on the link. (bps), that can be achieved while transmitting on the link.
8.15. Current Data Rate (Receive) 7.16. Current Data Rate (Receive)
The Current Data Rate (Receive) (CDRR) data item MUST appear in the The Current Data Rate (Receive) (CDRR) data item MUST appear in the
Peer Initialization ACK signal (Section 7.4), and MAY appear in the Peer Initialization ACK signal (Section 6.4), and MAY appear in the
Peer Update (Section 7.5), Destination Up (Section 7.9), Destination Peer Update (Section 6.5), Destination Up (Section 6.9), Destination
Update (Section 7.13), Link Characteristics Request (Section 7.15) Update (Section 6.13) and Link Characteristics ACK (Section 6.16)
and Link Characteristics ACK (Section 7.16) signals to indicate the signals to indicate the rate at which the link is currently operating
rate at which the link is currently operating for receiving traffic. for receiving traffic.
When used in the Link Characteristics Request signal, CDRR represents
the desired receive rate, in bits per second, on the link. When used in the Link Characteristics Request signal (Section 6.15),
CDRR represents the desired receive rate, in bits per second, on the
link.
The Current Data Rate (Receive) data item contains the following The Current Data Rate (Receive) data item contains the following
fields: fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 8 | CDRR (bps) | | Data Item Type| Length | CDRR (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CDRR (bps) | | CDRR (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CDRR (bps) | | CDRR (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 8 Length: 8
Current Data Rate (Receive): A 64-bit unsigned integer, representing Current Data Rate (Receive): A 64-bit unsigned integer, representing
the current data rate, in bits per second, that is currently be the current data rate, in bits per second, that can currently be
achieved while receiving traffic on the link. achieved while receiving traffic on the link.
If there is no distinction between current and maximum receive data If there is no distinction between current and maximum receive data
rates, current data rate receive MUST be set equal to the maximum rates, current data rate receive MUST be set equal to the maximum
data rate receive. data rate receive.
8.16. Current Data Rate (Transmit) 7.17. Current Data Rate (Transmit)
The Current Data Rate Receive (CDRT) data item MUST appear in the The Current Data Rate Transmit (CDRT) data item MUST appear in the
Peer Initialization ACK signal (Section 7.4), and MAY appear in the Peer Initialization ACK signal (Section 6.4), and MAY appear in the
Peer Update (Section 7.5), Destination Up (Section 7.9), Destination Peer Update (Section 6.5), Destination Up (Section 6.9), Destination
Update (Section 7.13), Link Characteristics Request (Section 7.15) Update (Section 6.13), and Link Characteristics ACK (Section 6.16)
and Link Characteristics ACK (Section 7.16) signals to indicate the signals to indicate the rate at which the link is currently operating
rate at which the link is currently operating for transmitting for transmitting traffic.
traffic. When used in the Link Characteristics Request signal, CDRT
represents the desired transmit rate, in bits per second, on the When used in the Link Characteristics Request signal (Section 6.15),
CDRT represents the desired transmit rate, in bits per second, on the
link. link.
The Current Data Rate (Transmit) data item contains the following The Current Data Rate (Transmit) data item contains the following
fields: fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 8 | CDRT (bps) | | Data Item Type| Length | CDRT (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CDRT (bps) | | CDRT (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CDRT (bps) | | CDRT (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 8 Length: 8
Current Data Rate (Transmit): A 64-bit unsigned integer, Current Data Rate (Transmit): A 64-bit unsigned integer,
representing the current data rate, in bits per second, that is representing the current data rate, in bits per second, that can
currently be achieved while transmitting traffic on the link. currently be achieved while transmitting traffic on the link.
If there is no distinction between current and maximum transmit data If there is no distinction between current and maximum transmit data
rates, current data rate transmit MUST be set equal to the maximum rates, current data rate transmit MUST be set equal to the maximum
data rate transmit. data rate transmit.
8.17. Latency 7.18. Latency
The Latency data item data item MUST appear in the Peer The Latency data item data item MUST appear in the Peer
Initialization ACK signal (Section 7.4), and MAY appear in the Peer Initialization ACK signal (Section 6.4), and MAY appear in the Peer
Update (Section 7.5), Destination Up (Section 7.9), Destination Update (Section 6.5), Destination Up (Section 6.9), Destination
Update (Section 7.13), Link Characteristics Request (Section 7.15) Update (Section 6.13), and Link Characteristics ACK (Section 6.16)
and Link Characteristics ACK (Section 7.16) signals to indicate the signals to indicate the amount of latency, in microseconds, on the
amount of latency, in microseconds, on the link, or in the case of link.
the Link Characteristics Request, to indicate the maximum latency
required on the link. When used in the Link Characteristics Request signal (Section 6.15),
Latency represents the maximum latency desired on the link.
The Latency value is reported as delay. The calculation of latency The Latency value is reported as delay. The calculation of latency
is implementation dependent. For example, the latency may be a is implementation dependent. For example, the latency may be a
running average calculated from the internal queuing. running average calculated from the internal queuing.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 4 | Latency in microseconds | | Data Item Type| Length | Latency |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Latency (cont.) microsecs | | Latency (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 4 Length: 4
Latency: A 32-bit unsigned value, representing the transmission Latency: A 32-bit unsigned integer, representing the transmission
delay that a packet encounters as it is transmitted over the link. delay, in microseconds, that a packet encounters as it is
transmitted over the link.
