| < draft-ietf-isis-segment-routing-msd-02.txt | draft-ietf-isis-segment-routing-msd-03.txt > | |||
|---|---|---|---|---|
| IS-IS Working Group J. Tantsura | IS-IS Working Group J. Tantsura | |||
| Internet-Draft Individual | Internet-Draft Individual | |||
| Intended status: Standards Track U. Chunduri | Intended status: Standards Track U. Chunduri | |||
| Expires: September 2, 2017 Huawei Technologies | Expires: September 29, 2017 Huawei Technologies | |||
| S. Aldrin | S. Aldrin | |||
| Google, Inc | Google, Inc | |||
| L. Ginsberg | L. Ginsberg | |||
| Cisco Systems | Cisco Systems | |||
| March 1, 2017 | March 28, 2017 | |||
| Signaling MSD (Maximum SID Depth) using IS-IS | Signaling MSD (Maximum SID Depth) using IS-IS | |||
| draft-ietf-isis-segment-routing-msd-02 | draft-ietf-isis-segment-routing-msd-03 | |||
| Abstract | Abstract | |||
| This document proposes a way to signal Maximum SID Depth (MSD) | This document proposes a way to signal Maximum SID Depth (MSD) | |||
| supported by a node at node and/or link granularity by an ISIS | supported by a node at node and/or link granularity by an IS-IS | |||
| Router. In a Segment Routing (SR) enabled network a centralized | Router. In a Segment Routing (SR) enabled network a centralized | |||
| controller that programs SR tunnels needs to know the MSD supported | controller that programs SR tunnels needs to know the MSD supported | |||
| by the head-end at node and/or link granularity to push the SID stack | by the head-end at node and/or link granularity to push the SID stack | |||
| of an appropriate depth. MSD is relevant to the head-end of a SR | of an appropriate depth. MSD is relevant to the head-end of a SR | |||
| tunnel or Binding-SID anchor node where Binding-SID expansions might | tunnel or Binding-SID anchor node where Binding-SID expansions might | |||
| result in creation of a new SID stack. | result in creation of a new SID stack. | |||
| 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 | |||
| skipping to change at page 1, line 41 ¶ | skipping to change at page 1, line 42 ¶ | |||
| 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 | |||
| working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
| Drafts is at http://datatracker.ietf.org/drafts/current/. | Drafts is at http://datatracker.ietf.org/drafts/current/. | |||
| Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
| and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
| 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 September 2, 2017. | This Internet-Draft will expire on September 29, 2017. | |||
| 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. | |||
| This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
| Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
| (http://trustee.ietf.org/license-info) in effect on the date of | (http://trustee.ietf.org/license-info) in effect on the date of | |||
| publication of this document. Please review these documents | publication of this document. Please review these documents | |||
| skipping to change at page 3, line 15 ¶ | skipping to change at page 3, line 15 ¶ | |||
| necessarily act as head-ends. In order, for BGP-LS to signal MSD for | necessarily act as head-ends. In order, for BGP-LS to signal MSD for | |||
| the all nodes and links in the network MSD is relevant, MSD | the all nodes and links in the network MSD is relevant, MSD | |||
| capabilites SHOULD be distributed to every IS-IS router in the | capabilites SHOULD be distributed to every IS-IS router in the | |||
| network. | network. | |||
| [I-D.ietf-isis-mpls-elc] defines Readable Label Depth Capability | [I-D.ietf-isis-mpls-elc] defines Readable Label Depth Capability | |||
| (RLDC) that is used by a head-end to insert Entropy Label (EL) at | (RLDC) that is used by a head-end to insert Entropy Label (EL) at | |||
| appropriate depth, so it could be read by transit nodes. MSD in | appropriate depth, so it could be read by transit nodes. MSD in | |||
| contrary signals ability to push SID's stack of a particular depth. | contrary signals ability to push SID's stack of a particular depth. | |||
| MSD of type 1 (IANA Registry) is used to signal the number of SIDs a | MSD of type 1 (IANA Registry), called Base MSD, is used to signal the | |||
| node is capable of imposing, to be used by a path computation | total number of SIDs a node is capable of imposing, to be used by a | |||
| element/controller and is only relevant to the part of the stack | path computation element/controller. In case, there are additional | |||
| created as the result of the computation. In case, there are | labels (e.g. service) that are to be pushed to the stack - this would | |||
