< draft-ietf-pce-segment-routing-10.txt   draft-ietf-pce-segment-routing-11.txt >
PCE S. Sivabalan PCE S. Sivabalan
Internet-Draft C. Filsfils Internet-Draft C. Filsfils
Intended status: Standards Track Cisco Systems, Inc. Intended status: Standards Track Cisco Systems, Inc.
Expires: April 13, 2018 J. Tantsura Expires: May 24, 2018 J. Tantsura
Individual Individual
W. Henderickx W. Henderickx
Nokia Nokia
J. Hardwick J. Hardwick
Metaswitch Networks Metaswitch Networks
October 10, 2017 November 20, 2017
PCEP Extensions for Segment Routing PCEP Extensions for Segment Routing
draft-ietf-pce-segment-routing-10 draft-ietf-pce-segment-routing-11
Abstract Abstract
Segment Routing (SR) enables any head-end node to select any path Segment Routing (SR) enables any head-end node to select any path
without relying on a hop-by-hop signaling technique (e.g., LDP or without relying on a hop-by-hop signaling technique (e.g., LDP or
RSVP-TE). It depends only on "segments" that are advertised by Link- RSVP-TE). It depends only on "segments" that are advertised by Link-
State Interior Gateway Protocols (IGPs). A Segment Routed Path can State Interior Gateway Protocols (IGPs). A Segment Routed Path can
be derived from a variety of mechanisms, including an IGP Shortest be derived from a variety of mechanisms, including an IGP Shortest
Path Tree (SPT), explicit configuration, or a Path Computation Path Tree (SPT), explicit configuration, or a Path Computation
Element (PCE). This document specifies extensions to the Path Element (PCE). This document specifies extensions to the Path
skipping to change at page 1, line 45 skipping to change at page 1, line 45
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
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
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Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
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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 April 13, 2018. This Internet-Draft will expire on May 24, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Overview of PCEP Operation in SR Networks . . . . . . . . . . 5 3. Overview of PCEP Operation in SR Networks . . . . . . . . . . 5
4. SR-Specific PCEP Message Extensions . . . . . . . . . . . . . 6 4. SR-Specific PCEP Message Extensions . . . . . . . . . . . . . 6
5. Object Formats . . . . . . . . . . . . . . . . . . . . . . . 7 5. Object Formats . . . . . . . . . . . . . . . . . . . . . . . 7
5.1. The OPEN Object . . . . . . . . . . . . . . . . . . . . . 7 5.1. The OPEN Object . . . . . . . . . . . . . . . . . . . . . 7
5.1.1. The SR PCE Capability TLV . . . . . . . . . . . . . . 7 5.1.1. The SR PCE Capability sub-TLV . . . . . . . . . . . . 7
5.2. The RP/SRP Object . . . . . . . . . . . . . . . . . . . . 8 5.1.2. Exchanging the SR PCE Capability . . . . . . . . . . 8
5.2. The RP/SRP Object . . . . . . . . . . . . . . . . . . . . 9
5.3. ERO Object . . . . . . . . . . . . . . . . . . . . . . . 9 5.3. ERO Object . . . . . . . . . . . . . . . . . . . . . . . 9
5.3.1. SR-ERO Subobject . . . . . . . . . . . . . . . . . . 9 5.3.1. SR-ERO Subobject . . . . . . . . . . . . . . . . . . 10
5.3.2. NAI Associated with SID . . . . . . . . . . . . . . . 11 5.3.2. NAI Associated with SID . . . . . . . . . . . . . . . 12
5.3.3. ERO Processing . . . . . . . . . . . . . . . . . . . 12 5.3.3. ERO Processing . . . . . . . . . . . . . . . . . . . 13
5.4. RRO Object . . . . . . . . . . . . . . . . . . . . . . . 13 5.4. RRO Object . . . . . . . . . . . . . . . . . . . . . . . 14
5.4.1. RRO Processing . . . . . . . . . . . . . . . . . . . 14 5.4.1. RRO Processing . . . . . . . . . . . . . . . . . . . 14
5.5. METRIC Object . . . . . . . . . . . . . . . . . . . . . . 14 5.5. METRIC Object . . . . . . . . . . . . . . . . . . . . . . 15
6. Backward Compatibility . . . . . . . . . . . . . . . . . . . 15 6. Backward Compatibility . . . . . . . . . . . . . . . . . . . 15
7. Management Considerations . . . . . . . . . . . . . . . . . . 15 7. Management Considerations . . . . . . . . . . . . . . . . . . 16
7.1. Policy . . . . . . . . . . . . . . . . . . . . . . . . . 15 7.1. Policy . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.2. The PCEP Data Model . . . . . . . . . . . . . . . . . . . 15 7.2. The PCEP Data Model . . . . . . . . . . . . . . . . . . . 16
8. Security Considerations . . . . . . . . . . . . . . . . . . . 15 8. Security Considerations . . . . . . . . . . . . . . . . . . . 16
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
9.1. PCEP Objects . . . . . . . . . . . . . . . . . . . . . . 16 9.1. PCEP Objects . . . . . . . . . . . . . . . . . . . . . . 16
9.2. PCEP-Error Object . . . . . . . . . . . . . . . . . . . . 16 9.2. PCEP-Error Object . . . . . . . . . . . . . . . . . . . . 17
9.3. PCEP TLV Type Indicators . . . . . . . . . . . . . . . . 17 9.3. PCEP TLV Type Indicators . . . . . . . . . . . . . . . . 18
9.4. New Path Setup Type . . . . . . . . . . . . . . . . . . . 17 9.4. New Path Setup Type . . . . . . . . . . . . . . . . . . . 18
9.5. New Metric Type . . . . . . . . . . . . . . . . . . . . . 17 9.5. New Metric Type . . . . . . . . . . . . . . . . . . . . . 18
10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 18
10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 17 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 19
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 18 12.1. Normative References . . . . . . . . . . . . . . . . . . 19
12.1. Normative References . . . . . . . . . . . . . . . . . . 18 12.2. Informative References . . . . . . . . . . . . . . . . . 20
12.2. Informative References . . . . . . . . . . . . . . . . . 19 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20
1. Introduction 1. Introduction
SR technology leverages the source routing and tunneling paradigms. SR technology leverages the source routing and tunneling paradigms.
A source node can choose a path without relying on hop-by-hop A source node can choose a path without relying on hop-by-hop
signaling protocols such as LDP or RSVP-TE. Each path is specified signaling protocols such as LDP or RSVP-TE. Each path is specified
as a set of "segments" advertised by link-state routing protocols as a set of "segments" advertised by link-state routing protocols
(IS-IS or OSPF). [I-D.ietf-spring-segment-routing] provides an (IS-IS or OSPF). [I-D.ietf-spring-segment-routing] provides an
introduction to SR architecture. The corresponding IS-IS and OSPF introduction to SR architecture. The corresponding IS-IS and OSPF
extensions are specified in extensions are specified in
[I-D.ietf-isis-segment-routing-extensions] and [I-D.ietf-isis-segment-routing-extensions] and
[I-D.ietf-ospf-segment-routing-extensions], respectively. SR [I-D.ietf-ospf-segment-routing-extensions], respectively. SR
architecture defines a "segment" as a piece of information advertised architecture defines a "segment" as a piece of information advertised
by a link-state routing protocols, e.g. an IGP prefix or an IGP by a link-state routing protocols, e.g. an IGP prefix or an IGP
adjacency. Several types of segments are defined. A Node segment adjacency. Several types of segments are defined. A Node segment
represents an ECMP-aware shortest-path computed by IGP to a specific represents an ECMP-aware shortest-path computed by IGP to a specific
node, and is always global within SR/IGP domain. An Adjacency node, and is always global within SR/IGP domain. An Adjacency
Segment represents unidirectional adjacency. An Adjacency Segment is Segment represents a unidirectional adjacency. An Adjacency Segment
local to the node which advertises it. Both Node segments and is local to the node which advertises it. Both Node segments and
Adjacency segments can be used for SR Traffic Engineering (SR-TE). Adjacency segments can be used for SR Traffic Engineering (SR-TE).
