< draft-ietf-pce-binding-label-sid-10.txt   draft-ietf-pce-binding-label-sid-11.txt >
PCE Working Group S. Sivabalan PCE Working Group S. Sivabalan
Internet-Draft Ciena Corporation Internet-Draft Ciena Corporation
Intended status: Standards Track C. Filsfils Intended status: Standards Track C. Filsfils
Expires: January 9, 2022 Cisco Systems, Inc. Expires: April 18, 2022 Cisco Systems, Inc.
J. Tantsura J. Tantsura
Microsoft Corporation Microsoft Corporation
S. Previdi S. Previdi
C. Li, Ed. C. Li, Ed.
Huawei Technologies Huawei Technologies
July 8, 2021 October 15, 2021
Carrying Binding Label/Segment Identifier in PCE-based Networks. Carrying Binding Label/Segment Identifier in PCE-based Networks.
draft-ietf-pce-binding-label-sid-10 draft-ietf-pce-binding-label-sid-11
Abstract Abstract
In order to provide greater scalability, network confidentiality, and In order to provide greater scalability, network confidentiality, and
service independence, Segment Routing (SR) utilizes a Binding Segment service independence, Segment Routing (SR) utilizes a Binding Segment
Identifier (BSID). It is possible to associate a BSID to an RSVP-TE- Identifier (BSID). It is possible to associate a BSID to an RSVP-TE-
signaled Traffic Engineering Label Switched Path or an SR Traffic signaled Traffic Engineering Label Switched Path or an SR Traffic
Engineering path. The BSID can be used by an upstream node for Engineering path. The BSID can be used by an upstream node for
steering traffic into the appropriate TE path to enforce SR policies. steering traffic into the appropriate TE path to enforce SR policies.
This document specifies the binding value as an MPLS label or Segment This document specifies the binding value as an MPLS label or Segment
Identifier. It further specifies an approach for reporting binding Identifier. It further specifies an approach for reporting binding
label/SID by a Path Computation Client (PCC) to the Path Computation label/Segment Identifier (SID) by a Path Computation Client (PCC) to
Element (PCE) to support PCE-based Traffic Engineering policies. the Path Computation Element (PCE) to support PCE-based Traffic
Engineering policies.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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 January 9, 2022. This Internet-Draft will expire on April 18, 2022.
Copyright Notice Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the Copyright (c) 2021 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
skipping to change at page 2, line 31 skipping to change at page 2, line 31
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 5 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 5
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Path Binding TLV . . . . . . . . . . . . . . . . . . . . . . 5 4. Path Binding TLV . . . . . . . . . . . . . . . . . . . . . . 5
4.1. SRv6 Endpoint Behavior and SID Structure . . . . . . . . 7 4.1. SRv6 Endpoint Behavior and SID Structure . . . . . . . . 7
5. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Binding SID in SR-ERO . . . . . . . . . . . . . . . . . . . . 10 6. Binding SID in SR-ERO . . . . . . . . . . . . . . . . . . . . 10
7. Binding SID in SRv6-ERO . . . . . . . . . . . . . . . . . . . 11 7. Binding SID in SRv6-ERO . . . . . . . . . . . . . . . . . . . 11
8. PCE Allocation of Binding label/SID . . . . . . . . . . . . . 11 8. PCE Allocation of Binding label/SID . . . . . . . . . . . . . 11
9. Implementation Status . . . . . . . . . . . . . . . . . . . . 13 9. Implementation Status . . . . . . . . . . . . . . . . . . . . 12
9.1. Huawei . . . . . . . . . . . . . . . . . . . . . . . . . 13 9.1. Huawei . . . . . . . . . . . . . . . . . . . . . . . . . 13
9.2. Cisco . . . . . . . . . . . . . . . . . . . . . . . . . . 13 9.2. Cisco . . . . . . . . . . . . . . . . . . . . . . . . . . 13
10. Security Considerations . . . . . . . . . . . . . . . . . . . 14 10. Security Considerations . . . . . . . . . . . . . . . . . . . 14
11. Manageability Considerations . . . . . . . . . . . . . . . . 14 11. Manageability Considerations . . . . . . . . . . . . . . . . 14
11.1. Control of Function and Policy . . . . . . . . . . . . . 14 11.1. Control of Function and Policy . . . . . . . . . . . . . 14
11.2. Information and Data Models . . . . . . . . . . . . . . 14 11.2. Information and Data Models . . . . . . . . . . . . . . 14
11.3. Liveness Detection and Monitoring . . . . . . . . . . . 15 11.3. Liveness Detection and Monitoring . . . . . . . . . . . 15
11.4. Verify Correct Operations . . . . . . . . . . . . . . . 15 11.4. Verify Correct Operations . . . . . . . . . . . . . . . 15
11.5. Requirements On Other Protocols . . . . . . . . . . . . 15 11.5. Requirements On Other Protocols . . . . . . . . . . . . 15
11.6. Impact On Network Operations . . . . . . . . . . . . . . 15 11.6. Impact On Network Operations . . . . . . . . . . . . . . 15
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
12.1. PCEP TLV Type Indicators . . . . . . . . . . . . . . . . 15 12.1. PCEP TLV Type Indicators . . . . . . . . . . . . . . . . 15
12.1.1. TE-PATH-BINDING TLV . . . . . . . . . . . . . . . . 15 12.1.1. TE-PATH-BINDING TLV . . . . . . . . . . . . . . . . 15
12.2. LSP Object . . . . . . . . . . . . . . . . . . . . . . . 16 12.2. LSP Object . . . . . . . . . . . . . . . . . . . . . . . 16
12.3. PCEP Error Type and Value . . . . . . . . . . . . . . . 16 12.3. PCEP Error Type and Value . . . . . . . . . . . . . . . 16
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 17 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
14.1. Normative References . . . . . . . . . . . . . . . . . . 17 14.1. Normative References . . . . . . . . . . . . . . . . . . 17
14.2. Informative References . . . . . . . . . . . . . . . . . 19 14.2. Informative References . . . . . . . . . . . . . . . . . 19
Appendix A. Contributor Addresses . . . . . . . . . . . . . . . 20 Appendix A. Contributor Addresses . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction 1. Introduction
A Path Computation Element (PCE) can compute Traffic Engineering A Path Computation Element (PCE) can compute Traffic Engineering
paths (TE paths) through a network where those paths are subject to paths (TE paths) through a network where those paths are subject to
various constraints. Currently, TE paths are set up using either the various constraints. Currently, TE paths are set up using either the
RSVP-TE signaling protocol or Segment Routing (SR). We refer to such RSVP-TE signaling protocol or Segment Routing (SR). We refer to such
paths as RSVP-TE paths and SR-TE paths respectively in this document. paths as RSVP-TE paths and SR-TE paths respectively in this document.