| additional labels (e.g. service) that are to be pushed to the stack - | be signaled with an another MSD type (TBD), MSD SHOULD be adjusted to | |||
| MSD SHOULD be adjusted to reflect that. In the future, new MSD types | reflect that. In the future, new MSD types could be defined to | |||
| could be defined to signal additional capabilities: entropy labels, | signal additional capabilities: entropy labels, labels that can be | |||
| labels that can be pushed thru recirculation, etc. | pushed thru recirculation, or another dataplane e.g IPv6. | |||
| 1.1. Conventions used in this document | 1.1. Conventions used in this document | |||
| 1.1.1. Terminology | 1.1.1. Terminology | |||
| BGP-LS: Distribution of Link-State and TE Information using Border | BGP-LS: Distribution of Link-State and TE Information using Border | |||
| Gateway Protocol | Gateway Protocol | |||
| IS-IS: Intermediate System to Intermediate System | IS-IS: Intermediate System to Intermediate System | |||
| skipping to change at page 6, line 20 ¶ | skipping to change at page 6, line 20 ¶ | |||
| This document requests the creation of a new IANA managed registry to | This document requests the creation of a new IANA managed registry to | |||
| identify MSD types as proposed in Section 3, Section 4. The | identify MSD types as proposed in Section 3, Section 4. The | |||
| registration procedure is "Expert Review" as defined in [RFC5226]. | registration procedure is "Expert Review" as defined in [RFC5226]. | |||
| Suggested registry name is "MSD Sub-types". Types are an unsigned 8 | Suggested registry name is "MSD Sub-types". Types are an unsigned 8 | |||
| bit number. The following values are defined by this document | bit number. The following values are defined by this document | |||
| Value Name Reference | Value Name Reference | |||
| ----- --------------------- ------------- | ----- --------------------- ------------- | |||
| 0 Reserved This document | 0 Reserved This document | |||
| 1 MSD This document | 1 Base MSD This document | |||
| 2-250 Unassigned This document | 2-250 Unassigned This document | |||
| 251-254 Experimental This document | 251-254 Experimental This document | |||
| 255 Reserved This document | 255 Reserved This document | |||
| Figure 4: MSD Sub-type Codepoints Registry | Figure 4: MSD Sub-type Codepoints Registry | |||
| 7. Security Considerations | 7. Security Considerations | |||
| This document describes a mechanism to signal Segment Routing MSD | This document describes a mechanism to signal Segment Routing MSD | |||
| supported at node and/or link granularity through IS-IS LSPs and does | supported at node and/or link granularity through IS-IS LSPs and does | |||
| skipping to change at page 7, line 39 ¶ | skipping to change at page 7, line 39 ¶ | |||
| Sivabalan, S., Medved, J., Filsfils, C., Crabbe, E., | Sivabalan, S., Medved, J., Filsfils, C., Crabbe, E., | |||
| Raszuk, R., Lopez, V., Tantsura, J., Henderickx, W., and | Raszuk, R., Lopez, V., Tantsura, J., Henderickx, W., and | |||
| J. Hardwick, "PCEP Extensions for Segment Routing", draft- | J. Hardwick, "PCEP Extensions for Segment Routing", draft- | |||
| ietf-pce-segment-routing-08 (work in progress), October | ietf-pce-segment-routing-08 (work in progress), October | |||
| 2016. | 2016. | |||
| [I-D.tantsura-idr-bgp-ls-segment-routing-msd] | [I-D.tantsura-idr-bgp-ls-segment-routing-msd] | |||
| Tantsura, J., Chunduri, U., Mirsky, G., and S. Sivabalan, | Tantsura, J., Chunduri, U., Mirsky, G., and S. Sivabalan, | |||
| "Signaling Maximum SID Depth using Border Gateway Protocol | "Signaling Maximum SID Depth using Border Gateway Protocol | |||
| Link-State", draft-tantsura-idr-bgp-ls-segment-routing- | Link-State", draft-tantsura-idr-bgp-ls-segment-routing- | |||
| msd-02 (work in progress), January 2017. | msd-03 (work in progress), March 2017. | |||
| [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, <http://www.rfc-editor.org/info/rfc1195>. | December 1990, <http://www.rfc-editor.org/info/rfc1195>. | |||
| [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi | [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi | |||
| Topology (MT) Routing in Intermediate System to | Topology (MT) Routing in Intermediate System to | |||
| Intermediate Systems (IS-ISs)", RFC 5120, | Intermediate Systems (IS-ISs)", RFC 5120, | |||
| DOI 10.17487/RFC5120, February 2008, | DOI 10.17487/RFC5120, February 2008, | |||
| <http://www.rfc-editor.org/info/rfc5120>. | <http://www.rfc-editor.org/info/rfc5120>. | |||
| End of changes. 9 change blocks. | ||||
| 15 lines changed or deleted | 16 lines changed or added | |||
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