The SR architecture can be applied to the MPLS forwarding plane The SR architecture can be applied to the MPLS forwarding plane
without any change, in which case an SR path corresponds to an MPLS without any change, in which case an SR path corresponds to an MPLS
Label Switching Path (LSP). This document is relevant to MPLS Label Switching Path (LSP). This document is relevant to the MPLS
forwarding plane only and assumes that a 32-bit Segment Identifier forwarding plane only. In this document, "Node-SID" and "Adjacency-
(SID) represents an absolute value of MPLS label entry. In this SID" denote Node Segment Identifier and Adjacency Segment Identifier
document, "Node-SID" and "Adjacency-SID" denote Node Segment respectively.
Identifier and Adjacency Segment Identifier respectively.
A Segment Routed path (SR path) can be derived from an IGP Shortest A Segment Routed path (SR path) can be derived from an IGP Shortest
Path Tree (SPT). SR-TE paths may not follow IGP SPT. Such paths may Path Tree (SPT). SR-TE paths may not follow an IGP SPT. Such paths
be chosen by a suitable network planning tool and provisioned on the may be chosen by a suitable network planning tool and provisioned on
ingress node of the SR-TE path. the ingress node of the SR-TE path.
[RFC5440] describes Path Computation Element Protocol (PCEP) for [RFC5440] describes the Path Computation Element Protocol (PCEP) for
communication between a Path Computation Client (PCC) and a Path communication between a Path Computation Client (PCC) and a Path
Computation Element (PCE) or between one a pair of PCEs. A PCE or a Computation Element (PCE) or between a pair of PCEs. A PCE, or a PCC
PCC operating as a PCE (in hierarchical PCE environment) computes operating as a PCE (in hierarchical PCE environment), computes paths
paths for MPLS Traffic Engineering LSPs (MPLS-TE LSPs) based on for MPLS Traffic Engineering LSPs (MPLS-TE LSPs) based on various
various constraints and optimization criteria. constraints and optimization criteria. [RFC8231] specifies
[I-D.ietf-pce-stateful-pce] specifies extensions to PCEP that allow a extensions to PCEP that allow a stateful PCE to compute and recommend
stateful PCE to compute and recommend network paths in compliance network paths in compliance with [RFC4657] and defines objects and
with [RFC4657] and defines objects and TLVs for MPLS-TE LSPs. TLVs for MPLS-TE LSPs. Stateful PCEP extensions provide
Stateful PCEP extensions provide synchronization of LSP state between synchronization of LSP state between a PCC and a PCE or between a
a PCC and a PCE or between a pair of PCEs, delegation of LSP control, pair of PCEs, delegation of LSP control, reporting of LSP state from
reporting of LSP state from a PCC to a PCE, controlling the setup and a PCC to a PCE, controlling the setup and path routing of an LSP from
path routing of an LSP from a PCE to a PCC. Stateful PCEP extensions a PCE to a PCC. Stateful PCEP extensions are intended for an
are intended for an operational model in which LSPs are configured on operational model in which LSPs are configured on the PCC, and
the PCC, and control over them is delegated to the PCE. control over them is delegated to the PCE.
A mechanism to dynamically initiate LSPs on a PCC based on the A mechanism to dynamically initiate LSPs on a PCC based on the
requests from a stateful PCE or a controller using stateful PCE is requests from a stateful PCE or a controller using stateful PCE is
specified in [I-D.ietf-pce-pce-initiated-lsp]. Such mechanism is specified in [I-D.ietf-pce-pce-initiated-lsp]. This mechanism is
useful in Software Driven Networks (SDN) applications, such as on useful in Software Defined Networking (SDN) applications, such as on-
demand engineering, or bandwidth calendaring. demand engineering, or bandwidth calendaring.
It is possible to use a stateful PCE for computing one or more SR-TE It is possible to use a stateful PCE for computing one or more SR-TE
paths taking into account various constraints and objective paths taking into account various constraints and objective
functions. Once a path is chosen, the stateful PCE can initiate an functions. Once a path is chosen, the stateful PCE can initiate an
SR-TE path on a PCC using PCEP extensions specified in SR-TE path on a PCC using PCEP extensions specified in
[I-D.ietf-pce-pce-initiated-lsp] using the SR specific PCEP [I-D.ietf-pce-pce-initiated-lsp] using the SR specific PCEP
extensions specified in this document. Additionally, using extensions specified in this document. Additionally, using
procedures described in this document, a PCC can request an SR path procedures described in this document, a PCC can request an SR path
from either stateful or a stateless PCE. This specification relies from either stateful or a stateless PCE. This specification relies
on the PATH-SETUP-TYPE TLV and procedures specified in on the procedures specified in [I-D.ietf-pce-lsp-setup-type].
[I-D.ietf-pce-lsp-setup-type].
2. Terminology 2. Terminology
The following terminologies are used in this document: The following terminologies are used in this document:
ERO: Explicit Route Object ERO: Explicit Route Object
IGP: Interior Gateway Protocol IGP: Interior Gateway Protocol
IS-IS: Intermediate System to Intermediate System IS-IS: Intermediate System to Intermediate System
skipping to change at page 5, line 51 skipping to change at page 5, line 51
This document defines a new ERO subobject denoted by "SR-ERO This document defines a new ERO subobject denoted by "SR-ERO
subobject" capable of carrying a SID as well as the identity of the subobject" capable of carrying a SID as well as the identity of the
node/adjacency represented by the SID. SR-capable PCEP speakers node/adjacency represented by the SID. SR-capable PCEP speakers
should be able to generate and/or process such ERO subobject. An ERO should be able to generate and/or process such ERO subobject. An ERO
containing SR-ERO subobjects can be included in the PCEP Path containing SR-ERO subobjects can be included in the PCEP Path
Computation Reply (PCRep) message defined in [RFC5440], the PCEP LSP Computation Reply (PCRep) message defined in [RFC5440], the PCEP LSP
Initiate Request message (PCInitiate) defined in Initiate Request message (PCInitiate) defined in
[I-D.ietf-pce-pce-initiated-lsp], as well as in the PCEP LSP Update [I-D.ietf-pce-pce-initiated-lsp], as well as in the PCEP LSP Update
Request (PCUpd) and PCEP LSP State Report (PCRpt) messages defined in Request (PCUpd) and PCEP LSP State Report (PCRpt) messages defined in
defined in [I-D.ietf-pce-stateful-pce]. [RFC8231].