As per [RFC8402] SR allows a head-end node to steer a packet flow As per [RFC8402] SR allows a head-end node to steer a packet flow
along any path. The head-end node is said to steer a flow into a along any path. The head-end node is said to steer a flow into a
Segment Routing Policy (SR Policy). Further, as per Segment Routing Policy (SR Policy). Further, as per
[I-D.ietf-spring-segment-routing-policy], an SR Policy is a framework [I-D.ietf-spring-segment-routing-policy], an SR Policy is a framework
that enables the instantiation of an ordered list of segments on a that enables the instantiation of an ordered list of segments on a
node for implementing a source routing policy with a specific intent node for implementing a source routing policy with a specific intent
for traffic steering from that node. for traffic steering from that node.
As described in [RFC8402], a Binding Segment Identifier (BSID) is As described in [RFC8402], a Binding Segment Identifier (BSID) is
bound to a Segment Routing (SR) Policy, instantiation of which may bound to a Segment Routing (SR) Policy, instantiation of which may
involve a list of SIDs. Any packets received with an active segment involve a list of Segment Identifiers (SIDs). Any packets received
equal to a BSID are steered onto the bound SR Policy. A BSID may be with an active segment equal to a BSID are steered onto the bound SR
either a local (SR Local Block (SRLB)) or a global (SR Global Block Policy. A BSID may be either a local (SR Local Block (SRLB)) or a
(SRGB)) SID. As per Section 6.4 of global (SR Global Block (SRGB)) SID. As per Section 6.4 of
[I-D.ietf-spring-segment-routing-policy] a BSID can also be [I-D.ietf-spring-segment-routing-policy] a BSID can also be
associated with any type of interface or tunnel to enable the use of associated with any type of interface or tunnel to enable the use of
a non-SR interface or tunnel as a segment in a SID list. In this a non-SR interface or tunnel as a segment in a SID list. In this
document, binding label/SID is used to generalize the allocation of document, binding label/SID is used to generalize the allocation of
binding value for both SR and non-SR paths. binding value for both SR and non-SR paths.
[RFC5440] describes the PCE communication Protocol(PCEP) for [RFC5440] describes the PCE communication Protocol(PCEP) for
communication between a Path Computation Client (PCC) and a PCE or communication between a Path Computation Client (PCC) and a PCE or
between a pair of PCEs as per [RFC4655]. [RFC8231] specifies between a pair of PCEs as per [RFC4655]. [RFC8231] specifies
extensions to PCEP that allow a PCC to delegate its Label Switched extensions to PCEP that allow a PCC to delegate its Label Switched
skipping to change at page 3, line 50 skipping to change at page 3, line 50
the path and characteristics. the path and characteristics.
[RFC8664] provides a mechanism for a PCE (acting as a network [RFC8664] provides a mechanism for a PCE (acting as a network
controller) to instantiate SR-TE paths (candidate paths) for an SR controller) to instantiate SR-TE paths (candidate paths) for an SR
Policy onto a head-end node (acting as a PCC) using PCEP. For more Policy onto a head-end node (acting as a PCC) using PCEP. For more
information on the SR Policy Architecture, see information on the SR Policy Architecture, see
[I-D.ietf-spring-segment-routing-policy]. [I-D.ietf-spring-segment-routing-policy].
A binding label/SID has local significance to the ingress node of the A binding label/SID has local significance to the ingress node of the
corresponding TE path. When a stateful PCE is deployed for setting corresponding TE path. When a stateful PCE is deployed for setting
up TE paths, it may be desirable for PCC to report the binding label/ up TE paths, it may be desirable for a PCC to report the binding
SID to the stateful PCE for the purpose of enforcing end-to-end TE/SR label/SID to the stateful PCE for the purpose of enforcing end-to-end
policy. A sample Data Center (DC) use-case is illustrated in the TE/SR policy. A sample Data Center (DC) use-case is illustrated in
Figure 1. In the MPLS DC network, an SR LSP (without traffic Figure 1. In the MPLS DC network, an SR LSP (without traffic
engineering) is established using a prefix SID advertised by BGP (see engineering) is established using a prefix SID advertised by BGP (see
[RFC8669]). In the IP/MPLS WAN, an SR-TE LSP is set up using the [RFC8669]). In the IP/MPLS WAN, an SR-TE LSP is set up using the
PCE. The list of SIDs of the SR-TE LSP is {A, B, C, D}. The gateway PCE. The list of SIDs of the SR-TE LSP is {A, B, C, D}. The gateway
node 1 (which is the PCC) allocates a binding SID X and reports it to node 1 (which is the PCC) allocates a binding SID X and reports it to
the PCE. In order for the access node to steer the traffic over the the PCE. In order for the access node to steer the traffic over the
SR-TE LSP, the PCE passes the SID stack {Y, X} where Y is the prefix SR-TE LSP, the PCE passes the SID stack {Y, X} where Y is the prefix
SID of the gateway node-1 to the access node. In the absence of the SID of the gateway node-1 to the access node. In the absence of the
binding SID X, the PCE should pass the SID stack {Y, A, B, C, D} to binding SID X, the PCE would pass the SID stack {Y, A, B, C, D} to
the access node. This example also illustrates the additional the access node. This example also illustrates the additional
benefit of using the binding SID to reduce the number of SIDs imposed benefit of using the binding label/SID to reduce the number of SIDs
on the access nodes with a limited forwarding capacity. imposed by the access nodes with a limited forwarding capacity.
