| < draft-ietf-6lo-deadline-time-00.txt | draft-ietf-6lo-deadline-time-01.txt > | |||
|---|---|---|---|---|
| 6lo Lijo Thomas | 6lo Lijo Thomas | |||
| Internet-Draft C-DAC | Internet-Draft C-DAC | |||
| Intended status: Standards Track P. Akshay | Intended status: Standards Track P. Akshay | |||
| Expires: May 17, 2018 Indian Institute of Science | Expires: September 5, 2018 Smarten Spaces | |||
| Satish Anamalamudi | Satish Anamalamudi | |||
| Huaiyin Institute of Technology | Huaiyin Institute of Technology | |||
| S.V.R.Anand | S.V.R.Anand | |||
| Malati Hegde | Malati Hegde | |||
| Indian Institute of Science | Indian Institute of Science | |||
| C. Perkins | C. Perkins | |||
| Futurewei | Futurewei | |||
| November 13, 2017 | March 4, 2018 | |||
| Packet Delivery Deadline time in 6LoWPAN Routing Header | Packet Delivery Deadline time in 6LoWPAN Routing Header | |||
| draft-ietf-6lo-deadline-time-00 | draft-ietf-6lo-deadline-time-01 | |||
| Abstract | Abstract | |||
| This document specifies a new type for the 6LoWPAN routing header | This document specifies a new type for the 6LoWPAN routing header | |||
| containing the delivery deadline time for data packets. The deadline | containing the delivery deadline time for data packets. The deadline | |||
| time enables forwarding and scheduling decisions for time critical | time enables forwarding and scheduling decisions for time critical | |||
| IoT M2M applications that need deterministic delay guarantees over | IoT M2M applications that need deterministic delay guarantees over | |||
| constrained networks and operate within time-synchronized networks. | constrained networks and operate within time-synchronized networks. | |||
| Status of This Memo | Status of This Memo | |||
| skipping to change at page 1, line 42 ¶ | skipping to change at page 1, line 42 ¶ | |||
| Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
| Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
| working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
| Drafts is at https://datatracker.ietf.org/drafts/current/. | Drafts is at https://datatracker.ietf.org/drafts/current/. | |||
| Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
| and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
| time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
| material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
| This Internet-Draft will expire on May 17, 2018. | This Internet-Draft will expire on September 5, 2018. | |||
| Copyright Notice | Copyright Notice | |||
| Copyright (c) 2017 IETF Trust and the persons identified as the | Copyright (c) 2018 IETF Trust and the persons identified as the | |||
| document authors. All rights reserved. | document authors. All rights reserved. | |||
| This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
| Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
| (https://trustee.ietf.org/license-info) in effect on the date of | (https://trustee.ietf.org/license-info) in effect on the date of | |||
| publication of this document. Please review these documents | publication of this document. Please review these documents | |||
| carefully, as they describe your rights and restrictions with respect | carefully, as they describe your rights and restrictions with respect | |||
| to this document. Code Components extracted from this document must | to this document. Code Components extracted from this document must | |||
| include Simplified BSD License text as described in Section 4.e of | include Simplified BSD License text as described in Section 4.e of | |||
| the Trust Legal Provisions and are provided without warranty as | the Trust Legal Provisions and are provided without warranty as | |||
| described in the Simplified BSD License. | described in the Simplified BSD License. | |||