When a PCEP session between a PCC and a PCE is established, both PCEP When a PCEP session between a PCC and a PCE is established, both PCEP
speakers exchange their capabilites to indicate their ability to speakers exchange their capabilites to indicate their ability to
support SR-specific functionality. Furthermore, an LSP initially support SR-specific functionality.
established via RSVP-TE signaling can be updated with SR-TE path.
This capability is useful when a network is migrated from RSVP-TE to An PCE can update an LSP that is initially established via RSVP-TE
SR-TE technology. Similarly, an LSP initially created with SR-TE signaling to use an SR-TE path, by sending a PCUpd to the PCC that
signaling can be updated using RSVP-TE if necessary. delegated the LSP to it ([RFC8231]). Similarly, an LSP initially
created with an SR-TE path can be updated to use RSVP-TE signaling,
if necessary. This capability is useful when a network is migrated
from RSVP-TE to SR-TE technology.
A PCC MAY include an RRO object containing the recorded LSP in PCReq A PCC MAY include an RRO object containing the recorded LSP in PCReq
and PCRpt messages as specified in [RFC5440] and and PCRpt messages as specified in [RFC5440] and [RFC8231],
[I-D.ietf-pce-stateful-pce] respectively. This document defines a respectively. This document defines a new RRO subobject for SR
new RRO subobject for SR networks. Methods used by a PCC to record networks. The methods used by a PCC to record the SR-TE LSP are
SR-TE LSP are outside the scope of this document. outside the scope of this document.
In summary, this document: In summary, this document:
o Defines a new PCEP capability, new ERO subobject, new RRO o Defines a new ERO subobject, a new RRO subobject and new PCEP
subobject, a new TLV, and new PCEP error codes. error codes.
o Specifies how two PCEP speakers can establish a PCEP session that o Specifies how two PCEP speakers can establish a PCEP session that
can carry information about SR-TE paths. can carry information about SR-TE paths.
o Specifies processing rules of ERO subobject. o Specifies processing rules for the ERO subobject.
o Defines a new path setup type carried in the PATH-SETUP-TYPE TLV o Defines a new path setup type to be used in the PATH_SETUP_TYPE
for SR-TE LSP. and PATH_SETUP_TYPE_CAPABILITY TLVs
([I-D.ietf-pce-lsp-setup-type]).
o Defines a new sub-TLV for the PATH_SETUP_TYPE_CAPABILITY TLV.
The extensions specified in this document complement the existing The extensions specified in this document complement the existing
PCEP specifications to support SR-TE path. As such, the PCEP PCEP specifications to support SR-TE paths. As such, the PCEP
messages (e.g., Path Computation Request, Path Computation Reply, messages (e.g., Path Computation Request, Path Computation Reply,
Path Computation Report, Path Computation Update, Path Computation Path Computation Report, Path Computation Update, Path Computation
Initiate, etc.,) MUST be formatted according to [RFC5440], Initiate, etc.,) MUST be formatted according to [RFC5440], [RFC8231],
[I-D.ietf-pce-stateful-pce], [I-D.ietf-pce-pce-initiated-lsp], and [I-D.ietf-pce-pce-initiated-lsp], and any other applicable PCEP
any other applicable PCEP specifications. specifications.
4. SR-Specific PCEP Message Extensions 4. SR-Specific PCEP Message Extensions
As defined in [RFC5440], a PCEP message consists of a common header As defined in [RFC5440], a PCEP message consists of a common header
followed by a variable length body made up of mandatory and/or followed by a variable length body made up of mandatory and/or
optional objects. This document does not require any changes in the optional objects. This document does not require any changes in the
format of PCReq and PCRep messages specified in [RFC5440], PCInitiate format of the PCReq and PCRep messages specified in [RFC5440],
message specified in [I-D.ietf-pce-pce-initiated-lsp], and PCRpt and PCInitiate message specified in [I-D.ietf-pce-pce-initiated-lsp], and
PCUpd messages specified in [I-D.ietf-pce-stateful-pce]. However, PCRpt and PCUpd messages specified in [RFC8231].
PCEP messages pertaining to SR-TE LSP MUST include PATH-SETUP-TYPE
TLV in the RP or SRP object to clearly identify that SR-TE LSP is
intended. In other words, a PCEP speaker MUST not infer whether or
not a PCEP message pertains to SR-TE LSP from any other object or
TLV.
5. Object Formats 5. Object Formats
5.1. The OPEN Object 5.1. The OPEN Object
This document defines a new optional TLV for use in the OPEN Object. 5.1.1. The SR PCE Capability sub-TLV
5.1.1. The SR PCE Capability TLV This document defines a new Path Setup Type (PST) for SR, as follows:
The SR-PCE-CAPABILITY TLV is an optional TLV associated with the OPEN o PST = 1: Path is setup using Segment Routing Traffic Engineering.
Object to exchange SR capability of PCEP speakers. The format of the
SR-PCE-CAPABILITY TLV is shown in the following figure: A PCEP speaker SHOULD indicate its support of the function described
in this document by sending a PATH-SETUP-TYPE-CAPABILITY TLV in the
OPEN object with this new PST included in the PST list.
This document also defines the SR-PCE-CAPABILITY sub-TLV. PCEP
speakers use this sub-TLV to exchange information about their SR
capability. If a PCEP speaker includes PST=1 in the PST List of the
PATH-SETUP-TYPE-CAPABILITY TLV then it MUST also include the SR-PCE-
CAPABILITY sub-TLV inside the PATH-SETUP-TYPE-CAPABILITY TLV.
The format of the SR-PCE-CAPABILITY sub-TLV is shown in the following
figure:
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=TBD | Length=4 | | Type=26 | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Flags |L| MSD | | Reserved | Flags |L| MSD |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: SR-PCE-CAPABILITY TLV format Figure 1: SR-PCE-CAPABILITY sub-TLV format
The code point for the TLV type is to be defined by IANA. The TLV The code point for the TLV type is 26. The TLV length is 4 octets.
length is 4 octets.
The 32-bit value is formatted as follows. The "Maximum SID Depth" (1 The 32-bit value is formatted as follows. The "Maximum SID Depth" (1
octet) field (MSD) specifies the maximum number of SIDs (MPLS label octet) field (MSD) specifies the maximum number of SIDs (MPLS label
stack depth in context of this document) that a PCC is capable of stack depth in the context of this document) that a PCC is capable of
imposing on a packet. The "Reserved" (2 octets) field is unused, and imposing on a packet. The "Reserved" (2 octets) field is unused, and
MUST be set to zero on transmission and ignored on reception. The MUST be set to zero on transmission and ignored on reception. The
"Flags" field is 1 octect long, and this document defines the "Flags" field is 1 octect long, and this document defines the
following flag: following flag:
o L-flag: A PCC sets this flag to 1 to indicate that it does not o L-flag: A PCC sets this flag to 1 to indicate that it does not
impose any limit on MSD. impose any limit on the MSD.
