Update of the Pseudowire Control-Word Negotiation Mechanism
RFC 6723
Document | Type |
RFC - Proposed Standard
(September 2012; No errata)
Obsoleted by RFC 8077
|
|
---|---|---|---|
Last updated | 2015-10-14 | ||
Replaces | draft-jin-pwe3-cbit-negotiation | ||
Stream | IETF | ||
Formats | plain text pdf html bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Andrew Malis | ||
IESG | IESG state | RFC 6723 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Stewart Bryant | ||
IESG note | Andrew Malis (amalis@gmail.com) is the document shepherd. | ||
Send notices to | (None) |
Internet Engineering Task Force (IETF) L. Jin, Ed. Request for Comments: 6723 ZTE Updates: 4447, 6073 R. Key, Ed. Category: Standards Track Huawei ISSN: 2070-1721 S. Delord Alcatel-Lucent T. Nadeau Juniper S. Boutros Cisco Systems, Inc. September 2012 Update of the Pseudowire Control-Word Negotiation Mechanism Abstract The control-word negotiation mechanism specified in RFC 4447 has a problem when a PE (Provider Edge) changes the preference for the use of the control word from NOT PREFERRED to PREFERRED. This document updates RFC 4447 and RFC 6073 by adding the Label Request message to resolve this control-word negotiation issue for single-segment and multi-segment pseudowires. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc6723. Jin, et al. Standards Track [Page 1] RFC 6723 Update of PW C-Bit Negotiation September 2012 Copyright Notice Copyright (c) 2012 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 (http://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 2. Conventions Used in This Document . . . . . . . . . . . . . . . 3 3. Problem Statement . . . . . . . . . . . . . . . . . . . . . . . 3 4. Control-Word Renegotiation by Label Request Message . . . . . . 4 4.1. Control-Word Renegotiation for Multi-Segment PW . . . . . . 5 4.2. Control-Word Renegotiation Use Case . . . . . . . . . . . . 5 5. Backward Compatibility . . . . . . . . . . . . . . . . . . . . 6 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 7 9. Normative References . . . . . . . . . . . . . . . . . . . . . 7 Appendix A. Updated Diagram of C-Bit Handling Procedures . . . . . 8 1. Introduction The control-word negotiation mechanism specified in [RFC4447], Section 6.2, encounters a problem when a PE changes the preference for the use of the control word from NOT PREFERRED to PREFERRED. [RFC4447] specifies that if both endpoints prefer the use of the control word, then the pseudowire control word should be used. However, in the case where a PE changes its preference from NOT PREFERRED to PREFERRED and both ends of the PW (pseudowire) PE have the use of control word set as PREFERRED, an incorrect negotiated result of the control word as "not used" occurs. This document updates the control-word negotiation mechanism in [RFC4447] by adding a Label Request message to resolve this negotiation issue for single- segment PW. Multi-segment PW in [RFC6073] inherits the control-word negotiation mechanism in [RFC4447], and this document updates [RFC6073] by adding the processing of Label Request message on the Jin, et al. Standards Track [Page 2] RFC 6723 Update of PW C-Bit Negotiation September 2012 S-PE (Switching Provider Edge). When the PE changes the preference for the use of control word from PREFERRED to NOT PREFERRED, it should follow [RFC4447], and there is no problem. 2. Conventions Used in This Document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",Show full document text