| Table of Contents | Table of Contents | |||
| 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 | |||
| 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 | 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 | |||
| 3. 6LoRHE Generic Format . . . . . . . . . . . . . . . . . . . . 3 | 3. 6LoRHE Generic Format . . . . . . . . . . . . . . . . . . . . 3 | |||
| 4. Deadline-6LoRHE . . . . . . . . . . . . . . . . . . . . . . . 3 | 4. Deadline-6LoRHE . . . . . . . . . . . . . . . . . . . . . . . 4 | |||
| 5. Deadline-6LoRHE Format . . . . . . . . . . . . . . . . . . . 4 | 5. Deadline-6LoRHE Format . . . . . . . . . . . . . . . . . . . 5 | |||
| 6. Deadline-6LoRHE in Three Network Scenarios . . . . . . . . . 6 | 6. Deadline-6LoRHE in Three Network Scenarios . . . . . . . . . 6 | |||
| 6.1. Scenario 1: Endpoints in the same DODAG (N1) in non- | 6.1. Scenario 1: Endpoints in the same DODAG (N1) in non- | |||
| storing mode. . . . . . . . . . . . . . . . . . . . . . . 6 | storing mode. . . . . . . . . . . . . . . . . . . . . . . 7 | |||
| 6.2. Scenario 2: Endpoints in Networks with Dissimilar L2 | 6.2. Scenario 2: Endpoints in Networks with Dissimilar L2 | |||
| Technologies. . . . . . . . . . . . . . . . . . . . . . . 7 | Technologies. . . . . . . . . . . . . . . . . . . . . . . 8 | |||
| 6.3. Scenario 3: Packet transmission across different DODAGs | 6.3. Scenario 3: Packet transmission across different DODAGs | |||
| (N1 to N2). . . . . . . . . . . . . . . . . . . . . . . . 8 | (N1 to N2). . . . . . . . . . . . . . . . . . . . . . . . 9 | |||
| 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 | 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 | |||
| 8. Security Considerations . . . . . . . . . . . . . . . . . . . 10 | 8. Security Considerations . . . . . . . . . . . . . . . . . . . 10 | |||
| 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10 | 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10 | |||
| 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 | 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 | |||
| 10.1. Normative References . . . . . . . . . . . . . . . . . . 10 | 10.1. Normative References . . . . . . . . . . . . . . . . . . 10 | |||
| 10.2. Informative References . . . . . . . . . . . . . . . . . 11 | 10.2. Informative References . . . . . . . . . . . . . . . . . 11 | |||
| Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 | Appendix A. Changes Since draft-ietf-6lo-deadline-time-00 . . . 12 | |||
| Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 | ||||
| 1. Introduction | 1. Introduction | |||
| Low Power and Lossy Networks (LLNs) are likely to be deployed for | Low Power and Lossy Networks (LLNs) are likely to be deployed for | |||
| real time industrial applications requiring end-to-end delay | real time industrial applications requiring end-to-end delay | |||
| guarantees [I-D.grossman-detnet-use-cases]. A Deterministic Network | guarantees [I-D.ietf-detnet-use-cases]. A Deterministic Network | |||
| ("detnet") typically requires some data packets to reach their | ("detnet") typically requires some data packets to reach their | |||
| receivers within strict time bounds. Intermediate nodes use the | receivers within strict time bounds. Intermediate nodes use the | |||
| deadline information to make appropriate packet forwarding and | deadline information to make appropriate packet forwarding and | |||
| scheduling decisions to meet the time bounds. | scheduling decisions to meet the time bounds. | |||
| The draft [I-D.ietf-roll-routing-dispatch] specifies the 6LoWPAN | The draft [I-D.ietf-roll-routing-dispatch] specifies the 6LoWPAN | |||
| Routing Header (6LoRH), compression schemes for RPL routing (source | Routing Header (6LoRH), compression schemes for RPL routing (source | |||