5.1.1.1. Exchanging SR Capability 5.1.2. Exchanging the SR PCE Capability
By including the SR-PCE-CAPABILITY TLV in the OPEN message destined A PCC indicates that it is capable of supporting the head-end
to a PCE, a PCC indicates that it is capable of supporting the head- functions for SR-TE LSP by including the SR-PCE-CAPABILITY sub-TLV in
end functions for SR-TE LSP. By including the TLV in the OPEN the Open message that it sends to a PCE. A PCE indicates that it is
message destined to a PCC, a PCE indicates that it is capable of capable of computing SR-TE paths by including the SR-PCE-CAPABILITY
computing SR-TE paths. sub-TLV in the Open message that it sends to a PCC.
The number of SIDs that can be imposed on a packet depends on PCC's If a PCEP speaker receives a PATH-SETUP-TYPE-CAPABILITY TLV with a
data plane's capability. An MSD value MUST be non-zero otherwise the PST list containing PST=1, but the SR-PCE-CAPABILITY sub-TLV is
receiver of the SR-PCE-CAPABILITY TLV MUST assume that the sender is absent, then the PCEP speaker MUST send a PCErr message with Error-
not capable of imposing a MSD of any depth and hence is not SR-TE Type 10 (Reception of an invalid object) and Error-Value TBD1 (to be
capable. assigned by IANA) (Missing PCE-SR-CAPABILITY sub-TLV) and MUST then
close the PCEP session. If a PCEP speaker receives a PATH-SETUP-
TYPE-CAPABILITY TLV with a SR-PCE-CAPABILITY sub-TLV, but the PST
list does not contain PST=1, then the PCEP speaker MUST ignore the
SR-PCE-CAPABILITY sub-TLV.
Note that the MSD value exchanged via SR-PCE-CAPABILITY TLV indicates The number of SIDs that can be imposed on a packet depends on the
the SID/label imposition limit for the PCC node. However, if a PCE PCC's data plane's capability. If a PCC sets the L flag to 1 then
learns MSD value of a PCC node via different means, e.g routing the MSD is not used and MUST be set to zero. If a PCE receives an
protocols, as specified in: [I-D.ietf-isis-segment-routing-msd]; SR-PCE-CAPABILITY sub-TLV with the L flag set to 1 then it MUST
ignore the MSD field and MUST assume that the sender can impose a SID
stack of any depth. If a PCC sets the L flag to zero, then it sets
the MSD field to the maximum number of SIDs that it can impose on a
packet. If a PCE receives an SR-PCE-CAPABILITY sub-TLV with the L
flag and MSD both set to zero then it MUST assume that the PCC is not
capable of imposing a SID stack of any depth and hence is not SR-TE
capable, unless it learns a non-zero MSD for the PCC through some
other means.
Note that the MSD value exchanged via the SR-PCE-CAPABILITY sub-TLV
indicates the SID/label imposition limit for the PCC node. However,
if a PCE learns the MSD value of a PCC node via different means, e.g
routing protocols, as specified in:
[I-D.ietf-isis-segment-routing-msd];
[I-D.ietf-ospf-segment-routing-msd]; [I-D.ietf-ospf-segment-routing-msd];
[I-D.tantsura-idr-bgp-ls-segment-routing-msd], then it ignores the [I-D.ietf-idr-bgp-ls-segment-routing-msd], then it ignores the MSD
MSD value in the SR-PCE-CAPABILITY TLV. Furthermore, whenever a PCE value in the SR-PCE-CAPABILITY sub-TLV. Furthermore, whenever a PCE
learns MSD for a link via different means, it MUST use that value for learns the MSD for a link via different means, it MUST use that value
that link regardless of the MSD value exchanged via SR-PCE-CAPABILITY for that link regardless of the MSD value exchanged in the SR-PCE-
TLV. CAPABILITY sub-TLV.
Once an SR-capable PCEP session is established with a non-zero MSD Once an SR-capable PCEP session is established with a non-zero MSD
value, the corresponding PCE MUST NOT send SR-TE paths with number of value, the corresponding PCE MUST NOT send SR-TE paths with a number
SIDs exceeding that MSD value. If a PCC needs to modify the MSD of SIDs exceeding that MSD value. If a PCC needs to modify the MSD
value, the PCEP session MUST be closed and re-established with the value, it MUST close the PCEP session and re-establish it with the
new MSD value. If a PCEP session is established with a non-zero MSD new MSD value. If a PCEP session is established with a non-zero MSD
value, and the PCC receives an SR-TE path containing more SIDs than value, and the PCC receives an SR-TE path containing more SIDs than
specified in the MSD value, the PCC MUST send a PCErr message with specified in the MSD value, the PCC MUST send a PCErr message with
Error-Type 10 (Reception of an invalid object) and Error-Value 3 Error-Type 10 (Reception of an invalid object) and Error-Value 3
(Unsupported number of Segment ERO). If a PCEP session is (Unsupported number of Segment ERO subobjects). If a PCEP session is
established with an MSD value of zero, then the PCC MAY specify an established with an MSD value of zero, then the PCC MAY specify an
MSD for each path computation request that it sends to the PCE. MSD for each path computation request that it sends to the PCE, by
including a "maximum SID depth" metric object on the request, as
defined in Section 5.5.
The MSD value inside SR Capability TLV is meaningful only in the OPEN The L flag and MSD value inside the SR-PCE-CAPABILITY sub-TLV are
message sent from a PCC to a PCE. As such, a PCE does not need to meaningful only in the Open message sent from a PCC to a PCE. As
set MSD value in outbound message to a PCC. Similarly, a PCC ignores such, a PCE MUST set the L flag and MSD value to zero in an outbound
any MSD value received from a PCE. If a PCE receives multiple SR- message to a PCC. Similarly, a PCC MUST ignore any MSD value
PCE-CAPABILITY TLVs in an OPEN message, it processes only the first received from a PCE. If a PCE receives multiple SR-PCE-CAPABILITY
TLV received. sub-TLVs in an Open message, it processes only the first sub-TLV
received.
5.2. The RP/SRP Object 5.2. The RP/SRP Object
In order to setup an SR-TE LSP using SR, RP or SRP object MUST In order to setup an SR-TE LSP using SR, RP or SRP object MUST
include PATH-SETUP-TYPE TLV specified in include PATH-SETUP-TYPE TLV, specified in
[I-D.ietf-pce-lsp-setup-type]. This document defines a new Path [I-D.ietf-pce-lsp-setup-type], with the PST set to 1 (path setup
Setup Type (PST) for SR as follows: using SR-TE).
o PST = 1: Path is setup using Segment Routing Traffic Engineering
technique.
LSP-IDENTIFIERS TLV MAY be present for the above PST type. The LSP-IDENTIFIERS TLV MAY be present for the above PST type.
