< draft-filsfils-spring-sr-policy-considerations-08.txt   draft-filsfils-spring-sr-policy-considerations-09.txt >
SPRING Working Group C. Filsfils SPRING Working Group C. Filsfils
Internet-Draft K. Talaulikar, Ed. Internet-Draft Cisco Systems, Inc.
Intended status: Informational Cisco Systems, Inc. Intended status: Informational K. Talaulikar, Ed.
Expires: April 25, 2022 P. Krol Expires: October 26, 2022 Arrcus Inc
P. Krol
Google, Inc. Google, Inc.
M. Horneffer M. Horneffer
Deutsche Telekom Deutsche Telekom
P. Mattes P. Mattes
Microsoft Microsoft
October 22, 2021 April 24, 2022
SR Policy Implementation and Deployment Considerations SR Policy Implementation and Deployment Considerations
draft-filsfils-spring-sr-policy-considerations-08 draft-filsfils-spring-sr-policy-considerations-09
Abstract Abstract
Segment Routing (SR) allows a headend node to steer a packet flow Segment Routing (SR) allows a headend node to steer a packet flow
along any path. Intermediate per-flow states are eliminated thanks along any path. Intermediate per-flow states are eliminated thanks
to source routing. SR Policy framework enables the instantiation and to source routing. SR Policy framework enables the instantiation and
the management of necessary state on the headend node for flows along the management of necessary state on the headend node for flows along
a source routed paths using an ordered list of segments associated a source routed paths using an ordered list of segments associated
with their specific SR Policies. This document describes some of the with their specific SR Policies. This document describes some of the
implementation and deployment aspects that are useful for implementation and deployment aspects that are useful for
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Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. SR Policy Headend Architecture . . . . . . . . . . . . . . . 3 2. SR Policy Headend Architecture . . . . . . . . . . . . . . . 3
3. Dynamic Path Computation . . . . . . . . . . . . . . . . . . 4 3. Dynamic Path Computation . . . . . . . . . . . . . . . . . . 5
3.1. Optimization Objective . . . . . . . . . . . . . . . . . 4 3.1. Optimization Objective . . . . . . . . . . . . . . . . . 5
3.2. Constraints . . . . . . . . . . . . . . . . . . . . . . . 5 3.2. Constraints . . . . . . . . . . . . . . . . . . . . . . . 6
3.3. SR Native Algorithm . . . . . . . . . . . . . . . . . . . 6 3.3. SR Native Algorithm . . . . . . . . . . . . . . . . . . . 6
3.4. Path to SID . . . . . . . . . . . . . . . . . . . . . . . 7 3.4. Path to SID . . . . . . . . . . . . . . . . . . . . . . . 7
4. Candidate Path Selection . . . . . . . . . . . . . . . . . . 7 4. Candidate Path Selection . . . . . . . . . . . . . . . . . . 8
5. Distributed and/or Centralized Control Plane . . . . . . . . 11 5. Distributed and/or Centralized Control Plane . . . . . . . . 12
5.1. Distributed Control Plane within a single Link-State IGP 5.1. Distributed Control Plane within a single Link-State IGP
area . . . . . . . . . . . . . . . . . . . . . . . . . . 11 area . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2. Distributed Control Plane across several Link-State IGP 5.2. Distributed Control Plane across several Link-State IGP
areas . . . . . . . . . . . . . . . . . . . . . . . . . . 11 areas . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.3. Centralized Control Plane . . . . . . . . . . . . . . . . 12 5.3. Centralized Control Plane . . . . . . . . . . . . . . . . 12
5.4. Distributed and Centralized Control Plane . . . . . . . . 12 5.4. Distributed and Centralized Control Plane . . . . . . . . 13
6. Binding SID Aspects . . . . . . . . . . . . . . . . . . . . . 13 6. Binding SID Aspects . . . . . . . . . . . . . . . . . . . . . 13
6.1. Benefits of Binding SID . . . . . . . . . . . . . . . . . 13 6.1. Benefits of Binding SID . . . . . . . . . . . . . . . . . 14
6.2. Centralized Discovery of available BSID . . . . . . . . . 14 6.2. Centralized Discovery of available BSID . . . . . . . . . 15
7. Flex-Algorithm Based SR Policies . . . . . . . . . . . . . . 16 7. Flex-Algorithm Based SR Policies . . . . . . . . . . . . . . 16
8. Layer 2 and Optical Transport . . . . . . . . . . . . . . . . 17 8. Layer 2 and Optical Transport . . . . . . . . . . . . . . . . 17
9. Security Considerations . . . . . . . . . . . . . . . . . . . 18 9. Security Considerations . . . . . . . . . . . . . . . . . . . 18
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
11. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 18 11. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 19
12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 18 12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 19
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 20
13.1. Normative References . . . . . . . . . . . . . . . . . . 20 13.1. Normative References . . . . . . . . . . . . . . . . . . 20
13.2. Informative References . . . . . . . . . . . . . . . . . 20 13.2. Informative References . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction 1. Introduction
Segment Routing (SR) allows a headend node to steer a packet flow Segment Routing (SR) allows a headend node to steer a packet flow
along any path. Intermediate per-flow states are eliminated with along any path. Intermediate per-flow states are eliminated with
source routing [RFC8402]. source routing [RFC8402].
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Verizon Verizon
Email: luay.jalil@verizon.com Email: luay.jalil@verizon.com
13. References 13. References
13.1. Normative References 13.1. Normative References
[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-13 (work in progress), ietf-spring-segment-routing-policy-22 (work in progress),
May 2021. March 2022.
[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
July 2018, <https://www.rfc-editor.org/info/rfc8402>. July 2018, <https://www.rfc-editor.org/info/rfc8402>.