| routing) operation [RFC6554], header compression of RPL Packet | routing) operation [RFC6554], header compression of RPL Packet | |||
| Information [RFC6553], and IP-in-IP encapsulation. This document | Information [RFC6553], and IP-in-IP encapsulation. This document | |||
| specifies a new Deadline-6LoRHE type for the 6LoWPAN Dispatch Page 1, | specifies a new Deadline-6LoRHE type for the 6LoWPAN Dispatch Page 1, | |||
| so that the deadline time of data packets can be included within the | so that the deadline time of data packets can be included within the | |||
| 6LoWPAN routing header. This document also specifies handling of the | 6LoWPAN routing header. This document also specifies handling of the | |||
| deadline time when packets traverse through time-synchronized | deadline time when packets traverse through time-synchronized | |||
| networks operating in different timezones or distinct reference | networks operating in different timezones or distinct reference | |||
| clocks. | clocks. Time synchronization techniques need not be mandated by this | |||
| specificiation. There are a number of standards available for this | ||||
| purpose, including IEEE 1588 [ieee-1588], IEEE 802.1AS [dot1AS-2011], | ||||
| IEEE 802.15.4-2015 TSCH [dot15-tsch], and more. | ||||
| 2. Terminology | 2. Terminology | |||
| The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | |||
| "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and | "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and | |||
| "OPTIONAL" in this document are to be interpreted as described in | "OPTIONAL" in this document are to be interpreted as described in | |||
| [RFC2119]. | [RFC2119]. | |||
| This document uses terminology consistent with the terminology used | This document uses terminology consistent with the terminology used | |||
| in [RFC6550] and [I-D.ietf-6tisch-terminology]. Also, in this | in [RFC6550] and [I-D.ietf-6tisch-terminology]. Also, in this | |||
| skipping to change at page 4, line 37 ¶ | skipping to change at page 4, line 44 ¶ | |||
| Time as expressed using the reference clock of the outgoing interface | Time as expressed using the reference clock of the outgoing interface | |||
| into the new network. This is the same as the current time when the | into the new network. This is the same as the current time when the | |||
| packet is transmitted into the new network, minus the delay already | packet is transmitted into the new network, minus the delay already | |||
| experienced by the packet, say 't'. In effect, to the newly entered | experienced by the packet, say 't'. In effect, to the newly entered | |||
| network, the packet will appear to have originated 't' time units | network, the packet will appear to have originated 't' time units | |||
| earlier with respect to the reference clock of the new network. | earlier with respect to the reference clock of the new network. | |||
| Origination Time in new network = current_time_in_new_network - | Origination Time in new network = current_time_in_new_network - | |||
| delay_already_experienced_in_previous_network(s) | delay_already_experienced_in_previous_network(s) | |||
| There are multiple ways that a packet can be delayed, including | ||||
| propagation delay and queuing delays. Sometimes there are processing | ||||
| delays as well. For the purpose of determining whether or not the | ||||
| deadline has already passed, these various delays are not | ||||
| distinguished. | ||||
| 5. Deadline-6LoRHE Format | 5. Deadline-6LoRHE Format | |||