5.3. ERO Object 5.3. ERO Object
An SR-TE path consists of one or more SID(s) where each SID MAY be An SR-TE path consists of one or more SID(s) where each SID MAY be
associated with the identifier that represents the node or adjacency associated with the identifier that represents the node or adjacency
corresponding to the SID. This identifier is referred to as the corresponding to the SID. This identifier is referred to as the
'Node or Adjacency Identifier' (NAI). As described later, a NAI can 'Node or Adjacency Identifier' (NAI). As described later, a NAI can
be represented in various formats (e.g., IPv4 address, IPv6 address, be represented in various formats (e.g., IPv4 address, IPv6 address,
etc). Furthermore, a NAI is used for troubleshooting purposes and, etc). Furthermore, a NAI is used for troubleshooting purposes and,
if necessary, to derive SID value as described below. if necessary, to derive SID value as described below.
skipping to change at page 11, line 41 skipping to change at page 12, line 30
format of the NAI is shown in the following figure: format of the NAI is shown in the following figure:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local IPv4 address | | Local IPv4 address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote IPv4 address | | Remote IPv4 address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: NAI for IPv4 Adjacency Figure 3: NAI for IPv4 adjacency
'IPv6 Adjacency' is specified as a pair of IPv6 addresses. In this 'IPv6 Adjacency' is specified as a pair of IPv6 addresses. In this
case, ST valie is 4. The Length is 8, 36 or 40 depending on case, ST valie is 4. The Length is 8, 36 or 40 depending on
whether SID or NAI or both included in the subobject,and the whether SID or NAI or both included in the subobject,and the
format of the NAI is shown in the following figure: format of the NAI is shown in the following figure:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Local IPv6 address (16 bytes) // // Local IPv6 address (16 bytes) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Remote IPv6 address (16 bytes) // // Remote IPv6 address (16 bytes) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: NAI for IPv6 adjacenc y Figure 4: NAI for IPv6 adjacency
'Unnumbered Adjacency with IPv4 NodeIDs' is specified as a pair of 'Unnumbered Adjacency with IPv4 NodeIDs' is specified as a pair of
Node ID / Interface ID tuples. In this case, ST value is 5. The Node ID / Interface ID tuples. In this case, ST value is 5. The
Length is 8, 20, or 24 depending on whether SID or NAI or both Length is 8, 20, or 24 depending on whether SID or NAI or both
included in the subobject, and the format of the NAI is shown in included in the subobject, and the format of the NAI is shown in
the following figure: the following figure:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 13, line 5 skipping to change at page 13, line 39
message and MUST send a PCErr message with Error-Type=3 ("Unknown message and MUST send a PCErr message with Error-Type=3 ("Unknown
Object") and Error-Value=2 ("Unrecognized object Type") or Error- Object") and Error-Value=2 ("Unrecognized object Type") or Error-
Type=4 ("Not supported object") and Error-Value=2 ("Not supported Type=4 ("Not supported object") and Error-Value=2 ("Not supported
object Type"), defined in [RFC5440]. object Type"), defined in [RFC5440].
When the SID represents an MPLS label (i.e. the M bit is set), its When the SID represents an MPLS label (i.e. the M bit is set), its
value (20 most significant bits) MUST be larger than 15, unless it is value (20 most significant bits) MUST be larger than 15, unless it is
special purpose label, such as an Entropy Label Indicator (ELI). If special purpose label, such as an Entropy Label Indicator (ELI). If
a PCEP speaker receives an invalid value, it MUST send a PCErr a PCEP speaker receives an invalid value, it MUST send a PCErr
message with Error-Type = 10 ("Reception of an invalid object") and message with Error-Type = 10 ("Reception of an invalid object") and
Error Value = TBD ("Bad label value"). If both M and C bits of an Error Value = 2 ("Bad label value"). If both M and C bits of an SR-
SR-ERO subobject are set, and if a PCEP speaker finds erroneous ERO subobject are set, and if a PCEP speaker finds erroneous setting
setting in one or more of TC, S, and TTL fields, it MUST send a PCErr in one or more of TC, S, and TTL fields, it MUST send a PCErr message
message with Error-Type = 10 ("Reception of an invalid object") and with Error-Type = 10 ("Reception of an invalid object") and Error-
Error-Value = TBD ("Bad label format"). Value = 4 ("Bad label format").
If a PCC receives a stack of SR-ERO subobjects, and the number of If a PCC receives a stack of SR-ERO subobjects, and the number of
stack exceeds the maximum number of SIDs that the PCC can impose on stack exceeds the maximum number of SIDs that the PCC can impose on
the packet, it MAY send a PCErr message with Error-Type = 10 the packet, it MAY send a PCErr message with Error-Type = 10
("Reception of an invalid object") and Error-Value = TBD ("Reception of an invalid object") and Error-Value = 3 ("Unsupported
("Unsupported number of Segment ERO subobjects"). number of Segment ERO subobjects").
When a PCEP speaker detects that all subobjects of ERO are not When a PCEP speaker detects that all subobjects of ERO are not
identical, and if it does not handle such ERO, it MUST send a PCErr identical, and if it does not handle such ERO, it MUST send a PCErr
message with Error-Type = 10 ("Reception of an invalid object") and message with Error-Type = 10 ("Reception of an invalid object") and
Error-Value = TBD ("Non-identical ERO subobjects"). Error-Value = 5 ("Non-identical ERO subobjects").
If a PCEP speaker receives an SR-ERO subobject in which both SID and If a PCEP speaker receives an SR-ERO subobject in which both SID and
NAI are absent, it MUST consider the entire ERO object invalid and NAI are absent, it MUST consider the entire ERO object invalid and
send a PCErr message with Error-Type = 10 ("Reception of an invalid send a PCErr message with Error-Type = 10 ("Reception of an invalid
object") and Error-Value = TBD ("Both SID and NAI are absent in ERO object") and Error-Value = 6 ("Both SID and NAI are absent in ERO
subobject"). subobject").
When a PCEP speaker receives an SR-ERO subobject in which ST is 0, When a PCEP speaker receives an SR-ERO subobject in which ST is 0,
SID MUST be present and NAI MUST NOT be present(i.e., S-flag MUST be SID MUST be present and NAI MUST NOT be present(i.e., S-flag MUST be
0, F-flag MUST be 1, and the Length MUST be 8). Otherwise, it MUST 0, F-flag MUST be 1, and the Length MUST be 8). Otherwise, it MUST
consider the entire ERO object invalid and send a PCErr message with consider the entire ERO object invalid and send a PCErr message with
Error-Type = 10 ("Reception of an invalid object") and Error-Value = Error-Type = 10 ("Reception of an invalid object") and Error-Value =
TBD ("Malformed object"). The PCEP speaker MAY include the malformed 11 ("Malformed object"). The PCEP speaker MAY include the malformed
SR-ERO object in the PCErr message as well. SR-ERO object in the PCErr message as well.
5.4. RRO Object 5.4. RRO Object
A PCC can record SR-TE LSP and report the LSP to a PCE via RRO. An A PCC can record SR-TE LSP and report the LSP to a PCE via RRO. An
RRO object contains one or more subobjects called "SR-RRO subobjects" RRO object contains one or more subobjects called "SR-RRO subobjects"
whose format is shown below: whose format is shown below:
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
skipping to change at page 14, line 33 skipping to change at page 15, line 8
information about the bottommost label of the SR-TE LSP. information about the bottommost label of the SR-TE LSP.
5.4.1. RRO Processing 5.4.1. RRO Processing
Processing rules of SR-RRO subobject are identical to those of SR-ERO Processing rules of SR-RRO subobject are identical to those of SR-ERO
subobject. subobject.