8.18. Resources (Receive) 7.19. Resources (Receive)
The Resources (Receive) (RESR) data item MAY appear in the Peer The Resources (Receive) (RESR) data item MAY appear in the Peer
Initialization ACK signal (Section 7.4), Peer Update (Section 7.5), Initialization ACK signal (Section 6.4), Peer Update (Section 6.5),
Destination Up (Section 7.9), Destination Update (Section 7.13) and Destination Up (Section 6.9), Destination Update (Section 6.13) and
Link Characteristics ACK (Section 7.16) signals to indicate the Link Characteristics ACK (Section 6.16) signals to indicate the
amount of recources for reception (with 0 meaning 'no resources amount of resources for reception (with 0 meaning 'no resources
available', and 100 meaning 'all resources available') at the available', and 100 meaning 'all resources available') at the
destination. The list of resources that might be considered is destination. The list of resources that might be considered is
beyond the scope of this document, and is left to implementations to beyond the scope of this document, and is left to implementations to
decide. decide.
The Resources (Receive) data item contains the following fields: The Resources (Receive) data item contains the following fields:
0 1 2 0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 1 | RESR | | Data Item Type| Length | RESR |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 1 Length: 1
Resources (Receive): A percentage, 0-100, representing the amount of Resources (Receive): An 8-bit integer percentage, 0-100,
resources allocated to receiving data. representing the amount of resources allocated to receiving data.
If a device cannot calculate RESR, this data item SHOULD NOT be If a device cannot calculate RESR, this data item SHOULD NOT be
issued. issued.
8.19. Resources (Transmit) 7.20. Resources (Transmit)
The Resources (Receive) (RESR) data item MAY appear in the Peer The Resources (Transmit) (REST) data item MAY appear in the Peer
Initialization ACK signal (Section 7.4), Peer Update (Section 7.5), Initialization ACK signal (Section 6.4), Peer Update (Section 6.5),
Destination Up (Section 7.9), Destination Update (Section 7.13) and Destination Up (Section 6.9), Destination Update (Section 6.13) and
Link Characteristics ACK (Section 7.16) signals to indicate the Link Characteristics ACK (Section 6.16) signals to indicate the
amount of recources for transmission (with 0 meaning 'no resources amount of resources for transmission (with 0 meaning 'no resources
available', and 100 meaning 'all resources available') at the available', and 100 meaning 'all resources available') at the
destination. The list of resources that might be considered is destination. The list of resources that might be considered is
beyond the scope of this document, and is left to implementations to beyond the scope of this document, and is left to implementations to
decide. decide.
The Resources (Transmit) data item contains the following fields: The Resources (Transmit) data item contains the following fields:
0 1 2 0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 1 | REST | | Data Item Type| Length | REST |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 1 Length: 1
Resources (Transmit): A percentage, 0-100, representing the amount Resources (Transmit): An 8-bit integer percentage, 0-100,
of resources allocated to transmitting data. representing the amount of resources allocated to transmitting
data.
If a device cannot calculate REST, this data item SHOULD NOT be If a device cannot calculate REST, this data item SHOULD NOT be
issued. issued.
8.20. Relative Link Quality (Receive) 7.21. Relative Link Quality (Receive)
The Relative Link Quality (Receive) (RLQR) data item MAY appear in The Relative Link Quality (Receive) (RLQR) data item MAY appear in
the Peer Initialization ACK signal (Section 7.4), Peer Update the Peer Initialization ACK signal (Section 6.4), Peer Update
(Section 7.5), Destination Up (Section 7.9), Destination Update (Section 6.5), Destination Up (Section 6.9), Destination Update
(Section 7.13) and Link Characteristics ACK (Section 7.16) signals to (Section 6.13) and Link Characteristics ACK (Section 6.16) signals to
indicate the quality of the link for receiving data as calculated by indicate the quality of the link for receiving data.
the originating peer.
The Relative Link Quality (Receive) data item contains the following The Relative Link Quality (Receive) data item contains the following
fields: fields:
0 1 2 0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 1 | RLQR | | Data Item Type| Length | RLQR |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 1 Length: 1
Relative Link Quality (Receive): A non-dimensional integer, 1-100, Relative Link Quality (Receive): A non-dimensional 8-bit integer,
representing relative link quality. A value of 100 represents a 1-100, representing relative link quality. A value of 100
link of the highest quality. represents a link of the highest quality.
If a device cannot calculate the RLQR, this data item SHOULD NOT be If a device cannot calculate the RLQR, this data item SHOULD NOT be
issued. issued.
8.21. Relative Link Quality (Transmit) 7.22. Relative Link Quality (Transmit)
The Relative Link Quality (Transmit) (RLQT) data item MAY appear in The Relative Link Quality (Transmit) (RLQT) data item MAY appear in
the Peer Initialization ACK signal (Section 7.4), Peer Update the Peer Initialization ACK signal (Section 6.4), Peer Update
(Section 7.5), Destination Up (Section 7.9), Destination Update (Section 6.5), Destination Up (Section 6.9), Destination Update
(Section 7.13) and Link Characteristics ACK (Section 7.16) signals to (Section 6.13) and Link Characteristics ACK (Section 6.16) signals to
indicate the quality of the link for transmitting data as calculated indicate the quality of the link for transmitting data.
by the originating peer.
The Relative Link Quality (Transmit) data item contains the following The Relative Link Quality (Transmit) data item contains the following
fields: fields:
0 1 2 0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 1 | RLQT | | Data Item Type| Length | RLQT |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 1 Length: 1
Relative Link Quality (Transmit): A non-dimensional integer, 1-100, Relative Link Quality (Transmit): A non-dimensional 8-bit integer,
representing relative link quality. A value of 100 represents a 1-100, representing relative link quality. A value of 100
link of the highest quality. represents a link of the highest quality.
If a device cannot calculate the RLQT, this data item SHOULD NOT be If a device cannot calculate the RLQT, this data item SHOULD NOT be
issued. issued.