| 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 | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| |1|0|1| Length | 6LoRH Type |O|D| DTL | OTL | TU| EXP | Rsv | | |1|0|1| Length | 6LoRH Type |O|D| DTL | OTL | TU| EXP | Rsv | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | DT (variable length) | OT(variable length)(optional) | | | DT (variable length) | OT(variable length)(optional) | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| skipping to change at page 5, line 12 ¶ | skipping to change at page 5, line 27 ¶ | |||
| Length (5 bits): Length represents the total length of the Deadline- | Length (5 bits): Length represents the total length of the Deadline- | |||
| 6LoRHE type measured in octets. | 6LoRHE type measured in octets. | |||
| 6LoRH Type: TBD | 6LoRH Type: TBD | |||
| O flag (1bit): Indicates the presence of Origination Time field. '1' | O flag (1bit): Indicates the presence of Origination Time field. '1' | |||
| means the OT field is present, and '0' means it is absent. | means the OT field is present, and '0' means it is absent. | |||
| D flag (1 bit): The 'D' flag, set by the Sender, indicates the action | D flag (1 bit): The 'D' flag, set by the Sender, indicates the action | |||
| to be taken when a 6LR detects that the deadline time has elapsed. | to be taken when a 6LR detects that the deadline time has elapsed. | |||
| If 'D' bit is 1, then the 6LR SHOULD drop the packet if the deadline | If 'D' bit is 1, then the 6LR MUST drop the packet if the deadline | |||
| time is elapsed. If 'D' bit is 0, then the 6LR MAY ignore the | time is elapsed. If 'D' bit is 0, then the 6LR MAY ignore the | |||
| deadline time and forward the packet. | deadline time and forward the packet. | |||
| DTL (3 bits): Length of DT field. | DTL (3 bits): Length of DT field. | |||
| OTL (3 bits) : Length of OT field. | OTL (3 bits) : Length of OT field. | |||
| For example, DTL = 000 means the deadline time in the 6LoRHE is 1 | For example, DTL = 000 means the deadline time in the 6LoRHE is 1 | |||
| octet (8 bits) long. Similarly, OTL = 111 means the origination | octet (8 bits) long. Similarly, OTL = 111 means the origination | |||
| time is 8 octets (64 bits) long. | time is 8 octets (64 bits) long. | |||
| skipping to change at page 7, line 33 ¶ | skipping to change at page 8, line 18 ¶ | |||
| 6.2. Scenario 2: Endpoints in Networks with Dissimilar L2 Technologies. | 6.2. Scenario 2: Endpoints in Networks with Dissimilar L2 Technologies. | |||
| In scenario 2, shown in Figure 5, the Sender 'S' (belonging to DODAG | In scenario 2, shown in Figure 5, the Sender 'S' (belonging to DODAG | |||
| 1) has IP datagram to be routed to a Receiver 'R' over a time- | 1) has IP datagram to be routed to a Receiver 'R' over a time- | |||
| synchronized IPv6 network. For the route segment from 'S' to 6LBR, | synchronized IPv6 network. For the route segment from 'S' to 6LBR, | |||
| 'S' includes a Deadline-6LoRHE. Subsequently, 6LR will perform hop- | 'S' includes a Deadline-6LoRHE. Subsequently, 6LR will perform hop- | |||
| by-hop operation to forward the packet towards the 6LBR. Once the IP | by-hop operation to forward the packet towards the 6LBR. Once the IP | |||
| datagram reaches 6LBR of DODAG1, it encodes the deadline time (and, | datagram reaches 6LBR of DODAG1, it encodes the deadline time (and, | |||
| if available, the origination time) into the In-band OAM header | if available, the origination time) into the In-band OAM header | |||
| extension, [I-D.brockners-inband-oam-data] and passes the datagram to | extension, [I-D.ietf-ippm-ioam-data] and passes the datagram to the | |||
| the IPv6 layer for further routing. | IPv6 layer for further routing. | |||
| +----------------+ | +----------------+ | |||
| | Time | | | Time | | |||
| | synchronized |------R | | synchronized |------R | |||
| | Network | | | Network | | |||
| +----------------+ | +----------------+ | |||
| | | | | |||
| | | | | |||
| ----------+----------- | ----------+----------- | |||
| ^ | | ^ | | |||
