Signaling MSD (Maximum SID Depth) using OSPF
draft-ietf-ospf-segment-routing-msd-14
| The information below is for an old version of the document |
| Document |
Type |
|
Active Internet-Draft (lsr WG)
|
|
Last updated |
|
2018-05-31
(latest revision 2018-05-28)
|
|
Replaces |
|
draft-tantsura-ospf-segment-routing-msd
|
|
Stream |
|
IETF
|
|
Intended RFC status |
|
Proposed Standard
|
|
Formats |
|
plain text
pdf
html
bibtex
|
| Stream |
WG state
|
|
Submitted to IESG for Publication
|
|
Document shepherd |
|
Acee Lindem
|
|
Shepherd write-up |
|
Show
(last changed 2018-05-21)
|
| IESG |
IESG state |
|
Publication Requested
|
|
Consensus Boilerplate |
|
Yes
|
|
Telechat date |
|
|
|
Responsible AD |
|
Alvaro Retana
|
|
Send notices to |
|
Acee Lindem <acee@cisco.com>
|
OSPF Working Group J. Tantsura
Internet-Draft Nuage Networks
Intended status: Standards Track U. Chunduri
Expires: November 29, 2018 Huawei Technologies
S. Aldrin
Google, Inc
P. Psenak
Cisco Systems
May 28, 2018
Signaling MSD (Maximum SID Depth) using OSPF
draft-ietf-ospf-segment-routing-msd-14
Abstract
This document defines a way for an OSPF Router to advertise multiple
types of supported Maximum SID Depths (MSDs) at node and/or link
granularity. Such advertisements allow entities (e.g., centralized
controllers) to determine whether a particular SID stack can be
supported in a given network. This document defines only one type of
MSD, but defines an encoding that can support other MSD types. Here
the term OSPF means both OSPFv2 and OSPFv3.
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
working documents as Internet-Drafts. The list of current Internet-
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
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on November 29, 2018.
Copyright Notice
Copyright (c) 2018 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
Tantsura, et al. Expires November 29, 2018 [Page 1]
Internet-Draft May 2018
(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 Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Conventions used in this document . . . . . . . . . . . . 3
1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 3
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. Node MSD Advertisement . . . . . . . . . . . . . . . . . . . 4
3. Link MSD sub-TLV . . . . . . . . . . . . . . . . . . . . . . 5
4. Using Node and Link MSD Advertisements . . . . . . . . . . . 6
5. Base MPLS Imposition MSD . . . . . . . . . . . . . . . . . . 6
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 7
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 7
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
10.1. Normative References . . . . . . . . . . . . . . . . . . 8
10.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
When Segment Routing(SR) paths are computed by a centralized
controller, it is critical that the controller learns the Maximum SID
Depth(MSD) that can be imposed at each node/link on a given SR path
to insure that the SID stack depth of a computed path doesn't exceed
the number of SIDs the node is capable of imposing.
The PCEP SR extensions draft [I-D.ietf-pce-segment-routing] signals
MSD in SR PCE Capability TLV and METRIC Object. However, if PCEP is
not supported/configured on the head-end of an SR tunnel or a
Binding-SID anchor node and controller do not participate in IGP
routing, it has no way to learn the MSD of nodes and links. BGP-LS
[RFC7752] defines a way to expose topology and associated attributes
and capabilities of the nodes in that topology to a centralized
controller. MSD signaling by BGP-LS has been defined in
[I-D.ietf-idr-bgp-ls-segment-routing-msd]. Typically, BGP-LS is
configured on a small number of nodes that do not necessarily act as
Show full document text