SID stack SID stack
{Y, X} +-----+ {Y, X} +-----+
_ _ _ _ _ _ _ _ _ _ _ _ _ _| PCE | _ _ _ _ _ _ _ _ _ _ _ _ _ _| PCE |
| +-----+ | +-----+
| ^ | ^
| | Binding | | Binding
| .-----. | SID (X) .-----. | .-----. | SID (X) .-----.
| ( ) | ( ) | ( ) | ( )
V .--( )--. | .--( )--. V .--( )--. | .--( )--.
+------+ ( ) +-------+ ( ) +-------+ +------+ ( ) +-------+ ( ) +-------+
|Access|_( MPLS DC Network )_|Gateway|_( IP/MPLS WAN )_|Gateway| |Access|_( MPLS DC Network )_|Gateway|_( IP/MPLS WAN )_|Gateway|
| Node | ( ==============> ) |Node-1 | ( ================> ) |Node-2 | | Node | ( ==============> ) |Node-1 | ( ================> ) |Node-2 |
+------+ ( SR path ) +-------+ ( SR-TE path ) +-------+ +------+ ( SR path ) +-------+ ( SR-TE path ) +-------+
'--( )--' Prefix '--( )--' '--( )--' Prefix '--( )--'
( ) SID of ( ) ( ) SID of ( )
'-----' Node-1 '-----' '-----' Node-1 '-----'
is Y SIDs for SR-TE LSP: is Y SIDs for SR-TE LSP:
{A, B, C, D} {A, B, C, D}
Figure 1: A sample Use-case of Binding SID Figure 1: A Sample Use-case of Binding SID
A PCC could report to the stateful PCE the binding label/SID it A PCC could report to the stateful PCE the binding label/SID it
allocated via a Path Computation LSP State Report (PCRpt) message. allocated via a Path Computation LSP State Report (PCRpt) message.
It is also possible for a stateful PCE to request a PCC to allocate a It is also possible for a stateful PCE to request a PCC to allocate a
specific binding label/SID by sending a Path Computation LSP Update specific binding label/SID by sending a Path Computation LSP Update
Request (PCUpd) message. If the PCC can successfully allocate the Request (PCUpd) message. If the PCC can successfully allocate the
specified binding value, it reports the binding value to the PCE. specified binding value, it reports the binding value to the PCE.
Otherwise, the PCC sends an error message to the PCE indicating the Otherwise, the PCC sends an error message to the PCE indicating the
cause of the failure. A local policy or configuration at the PCC cause of the failure. A local policy or configuration at the PCC
SHOULD dictate if the binding label/SID needs to be assigned. SHOULD dictate if the binding label/SID needs to be assigned.
skipping to change at page 5, line 50 skipping to change at page 5, line 50
RSVP-TE: Resource ReserVation Protocol-Traffic Engineering. RSVP-TE: Resource ReserVation Protocol-Traffic Engineering.
SID: Segment Identifier. SID: Segment Identifier.
SR: Segment Routing. SR: Segment Routing.
4. Path Binding TLV 4. Path Binding TLV
The new optional TLV called "TE-PATH-BINDING TLV" (whose format is The new optional TLV called "TE-PATH-BINDING TLV" (whose format is
shown in the Figure 2) is defined to carry the binding label/SID for shown in Figure 2) is defined to carry the binding label/SID for a TE
a TE path. This TLV is associated with the LSP object specified in path. This TLV is associated with the LSP object specified in
[RFC8231]. This TLV can also be carried in the PCEP-ERROR object [RFC8231]. This TLV can also be carried in the PCEP-ERROR object
[RFC5440] in case of error. Multiple instance of TE-PATH-BINDING [RFC5440] in case of error. Multiple instances of TE-PATH-BINDING
TLVs MAY be present in the LSP and PCEP-ERROR object. The type of TLVs MAY be present in the LSP and PCEP-ERROR object. The type of
this TLV is 55 (early allocated by IANA). The length is variable. this TLV is 55 (early allocated by IANA). The length is variable.
[Note to RFC Editor: Please remove "(early allocated by IANA)" before
publication]
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 55 | Length | | Type = 55 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BT | Flags | Reserved | | BT | Flags | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Binding Value (variable length) ~ ~ Binding Value (variable length) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: TE-PATH-BINDING TLV Figure 2: TE-PATH-BINDING TLV
TE-PATH-BINDING TLV is a generic TLV such that it is able to carry TE-PATH-BINDING TLV is a generic TLV such that it is able to carry
binding label/SID (i.e. MPLS label or SRv6 SID). It is formatted binding label/SID (i.e. MPLS label or SRv6 SID). It is formatted
according to the rules specified in [RFC5440]. The value portion of according to the rules specified in [RFC5440]. The value portion of
the TLV comprises: the TLV comprises:
Binding Type (BT): A one-octet field identifies the type of binding Binding Type (BT): A one-octet field that identifies the type of
included in the TLV. This document specifies the following BT binding included in the TLV. This document specifies the following
values: BT values:
o BT = 0: The binding value is a 20-bit MPLS label value. The TLV o BT = 0: The binding value is a 20-bit MPLS label value. The TLV
is padded to 4-bytes alignment. The Length MUST be set to 7 and is padded to 4-bytes alignment. The Length MUST be set to 7 (the
the first 20 bits are used to encode the MPLS label value. padding is not included in the length, as per [RFC5440]
Section 7.1) and the first 20 bits are used to encode the MPLS
label value.
o BT = 1: The binding value is a 32-bit MPLS label stack entry as o BT = 1: The binding value is a 32-bit MPLS label stack entry as
per [RFC3032] with Label, TC [RFC5462], S, and TTL values encoded. per [RFC3032] with Label, TC [RFC5462], S, and TTL values encoded.
