IDR R. Chen
Internet-Draft D. Zhao
Intended status: Standards Track ZTE Corporation
Expires: 16 October 2023 L. Gong
China mobile
Y. Zhu
China Telecom
14 April 2023
SR Policies Extensions for NRP in BGP-LS
draft-chen-idr-bgp-ls-sr-policy-nrp-02
Abstract
This document defines a new TLV which enable the headed to report the
configuration and the states of SR policies carrying NRP information
by using BGP-LS.
Status of This Memo
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This Internet-Draft will expire on 16 October 2023.
Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
3. Carrying NRP TLV in BGP-LS . . . . . . . . . . . . . . . . . 3
4. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. Normative References . . . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
Segment Routing Policy [RFC9256] is an ordered list of segments (i.e.
instructions) that represent a source-routed policy. Packet flows
are steered into a SR Policy on a node where it is instantiated
called a headend node. The packets steered into an SR Policy carry
an ordered list of segments associated with that SR Policy.
[I-D.ietf-teas-ietf-network-slices] provides the definition of IETF
network slice for use within the IETF and discusses the general
framework for requesting and operating IETF Network Slices, their
characteristics, and the necessary system components and
interfaces.It also introduces the concept Network Resource Partition
(NRP), which is a subset of the resources and associated policies in
the underlay network.
[I-D.ietf-teas-ns-ip-mpls]introduces the notion of a Slice-Flow
Aggregate which comprises of one or more IETF network slice traffic
streams. It also describes the Network Resource Partition (NRP) and
the NRP Policy that can be used to instantiate control and data plane
behaviors on select topological elements associated with the NRP that
supports a Slice-Flow Aggregate.
[I-D.ietf-idr-bgp-ls-sr-policy] describes a mechanism to distribute
SR policy information to external components using BGP-LS.
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[I-D.dong-idr-sr-policy-nrp] defines the extensions to BGP SR policy
to specify the NRP which the SR Policy candidate path is associated
with.
This document defines a new TLV which enable the headed to report the
configuration and the states of an SR policy carrying the NRP
information by using BPG-LS.
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].
3. Carrying NRP TLV in BGP-LS
In order to collect configuration and states of the NRP SR policy,
this document defines a new SR Policy state TLV which enable the
headend to report the state at the SR Policy CP level.
This TLV is carried in the optional non-transitive BGP Attribute
"LINK_STATE Attribute" defined in [RFC7752]associated with the SR
Policy CP NLRI type.
This TLV is optional and only one this TLV is advertised for a given
CP. If multiple TLVs are present, then the first one is considered
valid and the rest are ignored as describe in
[I-D.ietf-idr-bgp-ls-sr-policy].
The TLV has the following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Flags | RESERVED |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| NRP ID (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
Type: TBD1.
Length: 6 octets.
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Flags: 1 octet of flags. None are defined at this stage. Flags
SHOULD be set to zero on transmission and MUST be ignored on receipt.
RESERVED: 1 octet of reserved bits. SHOULD be set to zero on
transmission and MUST be ignored on receipt.
NRP: 4 octet global identifier of Network Resource Partition.
4. Acknowledgements
TBD.
5. IANA Considerations
IANA maintains a registry called "Border Gateway Protocol - Link
State (BGP-LS) Parameters" with a sub-registry called "BGP-LS NLRI
and Attribute TLVs". The following TLV codepoints are suggested (for
early allocation by IANA):
Codepoint Description Reference
----------------------------------------------------------
TBA NRP TLV This document
6. Security Considerations
TBD.
7. Normative References
[I-D.dong-idr-sr-policy-nrp]
Dong, J., Hu, Z., and R. Pang, "BGP SR Policy Extensions
for Network Resource Partition", Work in Progress,
Internet-Draft, draft-dong-idr-sr-policy-nrp-02, 30
January 2023, <https://datatracker.ietf.org/doc/html/
draft-dong-idr-sr-policy-nrp-02>.
[I-D.ietf-idr-bgp-ls-sr-policy]
Previdi, S., Talaulikar, K., Dong, J., Gredler, H., and J.
Tantsura, "Advertisement of Segment Routing Policies using
BGP Link-State", Work in Progress, Internet-Draft, draft-
ietf-idr-bgp-ls-sr-policy-00, 9 March 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-idr-bgp-
ls-sr-policy-00>.
[I-D.ietf-teas-ietf-network-slices]
Farrel, A., Drake, J., Rokui, R., Homma, S., Makhijani,
K., Contreras, L. M., and J. Tantsura, "A Framework for
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IETF Network Slices", Work in Progress, Internet-Draft,
draft-ietf-teas-ietf-network-slices-19, 21 January 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-teas-
ietf-network-slices-19>.
[I-D.ietf-teas-ns-ip-mpls]
Saad, T., Beeram, V. P., Dong, J., Wen, B., Ceccarelli,
D., Halpern, J. M., Peng, S., Chen, R., Liu, X.,
Contreras, L. M., Rokui, R., and L. Jalil, "Realizing
Network Slices in IP/MPLS Networks", Work in Progress,
Internet-Draft, draft-ietf-teas-ns-ip-mpls-02, 13 March
2023, <https://datatracker.ietf.org/doc/html/draft-ietf-
teas-ns-ip-mpls-02>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and
S. Ray, "North-Bound Distribution of Link-State and
Traffic Engineering (TE) Information Using BGP", RFC 7752,
DOI 10.17487/RFC7752, March 2016,
<https://www.rfc-editor.org/info/rfc7752>.
[RFC9256] Filsfils, C., Talaulikar, K., Ed., Voyer, D., Bogdanov,
A., and P. Mattes, "Segment Routing Policy Architecture",
RFC 9256, DOI 10.17487/RFC9256, July 2022,
<https://www.rfc-editor.org/info/rfc9256>.
Authors' Addresses
Ran Chen
ZTE Corporation
Nanjing
China
Email: chen.ran@zte.com.cn
Detao Zhao
ZTE Corporation
Nanjing
China
Email: zhao.detao@zte.com.cn
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Liyan Gong
China mobile
Beijing
China
Email: gongliyan@chinamobile.com
Yongqing Zhu
China Telecom
Guangzhou
China
Email: zhuyq8@chinatelecom.cn
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