If a PCEP speaker receives an SR-RRO subobject in which both SID and If a PCEP speaker receives an SR-RRO subobject in which both SID and
NAI are absent, it MUST consider the entire RRO object invalid and NAI are absent, it MUST consider the entire RRO object invalid and
send a PCErr message with Error-Type = 10 ("Reception of an invalid send a PCErr message with Error-Type = 10 ("Reception of an invalid
object") and Error-Value = TBD ("Both SID and NAI are absent in RRO object") and Error-Value = 7 ("Both SID and NAI are absent in RRO
subobject"). subobject").
If a PCE detects that all subobjects of RRO are not identical, and if If a PCE detects that all subobjects of RRO are not identical, and if
it does not handle such RRO, it MUST send a PCErr message with Error- it does not handle such RRO, it MUST send a PCErr message with Error-
Type = 10 ("Reception of an invalid object") and Error-Value = TBD Type = 10 ("Reception of an invalid object") and Error-Value = 10
("Non-identical RRO subobjects"). ("Non-identical RRO subobjects").
5.5. METRIC Object 5.5. METRIC Object
If a PCEP session is established with an MSD value of zero, then the If a PCEP session is established with an MSD value of zero, then the
PCC MAY specify the MSD for an individual path computation request PCC MAY specify the MSD for an individual path computation request
using the METRIC object defined in [RFC5440]. This document defines using the METRIC object defined in [RFC5440]. This document defines
a new type for the METRIC object to be used for this purpose as a new type for the METRIC object to be used for this purpose as
follows: follows:
o T = TBD (suggested value 11): Maximum SID Depth of the requested o T = 11: Maximum SID Depth of the requested path.
path.
The PCC sets the metric-value to the MSD for this path. The PCC MUST The PCC sets the metric-value to the MSD for this path. The PCC MUST
set the B (bound) bit to 1 in the METRIC object, which specifies that set the B (bound) bit to 1 in the METRIC object, which specifies that
the SID depth for the computed path MUST NOT exceed the metric-value. the SID depth for the computed path MUST NOT exceed the metric-value.
If a PCEP session is established with a non-zero MSD value, then the If a PCEP session is established with a non-zero MSD value, then the
PCC MUST NOT send an MSD METRIC object. If the PCE receives a path PCC MUST NOT send an MSD METRIC object. If the PCE receives a path
computation request with an MSD METRIC object on a session with a computation request with an MSD METRIC object on a session with a
non-zero MSD value then it MUST consider the request invalid and send non-zero MSD value then it MUST consider the request invalid and send
a PCErr with Error-Type = 10 ("Reception of an invalid object") and a PCErr with Error-Type = 10 ("Reception of an invalid object") and
Error-Value TBD ("Default MSD is specified for the PCEP session"). Error-Value 9 ("Default MSD is specified for the PCEP session").
6. Backward Compatibility 6. Backward Compatibility
A PCEP speaker that does not support the SR PCEP capability cannot A PCEP speaker that does not support the SR PCEP capability cannot
recognize the SR-ERO or SR-RRO subobjects. As such, it MUST send a recognize the SR-ERO or SR-RRO subobjects. As such, it MUST send a
PCEP error with Error-Type = 4 (Not supported object) and Error-Value PCEP error with Error-Type = 4 (Not supported object) and Error-Value
= 2 (Not supported object Type) as per [RFC5440]. = 2 (Not supported object Type) as per [RFC5440].
Some implementations, which are compliant with an earlier version of
this specification, do not send the PATH-SETUP-TYPE-CAPABILITY TLV in
their OPEN objects. Instead, to indicate that they support SR, these
implementations include the SR-CAPABILITY-TLV as a top-level TLV in
the OPEN object. Unfortunately, some of these implementations made
it into the field before this document was published in its final
form. Therefore, if a PCEP speaker receives an OPEN object in which
the SR-CAPABILITY-TLV appears as a top-level TLV, then it MUST
interpret this as though the sender had sent a PATH-SETUP-TYPE-
CAPABILITY TLV with a PST list of (0, 1) (that is, both RSVP-TE and
SR-TE PSTs are supported) and with the SR-CAPABILITY-TLV as a sub-
TLV. If a PCEP speaker receives an OPEN object in which both the SR-
CAPABILITY-TLV and PATH-SETUP-TYPE-CAPABILITY TLV appear as top-level
TLVs, then it MUST ignore the top-level SR-CAPABILITY-TLV and process
only the PATH-SETUP-TYPE-CAPABILITY TLV.
7. Management Considerations 7. Management Considerations
7.1. Policy 7.1. Policy
PCEP implementation: PCEP implementation:
o Can enable SR PCEP capability either by default or via explicit o Can enable SR PCEP capability either by default or via explicit
configuration. configuration.
o May generate PCEP error due to unsupported number of SR-ERO or SR- o May generate PCEP error due to unsupported number of SR-ERO or SR-
RRO subobjects either by default or via explicit configuration. RRO subobjects either by default or via explicit configuration.
7.2. The PCEP Data Model 7.2. The PCEP Data Model
A PCEP MIB module is defined in [RFC7420]needs be extended to cover A PCEP MIB module is defined in [RFC7420]n eeds be extended to cover
additional functionality provided by [RFC5440] and additional functionality provided by [RFC5440] and
[I-D.ietf-pce-pce-initiated-lsp]. Such extension will cover the new [I-D.ietf-pce-pce-initiated-lsp]. Such extension will cover the new
functionality specified in this document. functionality specified in this document.
8. Security Considerations 8. Security Considerations
The security considerations described in [RFC5440] and The security considerations described in [RFC5440] and
[I-D.ietf-pce-pce-initiated-lsp] are applicable to this [I-D.ietf-pce-pce-initiated-lsp] are applicable to this
specification. No additional security measure is required. specification. No additional security measure is required.
skipping to change at page 16, line 4 skipping to change at page 16, line 37
[I-D.ietf-pce-pce-initiated-lsp]. Such extension will cover the new [I-D.ietf-pce-pce-initiated-lsp]. Such extension will cover the new
functionality specified in this document. functionality specified in this document.
8. Security Considerations 8. Security Considerations
The security considerations described in [RFC5440] and The security considerations described in [RFC5440] and
[I-D.ietf-pce-pce-initiated-lsp] are applicable to this [I-D.ietf-pce-pce-initiated-lsp] are applicable to this
specification. No additional security measure is required. specification. No additional security measure is required.
9. IANA Considerations 9. IANA Considerations
9.1. PCEP Objects 9.1. PCEP Objects
This document defines a new sub-object type for the PCEP explicit This document defines a new sub-object type for the PCEP explicit
route object (ERO), and a new sub-object type for the PCEP record route object (ERO), and a new sub-object type for the PCEP record
route object (RRO). The code points for sub-object types of these route object (RRO). The code points for sub-object types of these
objects is maintained in the RSVP parameters registry, under the objects is maintained in the RSVP parameters registry, under the
EXPLICIT_ROUTE and ROUTE_RECORD objects. IANA is requested to EXPLICIT_ROUTE and ROUTE_RECORD objects. IANA is requested to
allocate code points in the RSVP Parameters registry for each of the confirm the early allocation of the following code points in the RSVP
new sub-object types defined in this document, as follows: Parameters registry for each of the new sub-object types defined in
this document.