| skipping to change at page 10, line 26 ¶ | skipping to change at page 10, line 40 ¶ | |||
| format is logically equivalent and does not create an opening for a | format is logically equivalent and does not create an opening for a | |||
| new threat when compared to [RFC6550], [RFC6553] and [RFC6554]. | new threat when compared to [RFC6550], [RFC6553] and [RFC6554]. | |||
| 9. Acknowledgements | 9. Acknowledgements | |||
| The authors thank Pascal Thubert for suggesting the idea and | The authors thank Pascal Thubert for suggesting the idea and | |||
| encouraging the work. Thanks to Shwetha Bhandari's suggestions which | encouraging the work. Thanks to Shwetha Bhandari's suggestions which | |||
| were instrumental in extending the timing information to | were instrumental in extending the timing information to | |||
| heterogeneous networks. The authors acknowledge the 6TiSCH WG | heterogeneous networks. The authors acknowledge the 6TiSCH WG | |||
| members for their inputs on the mailing list. Special thanks to | members for their inputs on the mailing list. Special thanks to | |||
| Jerry Daniel,Shalu Rajendran, Seema Kumar, Avinash Mohan and Anita | Jerry Daniel, Seema Kumar, Avinash Mohan, Shalu Rajendran and Anita | |||
| Varghese for their support and valuable feedback. | Varghese for their support and valuable feedback. | |||
| 10. References | 10. References | |||
| 10.1. Normative References | 10.1. Normative References | |||
| [I-D.ietf-6tisch-terminology] | [I-D.ietf-6tisch-terminology] | |||
| Palattella, M., Thubert, P., Watteyne, T., and Q. Wang, | Palattella, M., Thubert, P., Watteyne, T., and Q. Wang, | |||
| "Terminology in IPv6 over the TSCH mode of IEEE | "Terms Used in IPv6 over the TSCH mode of IEEE 802.15.4e", | |||
| 802.15.4e", draft-ietf-6tisch-terminology-09 (work in | draft-ietf-6tisch-terminology-10 (work in progress), March | |||
| progress), June 2017. | 2018. | |||
| [I-D.ietf-roll-routing-dispatch] | [I-D.ietf-roll-routing-dispatch] | |||
| Thubert, P., Bormann, C., Toutain, L., and R. Cragie, | Thubert, P., Bormann, C., Toutain, L., and R. Cragie, | |||
| "6LoWPAN Routing Header", draft-ietf-roll-routing- | "6LoWPAN Routing Header", draft-ietf-roll-routing- | |||
| dispatch-05 (work in progress), October 2016. | dispatch-05 (work in progress), October 2016. | |||
| [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, | Requirement Levels", BCP 14, RFC 2119, | |||
| DOI 10.17487/RFC2119, March 1997, | DOI 10.17487/RFC2119, March 1997, | |||
| <https://www.rfc-editor.org/info/rfc2119>. | <https://www.rfc-editor.org/info/rfc2119>. | |||
| skipping to change at page 11, line 31 ¶ | skipping to change at page 11, line 46 ¶ | |||
| <https://www.rfc-editor.org/info/rfc6553>. | <https://www.rfc-editor.org/info/rfc6553>. | |||
| [RFC6554] Hui, J., Vasseur, JP., Culler, D., and V. Manral, "An IPv6 | [RFC6554] Hui, J., Vasseur, JP., Culler, D., and V. Manral, "An IPv6 | |||
| Routing Header for Source Routes with the Routing Protocol | Routing Header for Source Routes with the Routing Protocol | |||
| for Low-Power and Lossy Networks (RPL)", RFC 6554, | for Low-Power and Lossy Networks (RPL)", RFC 6554, | |||
| DOI 10.17487/RFC6554, March 2012, | DOI 10.17487/RFC6554, March 2012, | |||
| <https://www.rfc-editor.org/info/rfc6554>. | <https://www.rfc-editor.org/info/rfc6554>. | |||
| 10.2. Informative References | 10.2. Informative References | |||
| [I-D.brockners-inband-oam-data] | [dot15-tsch] | |||
| Brockners, F., Bhandari, S., Pignataro, C., Gredler, H., | P802.11, "IEEE Standard for Low-Rate Wireless Networks, | |||
| Leddy, J., Youell, S., Mizrahi, T., Mozes, D., Lapukhov, | Part 15.4, IEEE Std 802.15.4-2015", April 2016. | |||
| P., Chang, R., and d. daniel.bernier@bell.ca, "Data Fields | ||||
