Updates to PSC
draft-ietf-mpls-psc-updates-01
Network Working Group E. Osborne
Internet-Draft
Updates: RFC6378 (if approved) January 24, 2014
Intended status: Standards Track
Expires: July 28, 2014
Updates to PSC
draft-ietf-mpls-psc-updates-01
Abstract
This document contains four updates to the Protection State
Coordination (PSC) logic defined in RFC6378, "MPLS Transport Profile
(MPLS-TP) Linear Protection" . Two of the updates correct existing
behavior. The third clarifies a behavior which was not explained in
the RFC, and the fourth adds rules around handling capabilities
mismatches.
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].
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
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This Internet-Draft will expire on July 28, 2014.
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
Osborne Expires July 28, 2014 [Page 1]
Internet-Draft PSC-updates January 2014
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Incorrect local status after failure . . . . . . . . . . . . 3
3. Reversion deadlock due to a race condition . . . . . . . . . 3
4. Clarifying PSC's behavior in the face of multiple inputs . . 4
5. Handling a capabilities mismatch . . . . . . . . . . . . . . 6
5.1. Protection Type mismatch . . . . . . . . . . . . . . . . 6
5.2. R mismatch . . . . . . . . . . . . . . . . . . . . . . . 7
5.3. Unsupported modes . . . . . . . . . . . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Normative References . . . . . . . . . . . . . . . . . . 8
9.2. Informative References . . . . . . . . . . . . . . . . . 8
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
This document contains four updates to PSC [RFC6378]. Three of them
address issues #2, #7 and #8 as identified in the ITU's liaison
statement "Recommendation ITU-T G.8131/Y.1382 revision - Linear
protection switching for MPLS-TP networks" [LIAISON]. The fourth
clears up a behavior which was not well explained in RFC6378. These
updates are not changes to the protocol's packet format or to PSC's
design, but are corrections and clarifications to specific aspects of
the protocol's procedures.
This document assumes familiarity with RFC6378 and its terms,
conventions and acronyms. Any term used in this document but not
defined herein can be found in RFC6378. In particular, this document
shares the acronyms defined in RFC6378 section 2.1.
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2. Incorrect local status after failure
Issue #2 in the liaison identifies a case where a strict reading of
RFC6378 leaves a node reporting an inaccurate status:
A node can end up sending incorrect status - NR(0,1) - despite the
failure of the protection LSP (P-LSP). This is clearly not correct,
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