Note that the receiver MAY choose to override TC, S, and TTL Note that the receiver MAY choose to override TC, S, and TTL
values according to its local policy. The Length MUST be set to values according to its local policy. The Length MUST be set to
8. 8.
o BT = 2: The binding value is an SRv6 SID with a format of a o BT = 2: The binding value is an SRv6 SID with the format of a
16-octet IPv6 address, representing the binding SID for SRv6. The 16-octet IPv6 address, representing the binding SID for SRv6. The
Length MUST be set to 20. Length MUST be set to 20.
o BT = 3: The binding value is a 24 octet field, defined in o BT = 3: The binding value is a 24 octet field, defined in
Section 4.1, that contains the SRv6 SID as well as its Behavior Section 4.1, that contains the SRv6 SID as well as its Behavior
and Structure. The Length MUST be set to 28. and Structure. The Length MUST be set to 28.
Section 12.1.1 defines the IANA registry used to maintain all these Section 12.1.1 defines the IANA registry used to maintain all these
binding types as well as any future ones. Note that multiple TE- binding types as well as any future ones. Note that multiple TE-
PATH-BINDING TLVs with different Binding Types MAY be present for the PATH-BINDING TLVs with different Binding Types MAY be present for the
skipping to change at page 7, line 40 skipping to change at page 7, line 45
a 4-octet boundary. When the BT is 0, the 20 bits represent the MPLS a 4-octet boundary. When the BT is 0, the 20 bits represent the MPLS
label. When the BT is 1, the 32 bits represent the MPLS label stack label. When the BT is 1, the 32 bits represent the MPLS label stack
entry as per [RFC3032]. When the BT is 2, the 128 bits represent the entry as per [RFC3032]. When the BT is 2, the 128 bits represent the
SRv6 SID. When the BT is 3, the Binding Value also contains the SRv6 SRv6 SID. When the BT is 3, the Binding Value also contains the SRv6
Endpoint Behavior and SID Structure, defined in Section 4.1. Endpoint Behavior and SID Structure, defined in Section 4.1.
4.1. SRv6 Endpoint Behavior and SID Structure 4.1. SRv6 Endpoint Behavior and SID Structure
This section specifies the format of the Binding Value in the TE- This section specifies the format of the Binding Value in the TE-
PATH-BINDING TLV when the BT is set to 3 for the SRv6 Binding SIDs PATH-BINDING TLV when the BT is set to 3 for the SRv6 Binding SIDs
[RFC8986], as shown in Figure 4. [RFC8986]. The format is shown in Figure 4.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SRv6 Binding SID (16 octets) | | SRv6 Binding SID (16 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Endpoint Behavior | | Reserved | Endpoint Behavior |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LB Length | LN Length | Fun. Length | Arg. Length | | LB Length | LN Length | Fun. Length | Arg. Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 10, line 5 skipping to change at page 10, line 5
PCEP-ERROR object. PCEP-ERROR object.
If a PCE wishes to request the withdrawal of a previously reported If a PCE wishes to request the withdrawal of a previously reported
binding value, it MUST send a PCUpd message with the specific TE- binding value, it MUST send a PCUpd message with the specific TE-
PATH-BINDING TLV with R flag set to 1. If a PCE wishes to modify a PATH-BINDING TLV with R flag set to 1. If a PCE wishes to modify a
previously requested binding value, it MUST request the withdrawal of previously requested binding value, it MUST request the withdrawal of
the former binding value (with R flag set in the former TE-PATH- the former binding value (with R flag set in the former TE-PATH-
BINDING TLV) and include a new TE-PATH-BINDING TLV containing the new BINDING TLV) and include a new TE-PATH-BINDING TLV containing the new
binding value. binding value.
In some cases, a stateful PCE can request the PCC to allocate any In some cases, a stateful PCE may want to request that the PCC
binding value. It instructs the PCC by sending a PCUpd message allocate a binding value of the PCC's own choosing. It instructs the
containing an empty TE-PATH-BINDING TLV, i.e., no binding value is PCC by sending a PCUpd message containing an empty TE-PATH-BINDING
specified (bringing the Length field of the TLV to 4). A PCE can TLV, i.e., no binding value is specified (bringing the Length field
also request a PCC to allocate a binding value at the time of of the TLV to 4). A PCE can also request a PCC to allocate a binding
initiation by sending a PCInitiate message with an empty TE-PATH- value at the time of initiation by sending a PCInitiate message with
BINDING TLV. Only one such instance of empty TE-PATH-BINDING TLV an empty TE-PATH-BINDING TLV. Only one such instance of empty TE-
SHOULD be included in the LSP object and others ignored on receipt. PATH-BINDING TLV SHOULD be included in the LSP object and others
If the PCC is unable to allocate a new binding value as per the ignored on receipt. If the PCC is unable to allocate a new binding
specified BT, it MUST send a PCErr message with Error-Type = TBD2 value as per the specified BT, it MUST send a PCErr message with
("Binding label/SID failure") and Error-Value = TBD5 ("Unable to Error-Type = TBD2 ("Binding label/SID failure") and Error-Value =
allocate a new binding label/SID"). TBD5 ("Unable to allocate a new binding label/SID").
As previously noted, if a message contains an invalid TE-PATH-BINDING As previously noted, if a message contains an invalid TE-PATH-BINDING
TLV that leads to an error condition, the whole message is rejected TLV that leads to an error condition, the whole message is rejected
including any other valid instances of TE-PATH-BINDING TLVs, if any. including any other valid instances of TE-PATH-BINDING TLVs, if any.
