| Internet-Draft | SID Verification for SR-MPLS Updates | July 2022 |
| Chen, et al. | Expires 9 January 2023 | [Page] |
- Workgroup:
- IDR
- Internet-Draft:
- draft-chen-pce-sr-mpls-sid-verification-04
- Published:
- Intended Status:
- Standards Track
- Expires:
Updates to SID Verification for SR-MPLS in RFC 8664
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
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This Internet-Draft will expire on 9 January 2023.¶
Copyright Notice
Copyright (c) 2022 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 publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶
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. Requirements Language
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 RFC 2119 [RFC2119].¶
cloud transport network: It is usually a national or province backbone network to achieve interconnection between multiple regional clouds/core clouds deployed in the country/province.¶
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) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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. Acknowledgements
TBD.¶
5. IANA Considerations
5.1. 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
TBA SID verification(V) This document
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", Work in Progress, Internet-Draft, draft-ietf-spring-segment-routing-policy-22, , <https://datatracker.ietf.org/doc/html/draft-ietf-spring-segment-routing-policy-22>.
- [RFC2119]
- Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
- [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, , <https://www.rfc-editor.org/info/rfc8664>.