Updates to SID Verification for SR-MPLS in RFC 8664
draft-chen-pce-sr-mpls-sid-verification-02
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Active".
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|---|---|---|---|
| Authors | Ran Chen , Samuel Sidor , Chun Zhu , Alex Tokar , Mike Koldychev | ||
| Last updated | 2021-07-12 (Latest revision 2021-02-22) | ||
| RFC stream | (None) | ||
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draft-chen-pce-sr-mpls-sid-verification-02
Networking Working Group Ran. Chen
Internet-Draft ZTE Corporation
Intended status: Standards Track Samuel. Sidor
Expires: January 13, 2022 Cisco Systems, Inc.
Zhu. Chun
ZTE Corporation
Alex. Tokar
Mike. Koldychev
Cisco Systems, Inc.
July 12, 2021
Updates to SID Verification for SR-MPLS in RFC 8664
draft-chen-pce-sr-mpls-sid-verification-02
Abstract
This document updates [RFC8664] to clarify usage of "SID
verification" bit signalled in Path Computation Element Protocol
(PCEP), and this document proposes to define a new flag for
indicating the headend is explicitly requested to verify SID(s) by
the PCE.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 13, 2022.
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
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publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions used in this document . . . . . . . . . . . . . . 2
3. SID verification flag(V-Flag) . . . . . . . . . . . . . . . . 3
3.1. Extended V-Flag in SR-ERO Subobject . . . . . . . . . . . 3
3.2. Extended V-Flag in SR-RRO Subobject . . . . . . . . . . . 3
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
4.1. SR-ERO Subobject . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
7. Normative references . . . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4
1. Introduction
[I-D.ietf-spring-segment-routing-policy] describes the "SID
verification" bit usage. SID verification is performed when the
headend is explicitly requested to verify SID(s) by the controller
via the signaling protocol used. Implementations MAY provide a local
configuration option to enable verification on a global or per policy
or per candidate path basis.
[RFC8664] specifies extensions to the Path Computation Element
Communication Protocol (PCEP) that allow a stateful PCE to compute
and initiate Traffic-Engineering (TE) paths, as well as a Path
Computation Client (PCC) to request a path subject to certain
constraints and optimization criteria in SR networks.
This document updates [RFC8664] to clarify usage of "SID
verification" bit signalled in Path Computation Element Protocol
(PCEP), and this document proposes to define a new flag for
indicating the headend is explicitly requested to verify SID(s) by
the PCE.
2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC2119.
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3. SID verification flag(V-Flag)
3.1. Extended V-Flag in SR-ERO Subobject
Section 4.3.1 in Path Computation Element Communication Protocol
(PCEP) Extensions for Segment Routing [RFC8664] describes a new ERO
subobject referred to as the "SR-ERO subobject" to carry a SID and/or
NAI information. A new flag is proposed in this doucument in the SR-
ERO Subobject for indicating the pcc is explicitly requested to
verify SID(s) by the PCE.
The format of the SR-ERO subobject as defined in [RFC8664] is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Type=TBD | Length | NT | Flags |V|F|S|C|M|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// NAI (variable, optional) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1 SR-ERO Subobject Format of extended V-Flag
V: When the V-Flag is set then PCC MUST consider the "SID
verification" as described in Section 5.1 in
[I-D.ietf-spring-segment-routing-policy].
The other fields in the SR-ERO subobject is the same as that of the
SR-ERO subobject as defined in [RFC8664].
3.2. Extended V-Flag in SR-RRO Subobject
The format of the SR-RRO subobject is the same as that of the SR-ERO
subobject, but without the L-Flag, per [RFC8664].
The V flag has no meaning in the SR-RRO and is ignored on receipt at
the PCE.
4. IANA Considerations
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4.1. SR-ERO Subobject
This document defines a new bit value in the sub-registry "SR-ERO
Flag Field" in the "Path Computation Element Protocol (PCEP) Numbers"
registry.
Bit Name Reference
7 SID verification(V) This document
5. Security Considerations
TBD.
6. Acknowledgements
The authors thank Dhruv Dhody ,and JohnScudder for their suggestions
and comments.
7. Normative references
[I-D.ietf-spring-segment-routing-policy]
Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and
P. Mattes, "Segment Routing Policy Architecture", draft-
ietf-spring-segment-routing-policy-11 (work in progress),
April 2021.
[RFC8664] Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W.,
and J. Hardwick, "Path Computation Element Communication
Protocol (PCEP) Extensions for Segment Routing", RFC 8664,
DOI 10.17487/RFC8664, December 2019,
<https://www.rfc-editor.org/info/rfc8664>.
Authors' Addresses
Ran Chen
ZTE Corporation
Email: chen.ran@zte.com.cn
Samuel Sidor
Cisco Systems, Inc.
Email: ssidor@cisco.com
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Chun Zhu
ZTE Corporation
Email: zhu.chun1@zte.com.cn
Alex Tokar
Cisco Systems, Inc.
Email: atokar@cisco.com
Mike Koldychev
Cisco Systems, Inc.
Email: mkoldych@cisco.com
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