The resulting error message MAY include the offending TE-PATH-BINDING The resulting error message MAY include the offending TE-PATH-BINDING
TLV in the PCEP-ERROR object. TLV in the PCEP-ERROR object.
If a PCC receives a TE-PATH-BINDING TLV in any message other than If a PCC receives a TE-PATH-BINDING TLV in any message other than
PCUpd or PCInitiate, it MUST close the corresponding PCEP session PCUpd or PCInitiate, it MUST close the corresponding PCEP session
with the reason "Reception of a malformed PCEP message" (according to with the reason "Reception of a malformed PCEP message" (according to
skipping to change at page 10, line 44 skipping to change at page 10, line 44
binding values were reported before, the PCE MUST assume that the binding values were reported before, the PCE MUST assume that the
corresponding LSP does not have any binding. Similarly, if TE-PATH- corresponding LSP does not have any binding. Similarly, if TE-PATH-
BINDING TLV is absent in the PCUpd message and no binding values were BINDING TLV is absent in the PCUpd message and no binding values were
reported before, the PCC's local policy dictates how the binding reported before, the PCC's local policy dictates how the binding
allocations are made for a given LSP. allocations are made for a given LSP.
6. Binding SID in SR-ERO 6. Binding SID in SR-ERO
In PCEP messages, LSP route information is carried in the Explicit In PCEP messages, LSP route information is carried in the Explicit
Route Object (ERO), which consists of a sequence of subobjects. Route Object (ERO), which consists of a sequence of subobjects.
[RFC8664] defines a new ERO subobject "SR-ERO subobject" capable of [RFC8664] defines the "SR-ERO subobject" capable of carrying a SID as
carrying a SID as well as the identity of the node/adjacency (NAI) well as the identity of the node/adjacency (NAI) represented by the
represented by the SID. The NAI Type (NT) field indicates the type SID. The NAI Type (NT) field indicates the type and format of the
and format of the NAI contained in the SR-ERO. In case of binding NAI contained in the SR-ERO. In case of binding SID, the NAI MUST
SID, the NAI MUST NOT be included and NT MUST be set to zero. So as NOT be included and NT MUST be set to zero. [RFC8664] Section 5.2.1
per Section 5.2.1 of [RFC8664], for NT=0, the F bit is set to 1, the specifies bit settings and error handling in the case when NT=0.
S bit needs to be zero and the Length is 8. Further, the M bit is
set. If these conditions are not met, the entire ERO MUST be
considered invalid and a PCErr message is sent by the PCC with Error-
Type = 10 ("Reception of an invalid object") and Error-Value = 11
("Malformed object").
7. Binding SID in SRv6-ERO 7. Binding SID in SRv6-ERO
[I-D.ietf-pce-segment-routing-ipv6] defines a new ERO subobject [I-D.ietf-pce-segment-routing-ipv6] defines the "SRv6-ERO subobject"
"SRv6-ERO subobject" for an SRv6 SID. As stated in Section 6, in for an SRv6 SID. Similarly to SR-ERO (Section 6), the NAI MUST NOT
case of binding SID, the NAI is not included and NT is set to zero be included and the NT MUST be set to zero. [RFC8664] Section 5.2.1
i.e., NT=0, the F bit is set to 1, the S bit needs to be zero and the specifies bit settings and error handling in the case when NT=0.
Length is 24 [I-D.ietf-pce-segment-routing-ipv6]. As per [RFC8664],
if these conditions are not met, the entire ERO is considered invalid
and a PCErr message is sent by the PCC with Error-Type = 10
("Reception of an invalid object") and Error-Value = 11 ("Malformed
object").
8. PCE Allocation of Binding label/SID 8. PCE Allocation of Binding label/SID
Section 5 already includes the scenario where a PCE requires a PCC to Section 5 already includes the scenario where a PCE requires a PCC to
allocate a specified binding value by sending a PCUpd or PCInitiate allocate a specified binding value by sending a PCUpd or PCInitiate
message containing a TE-PATH-BINDING TLV. This section specifies an message containing a TE-PATH-BINDING TLV. This section specifies an
OPTIONAL feature for the PCE to allocate the binding label/SID of its OPTIONAL feature for the PCE to allocate the binding label/SID of its
own accord in the case where the PCE also controls the label space of own accord in the case where the PCE also controls the label space of
the PCC and can make the label allocation on its own as described in the PCC and can make the label allocation on its own as described in
[RFC8283]. Note that the act of requesting a specific binding value [RFC8283]. Note that the act of requesting a specific binding value
(Section 5) is different from the act of allocating a binding label/ (Section 5) is different from the act of allocating a binding label/
SID as described in this section. SID as described in this section.
[RFC8283] introduces the architecture for PCE as a central controller [RFC8283] introduces the architecture for PCE as a central controller
as an extension of the architecture described in [RFC4655] and as an extension of the architecture described in [RFC4655] and
assumes the continued use of PCEP as the protocol used between PCE assumes the continued use of PCEP as the protocol used between PCE
and PCC. [I-D.ietf-pce-pcep-extension-for-pce-controller] specifies and PCC. [RFC9050] specifies the procedures and PCEP extensions for
the procedures and PCEP extensions for using the PCE as the central using the PCE as the central controller.
controller.
For an implementation that supports PCECC operations as per When PCECC operations are supported as per [RFC9050], the binding
[I-D.ietf-pce-pcep-extension-for-pce-controller], the binding label/ label/SID MAY also be allocated by the PCE itself. Both peers need
SID MAY also be allocated by the PCE itself. Both peers need to to exchange the PCECC capability as described in [RFC9050] before the
exchange the PCECC capability as described in PCE can allocate the binding label/SID on its own.