Object Sub-Object Sub-Object Type Object Sub-Object Sub-Object Type
--------------------- -------------------------- ------------------ --------------------- -------------------------- ------------------
EXPLICIT_ROUTE SR-ERO (PCEP-specific) TBD (recommended 36) EXPLICIT_ROUTE SR-ERO (PCEP-specific) 36
ROUTE_RECORD SR-RRO (PCEP-specific) TBD (recommended 36) ROUTE_RECORD SR-RRO (PCEP-specific) 36
9.2. PCEP-Error Object 9.2. PCEP-Error Object
IANA is requested to allocate code-points in the PCEP-ERROR Object IANA is requested to confirm the early allocation of the code-points
Error Types and Values registry for the following new error-values: in the PCEP-ERROR Object Error Types and Values registry for the
following new error-values:
Error-Type Meaning Error-Type Meaning
---------- ------- ---------- -------
10 Reception of an invalid object. 10 Reception of an invalid object.
Error-value = TBD (recommended 2): Bad label value Error-value = 2: Bad label value
Error-value = TBD (recommended 3): Unsupported number Error-value = 3: Unsupported number
of Segment ERO of Segment ERO
subobjects subobjects
Error-value = TBD (recommended 4): Bad label format Error-value = 4: Bad label format
Error-value = TBD (recommended 5): Non-identical ERO Error-value = 5: Non-identical ERO
subobjects subobjects
Error-value = TBD (recommended 6): Both SID and NAI Error-value = 6: Both SID and NAI
are absent in ERO are absent in ERO
subobject subobject
Error-value = TBD (recommended 7): Both SID and NAI Error-value = 7: Both SID and NAI
are absent in RRO are absent in RRO
subobject subobject
Error-value = TBD (recommended 9): Default MSD is Error-value = 9: Default MSD is
specified for the specified for the
PCEP session PCEP session
Error-value = TBD (recommended 10): Non-identical RRO Error-value = 10: Non-identical RRO
subobjects subobjects
Error-value = TBD (recommended 11): Malformed object Error-value = TBD1: Missing PCE-SR-
CAPABILITY sub-TLV
Note to IANA: this draft originally had an early allocation for
Error-value=11 (Malformed object) in the above list. However, we
have since moved the definition of that code point to draft-ietf-pce-
lsp-setup-type and we included an instruction in that draft for you
to update the reference in the indicated registry. Please ensure
that this has happened when you process the present draft.
Note to IANA: the final Error-value (Missing PCE-SR-CAPABILITY sub-
TLV) in the above list was defined after the early allocation took
place, and so does not currently have a code point assigned. Please
assign a code point from the indicated registry and replace each
instance of "TBD1" in this document with the allocated code point.
9.3. PCEP TLV Type Indicators 9.3. PCEP TLV Type Indicators
IANA is requested to allocate a new code point in the PCEP TLV Type IANA is requested to confirm the early allocation of the following
Indicators registry, as follows: code point in the PCEP TLV Type Indicators registry.
Value Meaning Reference Value Meaning Reference
------------------------- ---------------------------- -------------- ------------------------- ---------------------------- --------------
TBD (recommended 26) SR-PCE-CAPABILITY This document 26 SR-PCE-CAPABILITY This document
9.4. New Path Setup Type 9.4. New Path Setup Type
[I-D.ietf-pce-lsp-setup-type] defines the PATH-SETUP-TYPE TLV and [I-D.ietf-pce-lsp-setup-type] requests that IANA creates a sub-
requests that IANA creates a registry to manage the value of the registry within the "Path Computation Element Protocol (PCEP)
PATH_SETUP_TYPE TLV's PST field. IANA is requested to allocate a new Numbers" registry called "PCEP Path Setup Types". IANA is requested
code point in the PCEP PATH_SETUP_TYPE TLV PST field registry, as to allocate a new code point within this registry, as follows:
follows:
Value Description Reference Value Description Reference
------------------------- ---------------------------- -------------- ------------------------- ---------------------------- --------------
1 Traffic engineering path is This document 1 Traffic engineering path is This document
setup using Segment Routing setup using Segment Routing.
technique.
9.5. New Metric Type 9.5. New Metric Type
IANA is requested to allocate a new code point in the PCEP METRIC IANA is requested to confirm the early allocation of the following
object T field registry, as follows: code point in the PCEP METRIC object T field registry:
Value Description Reference Value Description Reference
------------------------- ---------------------------- -------------- ------------------------- ---------------------------- --------------
TBD (recommended 11) Segment-ID (SID) Depth. This document 11 Segment-ID (SID) Depth. This document
10. Contributors 10. Contributors
The following people contributed to this document: The following people contributed to this document:
- Lakshmi Sharma - Lakshmi Sharma
- Jan Medved - Jan Medved
- Edward Crabbe - Edward Crabbe
- Robert Raszuk - Robert Raszuk
- Victor Lopez - Victor Lopez
11. Acknowledgements 11. Acknowledgements
We like to thank Ina Minei, George Swallow, Marek Zavodsky, Dhruv We thank Ina Minei, George Swallow, Marek Zavodsky, Dhruv Dhody, Ing-
Dhody, Ing-Wher Chen and Tomas Janciga for the valuable comments. Wher Chen and Tomas Janciga for the valuable comments.
12. References 12. References
12.1. Normative References 12.1. Normative References
[I-D.ietf-idr-bgp-ls-segment-routing-msd]
Tantsura, J., Chunduri, U., Mirsky, G., and S. Sivabalan,
"Signaling Maximum SID Depth using Border Gateway Protocol
Link-State", draft-ietf-idr-bgp-ls-segment-routing-msd-01
(work in progress), October 2017.
[I-D.ietf-isis-segment-routing-extensions] [I-D.ietf-isis-segment-routing-extensions]
Previdi, S., Filsfils, C., Bashandy, A., Gredler, H., Previdi, S., Filsfils, C., Bashandy, A., Gredler, H.,
Litkowski, S., Decraene, B., and j. jefftant@gmail.com, Litkowski, S., Decraene, B., and j. jefftant@gmail.com,
"IS-IS Extensions for Segment Routing", draft-ietf-isis- "IS-IS Extensions for Segment Routing", draft-ietf-isis-
segment-routing-extensions-11 (work in progress), March segment-routing-extensions-13 (work in progress), June
2017. 2017.
[I-D.ietf-isis-segment-routing-msd] [I-D.ietf-isis-segment-routing-msd]
Tantsura, J., Chunduri, U., Aldrin, S., and L. Ginsberg, Tantsura, J., Chunduri, U., Aldrin, S., and L. Ginsberg,
"Signaling MSD (Maximum SID Depth) using IS-IS", draft- "Signaling MSD (Maximum SID Depth) using IS-IS", draft-
ietf-isis-segment-routing-msd-03 (work in progress), March ietf-isis-segment-routing-msd-04 (work in progress), June
2017. 2017.
[I-D.ietf-ospf-segment-routing-extensions] [I-D.ietf-ospf-segment-routing-extensions]
Psenak, P., Previdi, S., Filsfils, C., Gredler, H., Psenak, P., Previdi, S., Filsfils, C., Gredler, H.,
Shakir, R., Henderickx, W., and J. Tantsura, "OSPF Shakir, R., Henderickx, W., and J. Tantsura, "OSPF
Extensions for Segment Routing", draft-ietf-ospf-segment- Extensions for Segment Routing", draft-ietf-ospf-segment-
routing-extensions-12 (work in progress), March 2017. routing-extensions-21 (work in progress), October 2017.