8.22. Link Characteristics ACK Timer 7.23. Link Characteristics ACK Timer
The Link Characteristics ACK Timer data item MAY appear in the Link The Link Characteristics ACK Timer data item MAY appear in the Link
Characterisitics Request signal (Section 7.15) to indicate the Characteristics Request signal (Section 6.15) to indicate the desired
desired number of seconds to the sender will wait for a response to number of seconds to the sender will wait for a response to the
the request. If this data item is omitted, implementations request. If this data item is omitted, implementations supporting
supporting the Link Characteristics Request SHOULD choose a default the Link Characteristics Request SHOULD choose a default value.
value.
The Link Characteristics ACK Timer data item contains the following The Link Characteristics ACK Timer data item contains the following
fields: fields:
0 1 2 0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 1 | Interval | | Data Item Type| Length | Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 1 Length: 1
Interval: 0 = Do NOT use timeouts for Link Characteristics requests Interval: 0 = Do NOT use timeouts for this Link Characteristics
on this router/modem session. Non-zero = Interval, in seconds, to request. Non-zero = Interval, in seconds, to wait before
wait before considering a Link Characteristics Request has been considering this Link Characteristics Request has been lost.
lost.
9. Credit-Windowing 8. Credit-Windowing
DLEP includes an OPTIONAL credit-windowing scheme analogous to the DLEP includes an OPTIONAL Protocol Extension for a credit-windowing
one documented in [RFC5578]. In this scheme, traffic between the scheme analogous to the one documented in [RFC5578]. In this scheme,
router and modem is treated as two unidirectional windows. This traffic between the router and modem is treated as two unidirectional
document identifies these windows as the 'Modem Receive Window', or windows. This document identifies these windows as the 'Modem
MRW, and the 'Router Receive Window', or RRW. Receive Window' (MRW), and the 'Router Receive Window' (RRW).
If the OPTIONAL credit-windowing scheme is used, credits MUST be If the OPTIONAL credit-windowing extension is used, credits MUST be
granted by the receiver on a given window - that is, on the 'Modem granted by the receiver on a given window - that is, on the 'Modem
Receive Window' (MRW), the modem is responsible for granting credits Receive Window' (MRW), the modem is responsible for granting credits
to the router, allowing it (the router) to send data to the modem. to the router, allowing it (the router) to send data to the modem.
Likewise, the router is responsible for granting credits on the RRW, Likewise, the router is responsible for granting credits on the RRW,
which allows the modem to send data to the router. which allows the modem to send data to the router.
DLEP expresses all credit data in number of octets. The total number Credits are managed on a destination-specific basis; that is,
of credits on a window, and the increment to add to a grant, are separate credit counts are maintained for each destination requiring
always expressed as a 64-bit unsigned integer quantity. the service. Credits do not apply to the DLEP session that exists
If used, credits are managed on a neighbor-specific basis; that is,
separate credit counts are maintained for each neighbor requiring the
service. Credits do not apply to the DLEP session that exists
between routers and modems. between routers and modems.
If a peer is able to support the OPTIONAL credit-windowing scheme If a peer is able to support the OPTIONAL credit-windowing extension
then it MUST include a Extensions Supported data item (Section 8.6) then it MUST include a Extensions Supported data item (Section 7.7)
including the value DLEP_EXT_CREDITS (value TBD) in the appropriate including the value DLEP_EXT_CREDITS (value TBD) in the appropriate
Peer Initialization or Peer Initialization ACK signal. Peer Initialization or Peer Initialization ACK signal.
9.1. Credit-Windowing Signals 8.1. Credit-Windowing Signals
The credit-windowing scheme introduces no additional DLEP signals. The credit-windowing extension introduces no additional DLEP signals.
However, if a peer has advertised during session initialization that However, if a peer has advertised during session initialization that
it supports the credit-windowing scheme then the following DLEP it supports the credit-windowing extension then the following DLEP
signals may contain additional credit-windowing data items: signals MAY contain additional credit-windowing data items:
9.1.1. Destination Up Signal 8.1.1. Destination Up Signal
The Destination Up signal MAY contain one of each of the following The Destination Up signal MAY contain one of each of the following
data items: data items:
o Credit Grant (Section 9.2.2) o Credit Grant (Section 8.2.1)
9.1.2. Destination Up ACK Signal If the Destination Up signal does not contain the Credit Grant data
item, credits MUST NOT be used for that destination.
The Destination Up ACK signal MAY contain one of each of the 8.1.2. Destination Up ACK Signal
following data items:
o Credit Window Status (Section 9.2.1) If the corresponding Destination Up signal contained the Credit Grant
data item, the Destination Up ACK signal MUST contain one of each of
the following data items:
9.1.3. Destination Update Signal o Credit Window Status (Section 8.2.2)
The Destination Update signal MAY contain one of each of the 8.1.3. Destination Update Signal
following data items:
o Credit Window Status (Section 9.2.1) If the corresponding Destination Up signal contained the Credit Grant
data item, the Destination Update signal MUST contain one of each of
the following data items:
o Credit Grant (Section 9.2.2) o Credit Window Status (Section 8.2.2)
o Credit Request (Section 9.2.3) If the corresponding Destination Up signal contained the Credit Grant
data item, the Destination Update signal MAY contain one of each of
the following data items:
9.2. Credit-Windowing Data Items o Credit Grant (Section 8.2.1)
The credit-windowing scheme introduces 3 additional data items. If a o Credit Request (Section 8.2.3)
peer has advertised during session initialization that it supports
the credit-windowing scheme then it MUST correctly process the 8.2. Credit-Windowing Data Items
following data items without error.