| for In-situ OAM", draft-brockners-inband-oam-data-07 (work | ||||
| in progress), July 2017. | ||||
| [I-D.grossman-detnet-use-cases] | [dot1AS-2011] | |||
| Grossman, E., Gunther, C., Thubert, P., Wetterwald, P., | IEEE 802.1AS Working Group, "IEEE Standard for Local and | |||
| Raymond, J., Korhonen, J., Kaneko, Y., Das, S., and Y. | Metropolitan Area Networks - Timing and Synchronization | |||
| Zha, "Deterministic Networking Use Cases", draft-grossman- | for Time-Sensitive Applications in Bridged Local Area | |||
| detnet-use-cases-01 (work in progress), November 2015. | Networks", March 2011. | |||
| [I-D.ietf-6lo-backbone-router] | [I-D.ietf-6lo-backbone-router] | |||
| Thubert, P., "IPv6 Backbone Router", draft-ietf-6lo- | Thubert, P., "IPv6 Backbone Router", draft-ietf-6lo- | |||
| backbone-router-04 (work in progress), July 2017. | backbone-router-06 (work in progress), February 2018. | |||
| [I-D.ietf-detnet-use-cases] | ||||
| Grossman, E., "Deterministic Networking Use Cases", draft- | ||||
| ietf-detnet-use-cases-14 (work in progress), February | ||||
| 2018. | ||||
| [I-D.ietf-ippm-ioam-data] | ||||
| Brockners, F., Bhandari, S., Pignataro, C., Gredler, H., | ||||
| Leddy, J., Youell, S., Mizrahi, T., Mozes, D., Lapukhov, | ||||
| P., Chang, R., and d. daniel.bernier@bell.ca, "Data Fields | ||||
| for In-situ OAM", draft-ietf-ippm-ioam-data-01 (work in | ||||
| progress), October 2017. | ||||
| [I-D.ietf-roll-useofrplinfo] | [I-D.ietf-roll-useofrplinfo] | |||
| Robles, I., Richardson, M., and P. Thubert, "When to use | Robles, I., Richardson, M., and P. Thubert, "When to use | |||
| RFC 6553, 6554 and IPv6-in-IPv6", draft-ietf-roll- | RFC 6553, 6554 and IPv6-in-IPv6", draft-ietf-roll- | |||
| useofrplinfo-19 (work in progress), October 2017. | useofrplinfo-22 (work in progress), March 2018. | |||
| [I-D.vilajosana-6tisch-minimal] | [ieee-1588] | |||
| Vilajosana, X. and K. Pister, "Minimal 6TiSCH | Precise Time and Time Interval Working Group, "IEEE Std | |||
| Configuration", draft-vilajosana-6tisch-minimal-00 (work | 1588-2008 Standard for a Precision Clock Synchronization | |||
| in progress), October 2013. | Protocol for Networked Measurement and Control Systems", | |||
| July 2008. | ||||
| Appendix A. Changes Since draft-ietf-6lo-deadline-time-00 | ||||
| This section lists the changes between draft-ietf-6lo-deadline-time | ||||
| revisions ...-00.txt and ...-01.txt. | ||||
| o Changed "SHOULD drop" to "MUST drop" a packet if the deadline is | ||||
| passed (see Section 5). | ||||
| o Added explanatory text about how packet delays might arise. (see | ||||
| Section 4). | ||||
| o Mentioned availability of time-synchronization protocols (see | ||||
| Section 1). . | ||||
| o Updated bibliographic citations. | ||||
| o Alphabetized contributor names. | ||||
| o Added this section. | ||||
| Authors' Addresses | Authors' Addresses | |||
| Lijo Thomas | Lijo Thomas | |||
| C-DAC | C-DAC | |||
| Trivandrum 695033 | Trivandrum 695033 | |||
| India | India | |||
| Email: lijo@cdac.in | Email: lijo@cdac.in | |||
| P.M. Akshay | P.M. Akshay | |||
| Indian Institute of Science | Smarten Spaces | |||
| Bangalore 560012 | Bangalore 560103 | |||
| India | India | |||
| Email: akshaypm@ece.iisc.ernet.in | Email: akshay.pm@smartenspaces.com | |||
| Satish Anamalamudi | Satish Anamalamudi | |||
| Huaiyin Institute of Technology | Huaiyin Institute of Technology | |||
| No.89 North Beijing Road, Qinghe District | No.89 North Beijing Road, Qinghe District | |||
| Huaian | Huaian | |||
| China | China | |||
| Email: satishnaidu80@gmail.com | Email: satishnaidu80@gmail.com | |||
| S.V.R Anand | S.V.R Anand | |||
| End of changes. 24 change blocks. | ||||
| 41 lines changed or deleted | 81 lines changed or added | |||
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