[I-D.ietf-pce-pcep-extension-for-pce-controller] before the PCE can
allocate the binding label/SID on its own.
A new P flag in the LSP object [RFC8231] is introduced to indicate A new P flag in the LSP object [RFC8231] is introduced to indicate
the allocation needs to be made by the PCE: that the allocation needs to be made by the PCE:
o P (PCE-allocated binding label/SID): If the bit is set to 1, it o P (PCE-allocated binding label/SID): If the bit is set to 1, it
indicates that the PCC requests PCE to make allocations for this indicates that the PCC requests PCE to make allocations for this
LSP. The TE-PATH-BINDING TLV in the LSP object identifies that LSP. The TE-PATH-BINDING TLV in the LSP object identifies that
the allocation is for binding label/SID. A PCC MUST set this bit the allocation is for a binding label/SID. A PCC MUST set this
to 1 and include a TE-PATH-BINDING TLV in the LSP object to bit to 1 and include a TE-PATH-BINDING TLV in the LSP object if it
request for allocation of binding label/SID by the PCE in the PCEP wishes to request for allocation of binding label/SID by the PCE
message. A PCE MUST also set this bit to 1 and include a TE-PATH- in the PCEP message. A PCE MUST also set this bit to 1 and
BINDING TLV to indicate that the binding label/SID is allocated by include a TE-PATH-BINDING TLV to indicate that the binding label/
PCE and encoded in the PCEP message towards the PCC. Further, a SID is allocated by PCE and encoded in the PCEP message towards
PCE MUST set this bit to 0 and include a TE-PATH-BINDING TLV in the PCC. Further, a PCE MUST set this bit to 0 and include a TE-
the LSP object to indicate that the binding label/SID should be PATH-BINDING TLV in the LSP object if it wishes to indicate that
allocated by the PCC as described in Section 5. the binding label/SID should be allocated by the PCC as described
in Section 5.
Note that - Note that -
o A PCE could allocate the binding label/SID of its own accord for a o A PCE could allocate the binding label/SID of its own accord for a
PCE-initiated or delegated LSP, and inform the PCC in the PCE-initiated or delegated LSP, and inform the PCC in the
PCInitiate message or PCUpd message by setting P=1 and including PCInitiate message or PCUpd message by setting P=1 and including
TE-PATH-BINDING TLV in the LSP object. TE-PATH-BINDING TLV in the LSP object.
o To let the PCC allocates the binding label/SID, a PCE MUST set P=0 o To let the PCC allocate the binding label/SID, a PCE MUST set P=0
and include an empty TE-PATH-BINDING TLV ( i.e., no binding value and include an empty TE-PATH-BINDING TLV ( i.e., no binding value
is specified) in the LSP object in PCInitiate/PCUpd message. is specified) in the LSP object in PCInitiate/PCUpd message.
o To request that the PCE allocate the binding label/SID, a PCC MUST o To request that the PCE allocate the binding label/SID, a PCC MUST
set P=1, D=1, and include an empty TE-PATH-BINDING TLV in PCRpt set P=1, D=1, and include an empty TE-PATH-BINDING TLV in PCRpt
message. The PCE SHOULD allocate it and respond to the PCC with message. The PCE SHOULD allocate it and respond to the PCC with
PCUpd message including the allocated binding label/SID in the TE- PCUpd message including the allocated binding label/SID in the TE-
PATH-BINDING TLV and P=1, D=1 in the LSP object. If the PCE is PATH-BINDING TLV and P=1, D=1 in the LSP object. If the PCE is
unable to allocate, it MUST send a PCErr message with Error-Type = unable to allocate, it MUST send a PCErr message with Error-Type =
TBD2 ("Binding label/SID failure") and Error-Value = TBD5 ("Unable TBD2 ("Binding label/SID failure") and Error-Value = TBD5 ("Unable
to allocate a new binding label/SID"). to allocate a new binding label/SID").
o If both peers have not exchanged the PCECC capabilities as per o If one or both speakers (PCE and PCC) have not indicated support
[I-D.ietf-pce-pcep-extension-for-pce-controller] and a PCEP peer and willingness to use the PCEP extensions for the PCECC as per
receives P=1 in the LSP object, it needs to act as per [RFC9050] and a PCEP peer receives P=1 in the LSP object, it MUST:
[I-D.ietf-pce-pcep-extension-for-pce-controller]:
* Send a PCErr message with Error-Type=19 (Invalid Operation) and * send a PCErr message with Error-Type=19 (Invalid Operation) and
Error-Value=16 (Attempted PCECC operations when PCECC Error-value=16 (Attempted PCECC operations when PCECC
capability was not advertised) capability was not advertised) and
* Terminate the PCEP session * terminate the PCEP session.
o A legacy PCEP speaker that does not recognize the P flag in the
LSP object would ignore it in accordance with [RFC8231].
It is assumed that the label range to be used by a PCE is known and It is assumed that the label range to be used by a PCE is known and
set on both PCEP peers. The exact mechanism is out of the scope of set on both PCEP peers. The exact mechanism is out of the scope of
[I-D.ietf-pce-pcep-extension-for-pce-controller] or this document. [RFC9050] or this document. Note that the specific BSID could be
Note that the specific BSID could be from the PCE-controlled or the from the PCE-controlled or the PCC-controlled label space. The PCE
PCC-controlled label space. The PCE can directly allocate the label can directly allocate the label from the PCE-controlled label space
from the PCE-controlled label space using P=1 as described above, using P=1 as described above, whereas the PCE can request the
whereas the PCE can request for the allocation of a specific BSID allocation of a specific BSID from the PCC-controlled label space
from the PCC-controlled label space with P=0 as described in with P=0 as described in Section 5.
Section 5.
9. Implementation Status 9. Implementation Status
[Note to the RFC Editor - remove this section before publication, as [Note to the RFC Editor - remove this section before publication, as
well as remove the reference to RFC 7942.] well as remove the reference to RFC 7942.]