The credit-windowing extension introduces 3 additional data items.
If a peer has advertised during session initialization that it
supports the credit-windowing extension then it MUST correctly
process the following data items without error.
+------------+-----------------------+----------------+ +------------+-----------------------+----------------+
| Data Item | Description | Section | | Data Item | Description | Section |
+------------+-----------------------+----------------+ +------------+-----------------------+----------------+
| TBD | Credit Window Status | Section 9.2.1 | | TBD | Credit Grant | Section 8.2.1 |
| TBD | Credit Grant | Section 9.2.2 | | TBD | Credit Window Status | Section 8.2.2 |
| TBD | Credit Request | Section 9.2.3 | | TBD | Credit Request | Section 8.2.3 |
+------------+-----------------------+----------------+ +------------+-----------------------+----------------+
9.2.1. Credit Window Status 8.2.1. Credit Grant
If the credit-window scheme is supported by the DLEP participants
(both the router and the modem), the Credit Window Status data item
MUST be sent by the participant receiving a Credit Grant for a given
destination.
The Credit Window Status data item contains the following fields:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 16 | Modem Receive Window Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Modem Receive Window Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Modem Receive Window Value | Router Receive Window Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Router Receive Window Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Router Receive Window Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD
Length: 16
Modem Receive Window Value: A 64-bit unsigned integer, indicating
the current (or initial) number of credits available on the Modem
Receive Window.
Router Receive Window Value: A 64-bit unsigned integer, indicating
the current (or initial) number of credits available on the Router
Receive Window.
9.2.2. Credit Grant
The Credit Grant data item is sent from a DLEP participant to grant The Credit Grant data item is sent from a DLEP participant to grant
an increment to credits on a window. The Credit Grant data item MAY an increment to credits on a window. The Credit Grant data item MAY
appear in the Destination Up (Section 7.9) or Destination Update appear in the Destination Up (Section 6.9) and Destination Update
(Section 7.13) signals. The value in a Credit Grant data item (Section 6.13) signals. The value in a Credit Grant data item
represents an increment to be added to any existing credits available represents an increment to be added to any existing credits available
on the window. Upon successful receipt and processing of a Credit on the window. Upon successful receipt and processing of a Credit
Grant data item, the receiver MUST respond with a signal containing a Grant data item, the receiver MUST respond with a signal containing a
Credit Window Status data item to report the updated aggregate values Credit Window Status data item to report the updated aggregate values
for synchronization purposes. for synchronization purposes, and if initializing a new credit
window, granting initial credits.
In the Destination Up signal, when credits are desired, the In the Destination Up signal, when credits are desired, the
originating peer MUST set the initial credit value of the window it originating peer MUST set the initial credit value of the window it
controls (i.e., the Modem Receive Window, or Router Receive Window) controls (i.e., the Modem Receive Window, or Router Receive Window)
to an initial, non-zero value. If the receiver of a Destination Up to an initial, non-zero value. If the receiver of a Destination Up
signal with a Credit Grant data item supports credits, the receiver signal with a Credit Grant data item supports credits, the receiver
MUST either reject the use of credits, via a Destination Up ACK MUST either reject the use of credits for this destination, via a
response containing a Status data item (Section 8.2) with a status Destination Up ACK response containing a Status data item
code of 'Request Denied', or set the initial value from the data (Section 7.2) with a status code of 'Request Denied', or set the
contained in the Credit Window Status data item. If the initial value from the data contained in the Credit Window Status
initialization completes successfully, the receiver MUST respond to data item. If the initialization completes successfully, the
the Destination Up signal with a Destination Up ACK signal that receiver MUST respond to the Destination Up signal with a Destination
contains a Credit Window Status data item, initializing its receive Up ACK signal that contains a Credit Window Status data item,
window. initializing its receive window.
The Credit Grant data item contains the following fields: The Credit Grant data item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 8 | Credit Increment | | Data Item Type| Length | Credit Increment |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Credit Increment | | Credit Increment |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Credit Increment | | Credit Increment |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 8 Length: 8
Reserved: A 64-bit unsigned integer representing the additional Reserved: A 64-bit unsigned integer representing the additional
credits to be assigned to the credit window. credits to be assigned to the credit window.
Since credits can only be granted by the receiver on a window, the Since credits can only be granted by the receiver on a window, the
applicable credit window (either the MRW or the RRW) is derived from applicable credit window (either the MRW or the RRW) is derived from
the sender of the grant. The Credit Increment MUST NOT cause the the sender of the grant. The Credit Increment MUST NOT cause the
window to overflow; if this condition occurs, implementations MUST window to overflow; if this condition occurs, implementations MUST
set the credit window to the maximum value contained in a 64-bit set the credit window to the maximum value contained in a 64-bit
quantity. quantity.
9.2.3. Credit Request 8.2.2. Credit Window Status
If the credit-window extension is supported by the DLEP participants
(both the router and the modem), the Credit Window Status data item
MUST be sent by the participant receiving a Credit Grant for a given
destination.
The Credit Window Status data item contains the following fields:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length | Modem Receive Window Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Modem Receive Window Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Modem Receive Window Value | Router Receive Window Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Router Receive Window Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Router Receive Window Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD
Length: 16
Modem Receive Window Value: A 64-bit unsigned integer, indicating
the current number of credits available on the Modem Receive
Window, for the destination referred to by the signal.
Router Receive Window Value: A 64-bit unsigned integer, indicating
the current number of credits available on the Router Receive
Window, for the destination referred to by the signal.