[I-D.ietf-ospf-segment-routing-msd] [I-D.ietf-ospf-segment-routing-msd]
Tantsura, J., Chunduri, U., Aldrin, S., and P. Psenak, Tantsura, J., Chunduri, U., Aldrin, S., and P. Psenak,
"Signaling MSD (Maximum SID Depth) using OSPF", draft- "Signaling MSD (Maximum SID Depth) using OSPF", draft-
ietf-ospf-segment-routing-msd-04 (work in progress), March ietf-ospf-segment-routing-msd-05 (work in progress), June
2017. 2017.
[I-D.ietf-pce-lsp-setup-type] [I-D.ietf-pce-lsp-setup-type]
Sivabalan, S., Medved, J., Minei, I., Crabbe, E., Varga, Sivabalan, S., Tantsura, J., Minei, I., Varga, R., and J.
R., Tantsura, J., and J. Hardwick, "Conveying path setup Hardwick, "Conveying path setup type in PCEP messages",
type in PCEP messages", draft-ietf-pce-lsp-setup-type-03 draft-ietf-pce-lsp-setup-type-05 (work in progress),
(work in progress), June 2015. October 2017.
[I-D.ietf-pce-pce-initiated-lsp] [I-D.ietf-pce-pce-initiated-lsp]
Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "PCEP Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "PCEP
Extensions for PCE-initiated LSP Setup in a Stateful PCE Extensions for PCE-initiated LSP Setup in a Stateful PCE
Model", draft-ietf-pce-pce-initiated-lsp-09 (work in Model", draft-ietf-pce-pce-initiated-lsp-11 (work in
progress), March 2017. progress), October 2017.
[I-D.ietf-pce-stateful-pce]
Crabbe, E., Minei, I., Medved, J., and R. Varga, "PCEP
Extensions for Stateful PCE", draft-ietf-pce-stateful-
pce-18 (work in progress), December 2016.
[I-D.ietf-spring-segment-routing] [I-D.ietf-spring-segment-routing]
Filsfils, C., Previdi, S., Decraene, B., Litkowski, S., Filsfils, C., Previdi, S., Decraene, B., Litkowski, S.,
and R. Shakir, "Segment Routing Architecture", draft-ietf- and R. Shakir, "Segment Routing Architecture", draft-ietf-
spring-segment-routing-11 (work in progress), February spring-segment-routing-12 (work in progress), June 2017.
2017.
[I-D.tantsura-idr-bgp-ls-segment-routing-msd]
Tantsura, J., Chunduri, U., Mirsky, G., and S. Sivabalan,
"Signaling Maximum SID Depth using Border Gateway Protocol
Link-State", draft-tantsura-idr-bgp-ls-segment-routing-
msd-02 (work in progress), January 2017.
[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-
<https://www.rfc-editor.org/info/rfc2119>. editor.org/info/rfc2119>.
[RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
Element (PCE) Communication Protocol (PCEP)", RFC 5440, Element (PCE) Communication Protocol (PCEP)", RFC 5440,
DOI 10.17487/RFC5440, March 2009, DOI 10.17487/RFC5440, March 2009, <https://www.rfc-
<https://www.rfc-editor.org/info/rfc5440>. editor.org/info/rfc5440>.
[RFC5462] Andersson, L. and R. Asati, "Multiprotocol Label Switching [RFC5462] Andersson, L. and R. Asati, "Multiprotocol Label Switching
(MPLS) Label Stack Entry: "EXP" Field Renamed to "Traffic (MPLS) Label Stack Entry: "EXP" Field Renamed to "Traffic
Class" Field", RFC 5462, DOI 10.17487/RFC5462, February Class" Field", RFC 5462, DOI 10.17487/RFC5462, February
2009, <https://www.rfc-editor.org/info/rfc5462>. 2009, <https://www.rfc-editor.org/info/rfc5462>.
[RFC7420] Koushik, A., Stephan, E., Zhao, Q., King, D., and J. [RFC7420] Koushik, A., Stephan, E., Zhao, Q., King, D., and J.
Hardwick, "Path Computation Element Communication Protocol Hardwick, "Path Computation Element Communication Protocol
(PCEP) Management Information Base (MIB) Module", (PCEP) Management Information Base (MIB) Module",
RFC 7420, DOI 10.17487/RFC7420, December 2014, RFC 7420, DOI 10.17487/RFC7420, December 2014,
<https://www.rfc-editor.org/info/rfc7420>. <https://www.rfc-editor.org/info/rfc7420>.
[RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path
Computation Element Communication Protocol (PCEP)
Extensions for Stateful PCE", RFC 8231,
DOI 10.17487/RFC8231, September 2017, <https://www.rfc-
editor.org/info/rfc8231>.
12.2. Informative References 12.2. Informative References
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
<https://www.rfc-editor.org/info/rfc3209>. <https://www.rfc-editor.org/info/rfc3209>.
[RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation Protocol- Switching (GMPLS) Signaling Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE) Extensions", RFC 3473, Traffic Engineering (RSVP-TE) Extensions", RFC 3473,
DOI 10.17487/RFC3473, January 2003, DOI 10.17487/RFC3473, January 2003, <https://www.rfc-
<https://www.rfc-editor.org/info/rfc3473>. editor.org/info/rfc3473>.
[RFC3477] Kompella, K. and Y. Rekhter, "Signalling Unnumbered Links [RFC3477] Kompella, K. and Y. Rekhter, "Signalling Unnumbered Links
in Resource ReSerVation Protocol - Traffic Engineering in Resource ReSerVation Protocol - Traffic Engineering
(RSVP-TE)", RFC 3477, DOI 10.17487/RFC3477, January 2003, (RSVP-TE)", RFC 3477, DOI 10.17487/RFC3477, January 2003,
<https://www.rfc-editor.org/info/rfc3477>. <https://www.rfc-editor.org/info/rfc3477>.
[RFC4657] Ash, J., Ed. and J. Le Roux, Ed., "Path Computation [RFC4657] Ash, J., Ed. and J. Le Roux, Ed., "Path Computation
Element (PCE) Communication Protocol Generic Element (PCE) Communication Protocol Generic
Requirements", RFC 4657, DOI 10.17487/RFC4657, September Requirements", RFC 4657, DOI 10.17487/RFC4657, September
2006, <https://www.rfc-editor.org/info/rfc4657>. 2006, <https://www.rfc-editor.org/info/rfc4657>.
skipping to change at page 21, line 10 skipping to change at page 22, line 10
Antwerp 2018, CA 95134 Antwerp 2018, CA 95134
BELGIUM BELGIUM
Email: wim.henderickx@alcatel-lucent.com Email: wim.henderickx@alcatel-lucent.com
Jon Hardwick Jon Hardwick
Metaswitch Networks Metaswitch Networks
100 Church Street 100 Church Street
Enfield, Middlesex Enfield, Middlesex
UK UK
Email: jon.hardwick@metaswitch.com Email: jonathan.hardwick@metaswitch.com
 End of changes. 90 change blocks. 
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