This section records the status of known implementations of the This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in [RFC7942]. Internet-Draft, and is based on a proposal described in [RFC7942].
The description of implementations in this section is intended to The description of implementations in this section is intended to
assist the IETF in its decision processes in progressing drafts to assist the IETF in its decision processes in progressing drafts to
RFCs. Please note that the listing of any individual implementation RFCs. Please note that the listing of any individual implementation
here does not imply endorsement by the IETF. Furthermore, no effort here does not imply endorsement by the IETF. Furthermore, no effort
has been spent to verify the information presented here that was has been spent to verify the information presented here that was
supplied by IETF contributors. This is not intended as, and must not supplied by IETF contributors. This is not intended as, and must not
be construed to be, a catalog of available implementations or their be construed to be, a catalog of available implementations or their
features. Readers are advised to note that other implementations may features. Readers are advised to note that other implementations may
exist. exist.
skipping to change at page 14, line 20 skipping to change at page 14, line 11
o Coverage: Full o Coverage: Full
o Contact: mkoldych@cisco.com o Contact: mkoldych@cisco.com
10. Security Considerations 10. Security Considerations
The security considerations described in [RFC5440], [RFC8231], The security considerations described in [RFC5440], [RFC8231],
[RFC8281] and [RFC8664] are applicable to this specification. No [RFC8281] and [RFC8664] are applicable to this specification. No
additional security measure is required. additional security measure is required.
As described [RFC8664], SR allows a network controller to instantiate As described in [RFC8664], SR allows a network controller to
and control paths in the network. A rogue PCE can manipulate binding instantiate and control paths in the network. A rogue PCE can
SID allocations to move traffic around for some other LSP that uses manipulate binding SID allocations to move traffic around for some
BSID in its SR-ERO. other LSP that uses BSID in its SR-ERO. Note that path {A, B, BSID}
can be misdirected just by assigning the BSID value to a different
LSP making it a lot easier to misdirect traffic (and harder to
detect).
Note that in case of BT as 3, the manipulation of SID structure could
be exploited by falsifying the various length values.
Thus, as per [RFC8231], it is RECOMMENDED that these PCEP extensions Thus, as per [RFC8231], it is RECOMMENDED that these PCEP extensions
only be activated on authenticated and encrypted sessions across PCEs only be activated on authenticated and encrypted sessions across PCEs
and PCCs belonging to the same administrative authority, using and PCCs belonging to the same administrative authority, using
Transport Layer Security (TLS) [RFC8253], as per the recommendations Transport Layer Security (TLS) [RFC8253], as per the recommendations
and best current practices in BCP195 [RFC7525] (unless explicitly set and best current practices in BCP195 [RFC7525] (unless explicitly set
aside in [RFC8253]). aside in [RFC8253]).
11. Manageability Considerations 11. Manageability Considerations
All manageability requirements and considerations listed in All manageability requirements and considerations listed in
[RFC5440], [RFC8231], and [RFC8664] apply to PCEP protocol extensions [RFC5440], [RFC8231], and [RFC8664] apply to PCEP protocol extensions
defined in this document. In addition, requirements and defined in this document. In addition, requirements and
considerations listed in this section apply. considerations listed in this section apply.
11.1. Control of Function and Policy 11.1. Control of Function and Policy
A PCC implementation SHOULD allow the operator to configure the A PCC implementation SHOULD allow the operator to configure the
policy the PCC needs to apply when allocating the binding label/SID. policy the PCC needs to apply when allocating the binding label/SID.
For BT is 2, the operator needs to have local policy set to decide
the SID structure and the SRv6 Endpoint Behavior of the BSID.
11.2. Information and Data Models 11.2. Information and Data Models
The PCEP YANG module [I-D.ietf-pce-pcep-yang] could be extended to The PCEP YANG module [I-D.ietf-pce-pcep-yang] will be extended to
include policy configuration for binding label/SID allocation. include policy configuration for binding label/SID allocation.
11.3. Liveness Detection and Monitoring 11.3. Liveness Detection and Monitoring
The mechanisms defined in this document do not imply any new liveness The mechanisms defined in this document do not imply any new liveness
detection and monitoring requirements in addition to those already detection and monitoring requirements in addition to those already
listed in [RFC5440]. listed in [RFC5440].
11.4. Verify Correct Operations 11.4. Verify Correct Operations
skipping to change at page 15, line 25 skipping to change at page 15, line 25
listed in [RFC5440], [RFC8231], and [RFC8664]. listed in [RFC5440], [RFC8231], and [RFC8664].
11.5. Requirements On Other Protocols 11.5. Requirements On Other Protocols
The mechanisms defined in this document do not imply any new The mechanisms defined in this document do not imply any new
requirements on other protocols. requirements on other protocols.
11.6. Impact On Network Operations 11.6. Impact On Network Operations
The mechanisms defined in [RFC5440], [RFC8231], and [RFC8664] also The mechanisms defined in [RFC5440], [RFC8231], and [RFC8664] also
apply to the PCEP extensions defined in this document. Further, the apply to the PCEP extensions defined in this document.
mechanism described in this document can help the operator to request
control of the LSPs at a particular PCE.
12. IANA Considerations 12. IANA Considerations
IANA maintains the "Path Computation Element Protocol (PCEP) Numbers" IANA maintains the "Path Computation Element Protocol (PCEP) Numbers"
registry. This document requests IANA actions to allocate code registry. This document requests IANA actions to allocate code
points for the protocol elements defined in this document. points for the protocol elements defined in this document.