8.2.3. Credit Request
The Credit Request data item MAY be sent from either DLEP The Credit Request data item MAY be sent from either DLEP
participant, via the Destination Update signal (Section 7.13), to participant, via the Destination Update signal (Section 6.13), to
indicate the desire for the partner to grant additional credits in indicate the desire for the partner to grant additional credits in
order for data transfer to proceed on the session. If the order for data transfer to proceed on the session. If the
corresponding Destination Up signal (Section 7.9) for this session corresponding Destination Up signal (Section 6.9) for this session
did NOT contain a Credit Window Status data item, indicating that did NOT contain a Credit Window Status data item, indicating that
credits are to be used on the session, then the Credit Request data credits are to be used on the session, then the Credit Request data
item MUST be rejected by the receiver via a Destination Update ACK item MUST be silently dropped by the receiver.
signal containing a Status data item (Section 8.2) with status code
'Request Denied'.
The Credit Request data item contains the following fields: The Credit Request data item contains the following fields:
0 1 2 0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type| Length = 1 | Reserved, MUST| | Data Item Type| Length | Reserved, MUST|
| | | be set to 0 | | | | be set to 0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBD Data Item Type: TBD
Length: 1 Length: 1
Reserved: This field is currently unused and MUST be set to 0. Reserved: This field is currently unused and MUST be set to 0.
10. Security Considerations 9. Security Considerations
The protocol does not contain any mechanisms for security (e.g., The protocol does not contain any mechanisms for security (e.g.,
authentication or encryption). The protocol assumes that any authentication or encryption). The protocol assumes that any
security would be implemented in the underlying transport (for security would be implemented in the underlying transport (for
example, by use of DTLS or some other mechanism), and is therefore example, by use of DTLS or some other mechanism), and is therefore
outside the scope of this document. outside the scope of this document.
11. IANA Considerations 10. IANA Considerations
This section specifies requests to IANA. This section specifies requests to IANA.
11.1. Registrations 10.1. Registrations
This specification defines: This specification defines:
o A new repository for DLEP signals, with sixteen values currently o A new repository for DLEP signals, with sixteen values currently
assigned. assigned.
o Reservation of numbering space for Experimental DLEP signals. o Reservation of numbering space for Experimental DLEP signals.
o A new repository for DLEP data items, with twenty-three values o A new repository for DLEP data items, with twenty-six values
currently assigned. currently assigned.
o Reservation of numbering space in the data items repository for o Reservation of numbering space in the data items repository for
experimental data items. experimental data items.
o A new repository for DLEP status codes. o A new repository for DLEP status codes, with seven currently
assigned.
o A new repository for DLEP extensions, with one value currently o A new repository for DLEP extensions, with one value currently
assigned. assigned.
o A request for allocation of a well-known port for DLEP o A request for allocation of a well-known port for DLEP TCP and UDP
communication. communication.
o A request for allocation of a multicast address for DLEP o A request for allocation of a multicast IP address for DLEP
discovery. discovery.
11.2. Expert Review: Evaluation Guidelines 10.2. Expert Review: Evaluation Guidelines
No additional guidelines for expert review are anticipated. No additional guidelines for expert review are anticipated.
11.3. Signal Type Registration 10.3. Signal Type Registration
A new repository must be created with the values of the DLEP signals. A new repository must be created with the values of the DLEP signals.
All signal values are in the range [0..255]. All signal values are in the range [0..255].
Valid signals are: Valid signals are:
o Peer Discovery o Peer Discovery
o Peer Offer o Peer Offer
skipping to change at page 51, line 47 skipping to change at page 53, line 4
o Destination Up ACK o Destination Up ACK
o Destination Down o Destination Down
o Destination Down ACK o Destination Down ACK
o Destination Update o Destination Update
o Heartbeat o Heartbeat
o Link Characteristics Request o Link Characteristics Request
o Link Characteristics ACK o Link Characteristics ACK
It is also requested that the repository contain space for It is also requested that the repository contain space for
experimental signal types. experimental signal types.
11.4. DLEP Data Item Registrations 10.4. DLEP Data Item Registrations
A new repository for DLEP data items must be created. A new repository for DLEP data items must be created.
All data item values are in the range [0..255]. All data item values are in the range [0..255].
Valid data items are: Valid data items are:
o DLEP Version o DLEP Version
o Status o Status
o DLEP Port o IPv4 Connection Point
o IPv6 Connection Point
o Peer Type o Peer Type
o Heartbeat Interval o Heartbeat Interval
o Extensions Supported o Extensions Supported
o Experimental Definition o Experimental Definition
o MAC Address o MAC Address
skipping to change at page 52, line 46 skipping to change at page 54, line 4
o IPv6 Attached Subnet o IPv6 Attached Subnet
o Maximum Data Rate (Receive) o Maximum Data Rate (Receive)
o Maximum Data Rate (Transmit) o Maximum Data Rate (Transmit)
o Current Data Rate (Receive) o Current Data Rate (Receive)
o Current Data Rate (Transmit) o Current Data Rate (Transmit)
o Latency o Latency
o Resources (Receive) o Resources (Receive)
o Resources (Transmit) o Resources (Transmit)
o Relative Link Quality (Receive) o Relative Link Quality (Receive)
o Relative Link Quality (Transmit) o Relative Link Quality (Transmit)
o Link Characteristics ACK Timer o Link Characteristics ACK Timer
o Credit Window Status o Credit Window Status
o Credit Grant o Credit Grant
o Credit Request o Credit Request
It is also requested that the registry allocation contain space for It is also requested that the registry allocation contain space for
experimental data items. experimental data items.
11.5. DLEP Status Code Registrations 10.5. DLEP Status Code Registrations
A new repository for DLEP status codes must be created. A new repository for DLEP status codes must be created.