13.2. Informative References 13.2. Informative References
[I-D.anand-spring-poi-sr] [I-D.anand-spring-poi-sr]
Anand, M., Bardhan, S., Subrahmaniam, R., Tantsura, J., Anand, M., Bardhan, S., Subrahmaniam, R., Tantsura, J.,
Mukhopadhyaya, U., and C. Filsfils, "Packet-Optical Mukhopadhyaya, U., and C. Filsfils, "Packet-Optical
Integration in Segment Routing", draft-anand-spring-poi- Integration in Segment Routing", draft-anand-spring-poi-
sr-08 (work in progress), July 2019. sr-08 (work in progress), July 2019.
[I-D.ietf-idr-segment-routing-te-policy] [I-D.ietf-idr-segment-routing-te-policy]
Previdi, S., Filsfils, C., Talaulikar, K., Mattes, P., Previdi, S., Filsfils, C., Talaulikar, K., Mattes, P.,
Rosen, E., Jain, D., and S. Lin, "Advertising Segment Jain, D., and S. Lin, "Advertising Segment Routing
Routing Policies in BGP", draft-ietf-idr-segment-routing- Policies in BGP", draft-ietf-idr-segment-routing-te-
te-policy-13 (work in progress), June 2021. policy-17 (work in progress), April 2022.
[I-D.ietf-idr-te-lsp-distribution] [I-D.ietf-idr-te-lsp-distribution]
Previdi, S., Talaulikar, K., Dong, J., Chen, M., Gredler, Previdi, S., Talaulikar, K., Dong, J., Chen, M., Gredler,
H., and J. Tantsura, "Distribution of Traffic Engineering H., and J. Tantsura, "Distribution of Traffic Engineering
(TE) Policies and State using BGP-LS", draft-ietf-idr-te- (TE) Policies and State using BGP-LS", draft-ietf-idr-te-
lsp-distribution-15 (work in progress), May 2021. lsp-distribution-16 (work in progress), October 2021.
[I-D.ietf-lsr-flex-algo] [I-D.ietf-lsr-flex-algo]
Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and
A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex- A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex-
algo-17 (work in progress), July 2021. algo-19 (work in progress), April 2022.
[I-D.ietf-pce-binding-label-sid] [I-D.ietf-pce-binding-label-sid]
Sivabalan, S., Filsfils, C., Tantsura, J., Previdi, S., Sivabalan, S., Filsfils, C., Tantsura, J., Previdi, S.,
and C. L. (editor), "Carrying Binding Label/Segment and C. L. (editor), "Carrying Binding Label/Segment
Identifier in PCE-based Networks.", draft-ietf-pce- Identifier (SID) in PCE-based Networks.", draft-ietf-pce-
binding-label-sid-11 (work in progress), October 2021. binding-label-sid-15 (work in progress), March 2022.
[RFC1195] Callon, R., "Use of OSI IS-IS for routing in TCP/IP and [RFC1195] Callon, R., "Use of OSI IS-IS for routing in TCP/IP and
dual environments", RFC 1195, DOI 10.17487/RFC1195, dual environments", RFC 1195, DOI 10.17487/RFC1195,
December 1990, <https://www.rfc-editor.org/info/rfc1195>. December 1990, <https://www.rfc-editor.org/info/rfc1195>.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328,
DOI 10.17487/RFC2328, April 1998, DOI 10.17487/RFC2328, April 1998,
<https://www.rfc-editor.org/info/rfc2328>. <https://www.rfc-editor.org/info/rfc2328>.
[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
skipping to change at page 22, line 30 skipping to change at page 23, line 4
DOI 10.17487/RFC9085, August 2021, DOI 10.17487/RFC9085, August 2021,
<https://www.rfc-editor.org/info/rfc9085>. <https://www.rfc-editor.org/info/rfc9085>.
[RFC9086] Previdi, S., Talaulikar, K., Ed., Filsfils, C., Patel, K., [RFC9086] Previdi, S., Talaulikar, K., Ed., Filsfils, C., Patel, K.,
Ray, S., and J. Dong, "Border Gateway Protocol - Link Ray, S., and J. Dong, "Border Gateway Protocol - Link
State (BGP-LS) Extensions for Segment Routing BGP Egress State (BGP-LS) Extensions for Segment Routing BGP Egress
Peer Engineering", RFC 9086, DOI 10.17487/RFC9086, August Peer Engineering", RFC 9086, DOI 10.17487/RFC9086, August
2021, <https://www.rfc-editor.org/info/rfc9086>. 2021, <https://www.rfc-editor.org/info/rfc9086>.
Authors' Addresses Authors' Addresses
Clarence Filsfils Clarence Filsfils
Cisco Systems, Inc. Cisco Systems, Inc.
Pegasus Parc Pegasus Parc
De kleetlaan 6a, DIEGEM BRABANT 1831 De kleetlaan 6a, DIEGEM BRABANT 1831
BELGIUM BELGIUM
Email: cfilsfil@cisco.com Email: cfilsfil@cisco.com
Ketan Talaulikar (editor) Ketan Talaulikar (editor)
Cisco Systems, Inc. Arrcus Inc
Email: ketant.ietf@gmail.com Email: ketant.ietf@gmail.com
Przemyslaw Krol Przemyslaw Krol
Google, Inc. Google, Inc.
Email: pkrol@google.com Email: pkrol@google.com
Martin Horneffer Martin Horneffer
Deutsche Telekom Deutsche Telekom
Email: martin.horneffer@telekom.de Email: martin.horneffer@telekom.de
Paul Mattes Paul Mattes
Microsoft Microsoft
One Microsoft Way One Microsoft Way
Redmond, WA 98052-6399 Redmond, WA 98052-6399
USA USA
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