12.1. PCEP TLV Type Indicators 12.1. PCEP TLV Type Indicators
This document defines a new PCEP TLV; IANA is requested to confirm This document defines a new PCEP TLV; IANA is requested to confirm
skipping to change at page 16, line 45 skipping to change at page 16, line 45
point in the "LSP Object Flag Field" sub-registry for the new P flag point in the "LSP Object Flag Field" sub-registry for the new P flag
as follows: as follows:
Bit Description Reference Bit Description Reference
0 PCE-allocated binding This document 0 PCE-allocated binding This document
label/SID label/SID
12.3. PCEP Error Type and Value 12.3. PCEP Error Type and Value
This document defines a new Error-type and Error-Values for the PCErr This document defines a new Error-type and associated Error-Values
message. IANA is requested to allocate new error-type and error- for the PCErr message. IANA is requested to allocate new error-type
values within the "PCEP-ERROR Object Error Types and Values" and error-values within the "PCEP-ERROR Object Error Types and
subregistry of the PCEP Numbers registry, as follows: Values" subregistry of the PCEP Numbers registry, as follows:
Error-Type Meaning Error-value Reference Error-Type Meaning Error-value Reference
TBD2 Binding label/SID 0: Unassigned This TBD2 Binding label/SID 0: Unassigned This
failure document failure document
TBD3: Invalid SID This TBD3: Invalid SID This
document document
TBD4: Unable to allocate the This TBD4: Unable to allocate the This
specified binding value document specified binding value document
TBD5: Unable to allocate a This TBD5: Unable to allocate a This
new binding label/SID document new binding label/SID document
13. Acknowledgements 13. Acknowledgements
We like to thank Milos Fabian, Mrinmoy Das, Andrew Stone, Tom Petch, We would like to thank Milos Fabian, Mrinmoy Das, Andrew Stone, Tom
Aijun Wang, Olivier Dugeon, and Adrian Farrel for their valuable Petch, Aijun Wang, Olivier Dugeon, and Adrian Farrel for their
comments. valuable comments.
Thanks to Julien Meuric for shepherding. Thanks to John Scudder for
the AD review.
14. References 14. References
14.1. Normative References 14.1. 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, 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 19, line 5 skipping to change at page 19, line 11
Writing an IANA Considerations Section in RFCs", BCP 26, Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017, RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>. <https://www.rfc-editor.org/info/rfc8126>.
[RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer, [RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer,
D., Matsushima, S., and Z. Li, "Segment Routing over IPv6 D., Matsushima, S., and Z. Li, "Segment Routing over IPv6
(SRv6) Network Programming", RFC 8986, (SRv6) Network Programming", RFC 8986,
DOI 10.17487/RFC8986, February 2021, DOI 10.17487/RFC8986, February 2021,
<https://www.rfc-editor.org/info/rfc8986>. <https://www.rfc-editor.org/info/rfc8986>.
[I-D.ietf-pce-pcep-extension-for-pce-controller] [RFC9050] Li, Z., Peng, S., Negi, M., Zhao, Q., and C. Zhou, "Path
Li, Z., Peng, S., Negi, M. S., Zhao, Q., and C. Zhou, Computation Element Communication Protocol (PCEP)
"PCEP Procedures and Protocol Extensions for Using PCE as Procedures and Extensions for Using the PCE as a Central
a Central Controller (PCECC) of LSPs", draft-ietf-pce- Controller (PCECC) of LSPs", RFC 9050,
pcep-extension-for-pce-controller-14 (work in progress), DOI 10.17487/RFC9050, July 2021,
March 2021. <https://www.rfc-editor.org/info/rfc9050>.
[I-D.ietf-pce-segment-routing-ipv6] [I-D.ietf-pce-segment-routing-ipv6]
Li, C., Negi, M., Sivabalan, S., Koldychev, M., Li, C., Negi, M., Sivabalan, S., Koldychev, M.,
Kaladharan, P., and Y. Zhu, "PCEP Extensions for Segment Kaladharan, P., and Y. Zhu, "PCEP Extensions for Segment
Routing leveraging the IPv6 data plane", draft-ietf-pce- Routing leveraging the IPv6 data plane", draft-ietf-pce-
segment-routing-ipv6-09 (work in progress), May 2021. segment-routing-ipv6-09 (work in progress), May 2021.
14.2. Informative References 14.2. Informative References
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation [RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
skipping to change at page 19, line 40 skipping to change at page 19, line 46
[RFC8669] Previdi, S., Filsfils, C., Lindem, A., Ed., Sreekantiah, [RFC8669] Previdi, S., Filsfils, C., Lindem, A., Ed., Sreekantiah,
A., and H. Gredler, "Segment Routing Prefix Segment A., and H. Gredler, "Segment Routing Prefix Segment
Identifier Extensions for BGP", RFC 8669, Identifier Extensions for BGP", RFC 8669,
DOI 10.17487/RFC8669, December 2019, DOI 10.17487/RFC8669, December 2019,
<https://www.rfc-editor.org/info/rfc8669>. <https://www.rfc-editor.org/info/rfc8669>.
[I-D.ietf-spring-segment-routing-policy] [I-D.ietf-spring-segment-routing-policy]
Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and
P. Mattes, "Segment Routing Policy Architecture", draft- P. Mattes, "Segment Routing Policy Architecture", draft-
ietf-spring-segment-routing-policy-11 (work in progress), ietf-spring-segment-routing-policy-13 (work in progress),
April 2021. May 2021.
[I-D.ietf-pce-pcep-yang] [I-D.ietf-pce-pcep-yang]
Dhody, D., Hardwick, J., Beeram, V. P., and J. Tantsura, Dhody, D., Hardwick, J., Beeram, V. P., and J. Tantsura,
"A YANG Data Model for Path Computation Element "A YANG Data Model for Path Computation Element
Communications Protocol (PCEP)", draft-ietf-pce-pcep- Communications Protocol (PCEP)", draft-ietf-pce-pcep-
yang-16 (work in progress), February 2021. yang-16 (work in progress), February 2021.
Appendix A. Contributor Addresses Appendix A. Contributor Addresses
Jonathan Hardwick Jonathan Hardwick
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