All status codes are in the range [0..255]. All status codes are in the range [0..255].
Valid status codes are: Valid status codes are:
o Success (value 0) o Success (value 0)
o Unknown Signal o Unknown Signal
o Invalid Signal o Invalid Data
o Unexpected Signal o Unexpected Signal
o Request Denied o Request Denied
o Timed Out o Timed Out
11.6. DLEP Extensions Registrations o Invalid Destination
10.6. DLEP Extensions Registrations
A new repository for DLEP extensions must be created. A new repository for DLEP extensions must be created.
All extension values are in the range [0..255]. All extension values are in the range [0..255].
Valid extensions are: Valid extensions are:
o DLEP_EXT_CREDITS - Credit windowing o DLEP_EXT_CREDITS - Credit windowing
11.7. DLEP Well-known Port 10.7. DLEP Well-known Port
It is requested that IANA allocate a well-known port number for DLEP It is requested that IANA allocate a well-known port number for DLEP
communication. communication.
11.8. DLEP Multicast Address 10.8. DLEP Multicast Address
It is requested that IANA allocate a multicast address for DLEP It is requested that IANA allocate a multicast address for DLEP
discovery signals. discovery signals.
12. Acknowledgements 11. Acknowledgements
The authors would like to acknowledge and thank the members of the The authors would like to acknowledge and thank the members of the
DLEP design team, who have provided invaluable insight. The members DLEP design team, who have provided invaluable insight. The members
of the design team are: Teco Boot, Bow-Nan Cheng, John Dowdell, and of the design team are: Teco Boot, Bow-Nan Cheng, John Dowdell, and
Henning Rogge. Henning Rogge.
The authors would also like to acknowledge the influence and The authors would also like to acknowledge the influence and
contributions of Greg Harrison, Chris Olsen, Martin Duke, Subir Das, contributions of Greg Harrison, Chris Olsen, Martin Duke, Subir Das,
Jaewon Kang, Vikram Kaul, and Nelson Powell. Jaewon Kang, Vikram Kaul, Nelson Powell and Victoria Mercieca.
13. References 12. References
13.1. Normative References 12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5578] Berry, B., Ratliff, S., Paradise, E., Kaiser, T., and M. [RFC5578] Berry, B., Ratliff, S., Paradise, E., Kaiser, T., and M.
Adams, "PPP over Ethernet (PPPoE) Extensions for Credit Adams, "PPP over Ethernet (PPPoE) Extensions for Credit
Flow and Link Metrics", RFC 5578, February 2010. Flow and Link Metrics", RFC 5578, February 2010.
13.2. Informative References 12.2. Informative References
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008. (TLS) Protocol Version 1.2", RFC 5246, August 2008.
Appendix A. Peer Level Signal Flows Appendix A. Peer Level Signal Flows
_NB_ The following diagrams are possibly out of date. If there is a A.1. Discovery
discepancy with the text, then the text is correct.
A.1. Router Device Restarts Discovery
Router Modem Signal Description Router Modem Signal Description
==================================================================== ========================================================================
<--------Peer Offer------------ Modem detects a problem, sends
w/ Non-zero Status TLV Peer Offer w/Status TLV indicating
the error.
Router accepts failure, restarts
discovery process.
| Router initiates discovery, starts
| a timer, send Peer Discovery
|-------Peer Discovery---->|| signal.
<--------Peer Offer------------ Modem accepts, sends Peer Offer ~ ~ ~ ~ ~ ~ ~ Router discovery timer expires
w/Zero Status TLV indicating without receiving Peer Offer.
success.
Discovery completed. | Router sends another Peer
|-------Peer Discovery---------->| Discovery signal.
|
| Modem receives Peer Discovery
| signal.
|
| Modem sends Peer Offer with
|<--------Peer Offer-------------| Connection Point information.
:
: Router MAY cancel discovery timer
: and stop sending Peer Discovery
: signals.
A.2. Router Device Detects Peer Offer Timeout A.2. Session Initialization
Router Modem Signal Description Router Modem Signal Description
==================================================================== ========================================================================
--------Peer Discovery--------> Router initiates discovery, starts
a guard timer.
Router guard timer expires. Router
restarts discovery process.
--------Peer Discovery--------> Router initiates discovery, starts
a guard timer.
<--------Peer Offer------------ Modem accepts, sends Peer Offer
w/Zero Status TLV indicating
success.
Discovery completed.
A.3. Router Peer Offer Lost
Router Modem Signal Description
====================================================================
<-------Peer Discovery--------- Modem initiates discovery, starts
a guard timer.
---------Peer Offer-------|| Router offers availability
Modem times out on Peer Offer,
restarts discovery process.
<-------Peer Discovery--------- Modem initiates discovery
---------Peer Offer-----------> Router detects subsequent
discovery, internally terminates
the previous, accepts the new
association, sends Peer Offer
w/Status TLV indicating success.
Discovery completed.
A.4. Discovery Success
Router Modem Signal Description
====================================================================
<-------Peer Discovery--------- Modem initiates discovery
---------Peer Offer-----------> Router offers availability
<-----Peer Initialization------ Modem Connects on TCP Port
<------Peer Heartbeat----------
-------Peer Heartbeat--------->
<==============================> Signal flow about destinations
(i.e. Destination Up, Destination
Down, Destination update)
<-------Peer Heartbeat---------
-------Peer Heartbeat--------->
--------Peer Term Req---------> Terminate Request
<--------Peer Term Res--------- Terminate Response | Router connects to discovered or
| pre-configured Modem Connection
|---------TCP connect----------> Point.
|
| Router sends Peer Initialization
|-------Peer Initialization----->| signal.
|
| Modem receives Peer Initialization
| signal.
|
| Modem sends Peer Initialization
| ACK, with compatible extensions,
|<----Peer Initialization ACK----| and Success status data item.
| |
|<<============================>>| Session established. Heartbeats
: : begin.
A.5. Router Detects a Heartbeat timeout A.3. Session Initialization - Refused
Router Modem Signal Description Router Modem Signal Description
==================================================================== ========================================================================
<-------Peer Heartbeat---------
-------Peer Heartbeat--------->
||---Peer Heartbeat---------
~ ~ ~ ~ ~ ~ ~ | Router connects to discovered or
| pre-configured Modem Connection
|---------TCP connect----------> Point.
|
| Router sends Peer Initialization
|-------Peer Initialization----->| signal.
|
| Modem receives Peer Initialization
| signal, and will not support the
| advertised version, experiment or
| extensions.
|
| Modem sends Peer Initialization
| ACK, with 'Request Denied' status
|<----Peer Initialization ACK----| data item.
| |
| <---- TCP shutdown (send)-----| Modem closes TCP connection.
|
| Router receives negative Peer
| Initialization ACK, closes
|---------TCP close-----------> TCP connection.
|
||------------------------------|| Session not started.
-------Peer Heartbeat---------> A.4. Router Changes IP Addresses
||---Peer Heartbeat--------- Router Modem Signal Description
Router Heartbeat Timer expires, ========================================================================
detects missing heartbeats. Router
takes down all destination
sessions and terminates the Peer
association.
| Router sends Peer Update signal to
|--------Peer Update------------>| announce change of IP address
|
| Modem receives Peer Update signal
| and updates internal state.
|
|<-------Peer Update ACK---------| Modem sends Peer Update ACK.
Modem takes down all destination A.5. Modem Changes Session-wide Metrics
sessions, then acknowledges the Router Modem Signal Description
Peer Terminate ========================================================================
<----Peer Terminate ACK--------- Peer Terminate ACK | Modem sends Peer Update signal to
| announce change of modem-wide
|<--------Peer Update------------| metrics
|
| Router receives Peer Update signal
| and updates internal state.
|
|-------Peer Update ACK--------->| Router sends Peer Update ACK.
A.6. Modem Detects a Heartbeat timeout A.6. Router Terminates Session
Router Modem Signal Description
====================================================================
<-------Peer Heartbeat--------- Router Modem Signal Description
========================================================================
-------Peer Heartbeat------|| | Router sends Peer Termination
|-------Peer Termination-------->| signal with Status data item.
| |
|-------TCP shutdown (send)---> | Router stops sending signals.
|
| Modem receives Peer Termination,
| stops counting received heartbeats
| and stops sending heartbeats.
|
| Modem sends Peer Termination ACK
|<-----Peer Termination ACK------| with Status 'Success'.
| |
| <----TCP shutdown (send)------| Modem stops sending signals.
|
||------------------------------|| Session terminated.
<-------Peer Heartbeat--------- A.7. Modem Terminates Session
Router Modem Signal Description
========================================================================
~ ~ ~ ~ ~ ~ ~ | Modem sends Peer Termination
|<------Peer Termination---------| signal with Status data item.
| |
| <----TCP shutdown (send)------| Modem stops sending signals.
|
| Router receives Peer Termination,
| stops counting received heartbeats
| and stops sending heartbeats.
|
| Router sends Peer Termination ACK
|------Peer Termination ACK----->| with Status 'Success'.
| |
|-------TCP shutdown (send)---> | Router stops sending signals.
|
||------------------------------|| Session terminated.
-------Peer Heartbeat------|| A.8. Session Heartbeats
Router Modem Signal Description
========================================================================
<-------Peer Heartbeat--------- |----------Heartbeat------------>| Router sends heartbeat signal
Modem Heartbeat Timer expires, |
detects missing heartbeats. Modem | Modem resets heartbeats missed
takes down all destination | counter.
sessions
<-------Peer Terminate-------- Peer Terminate Request ~ ~ ~ ~ ~ ~ ~
Router takes down all destination |----------[Any signal]--------->| When the Modem receives any signal
sessions, then acknowledges the | from the Router.
Peer Terminate |
| Modem resets heartbeats missed
| counter.
------Peer Terminate ACK-----> Peer Terminate ACK ~ ~ ~ ~ ~ ~ ~
A.7. Peer Terminate (from Modem) Lost |<---------Heartbeat-------------| Modem sends heartbeat signal
|
| Router resets heartbeats missed
| counter.
Router Modem Signal Description ~ ~ ~ ~ ~ ~ ~
====================================================================
||------Peer Terminate-------- Modem Peer Terminate Request |<---------[Any signal]----------| When the Router receives any
| signal from the Modem.
|
| Modem resets heartbeats missed
| counter.
Router Heartbeat times out, A.9. Router Detects a Heartbeat timeout
terminates association.
--------Peer Terminate-------> Router Peer Terminate Router Modem Signal Description
========================================================================
<-----Peer Terminate ACK------ Modem sends Peer Terminate ACK ||<----------------------| Router misses a heartbeat
A.8. Peer Terminate (from Router) Lost | ||<----------------------| Router misses too many heartbeats
Router Modem Signal Description |
==================================================================== |
|-------Peer Termination-------->| Router sends Peer Termination
| signal with 'Timeout' Status
| data item.
:
: Termination proceeds as above.
-------Peer Terminate--------> Router Peer Terminate Request A.10. Modem Detects a Heartbeat timeout
Modem HB times out, Router Modem Signal Description
terminates association. ========================================================================
<------Peer Terminate-------- Modem Peer Terminate |---------------------->|| Modem misses a heartbeat
------Peer Terminate ACK-----> Peer Terminate ACK |---------------------->|| | Modem misses too many heartbeats
|
|
|<-------Peer Termination--------| Modem sends Peer Termination
| signal with 'Timeout' Status
| data item.
:
: Termination proceeds as above.
Appendix B. Destination Specific Signal Flows Appendix B. Destination Specific Signal Flows
B.1. Modem Destination Up Lost B.1. Common Destination Signaling
Router Modem Signal Description
====================================================================
||-----Destination Up ------------ Modem sends Destination Up
Modem timesout on ACK
<------Destination Up ------------ Modem sends Destination Up
------Destination Up ACK---------> Router accepts the destination
session
<------Destination Update--------- Modem Destination Metrics
. . . . . . . .
<------Destination Update--------- Modem Destination Metrics
B.2. Router Detects Duplicate Destination Ups
Router Modem Signal Description
====================================================================
<------Destination Up ------------ Modem sends Destination Up
------Destination Up ACK-------|| Router accepts the destination
session
Modem timesout on ACK
<------Destination Up ------------ Modem resends Destination Up
Router detects duplicate
Destination, takes down the
previous, accepts the new
Destination.
------Destination Up ACK---------> Router accepts the destination
session
<------Destination Update--------- Modem Destination Metrics
. . . . . . . .
<------Destination Update--------- Modem Destination Metrics
B.3. Destination Up, No Layer 3 Addresses
Router Modem Signal Description
====================================================================
<------Destination Up ------------ Modem sends Destination Up
------Destination Up ACK---------> Router accepts the destination
session
Router ARPs for IPv4 if defined.
Router drives ND for IPv6 if
defined.
<------Destination Update--------- Modem Destination Metrics
. . . . . . . .
<------Destination Update--------- Modem Destination Metrics
B.4. Destination Up with IPv4, No IPv6
Router Modem Signal Description
====================================================================
<------Destination Up ------------ Modem sends Destination Up with
the IPv4 TLV
------Destination Up ACK---------> Router accepts the destination
session
Router drives ND for IPv6 if
defined.
<------Destination Update--------- Modem Destination Metrics
. . . . . . . .
<------Destination Update--------- Modem Destination Metrics
B.5. Destination Up with IPv4 and IPv6
Router Modem Signal Description
====================================================================
<------Destination Up ------------ Modem sends Destination Up with
the IPv4 and IPv6 TLVs
------Destination Up ACK---------> Router accepts the destination
session
<------Destination Update--------- Modem Destination Metrics Router Modem Signal Description
. . . . . . . . ========================================================================
B.6. Destination Session Success | Modem detects a new logical
Router Modem Signal Description | destination is reachable, and
==================================================================== |<-------Destination Up----------| sends Destination Up signal.
|
|--------Destination Up ACK----->| Router sends Destination Up ACK.
---------Peer Offer-----------> Router offers availability ~ ~ ~ ~ ~ ~ ~
| Modem detects change in logical
| destination metrics, and sends
|<-------Destination Update------| Destination Update signal.
-------Peer Heartbeat---------> ~ ~ ~ ~ ~ ~ ~
| Modem detects change in logical
| destination metrics, and sends
|<-------Destination Update------| Destination Update signal.
<------Destination Up ----------- Modem ~ ~ ~ ~ ~ ~ ~
| Modem detects logical destination
| is no longer reachable, and sends
|<-------Destination Down--------| Destination Down signal.
|
| Router receives Destination Down,
| updates internal state, and sends
|--------Destination Down ACK--->| Destination Down ACK signal.
------Destination Up ACK--------> Router B.2. Multicast Destination Signaling
<------Destination Update--------- Modem Router Modem Signal Description
. . . . . . . . ========================================================================
<------Destination Update--------- Modem
Modem initiates the terminate | Router detects a new multicast
| destination is in use, and sends
|--------Destination Up--------->| Destination Up signal.
|
| Modem updates internal state to
| monitor multicast destination, and
|<-------Destination Up ACK------| sends Destination Up ACK.
<------Destination Down ---------- Modem ~ ~ ~ ~ ~ ~ ~
| Modem detects change in multicast
| destination metrics, and sends
|<-------Destination Update------| Destination Update signal.
------Destination Down ACK-------> Router ~ ~ ~ ~ ~ ~ ~
| Modem detects change in multicast
| destination metrics, and sends
|<-------Destination Update------| Destination Update signal.
or ~ ~ ~ ~ ~ ~ ~
| Router detects multicast
| destination is no longer in use,
|--------Destination Down------->| and sends Destination Down signal.
|
| Modem receives Destination Down,
| updates internal state, and sends
|<-------Destination Down ACK----| Destination Down ACK signal.
Router initiates the terminate B.3. Link Characteristics Request
Router Modem Signal Description
========================================================================
------Destination Down ----------> Router Destination has already been
~ ~ ~ ~ ~ ~ ~ announced by either peer.
<------Destination Down ACK------- Modem | Router requires different
| Characteristics for the
| destination, and sends Link
|--Link Characteristics Request->| Characteristics Request signal.
|
| Modem attempts to adjust link
| status to meet the received
| request, and sends a Link
| Characteristics Request ACK
|<---Link Char. Request ACK------| signal with the new values.
Authors' Addresses Authors' Addresses
Stan Ratliff Stan Ratliff
VT iDirect VT iDirect
13861 Sunrise Valley Drive, Suite 300 13861 Sunrise Valley Drive, Suite 300
Herndon, VA 20171 Herndon, VA 20171
USA USA
Email: sratliff@idirect.net Email: sratliff@idirect.net
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