MPLS Working Group Dave Allan, Ed. Internet Draft Ericsson Intended status: Standards Track
Expires: January 2011 George Swallow Ed. Cisco Systems, Inc
John Drake Ed. Juniper
July 12, 2010 Proactive Connection Verification, Continuity Check and Remote
Defect indication for MPLS Transport Profile
draft-ietf-mpls-tp-cc-cv-rdi-01
Abstract
Continuity Check (CC), Proactive Connectivity Verification (CV) and
姜汁可乐的做法Remote Defect Indication (RDI) functionalities required for are MPLS- TP OAM.
Continuity Check monitors the integrity of the continuity of the path for any loss of continuity defect. C
onnectivity verification monitors the integrity of the routing of the path between sink and source for any connectivity issues. RDI enables an End Point to report, to its
associated End Point, a fault or defect condition that it detects on a PW, LSP or Section.
This document specifies methods for proactive CV, CC, and RDI for
MPLS-TP Label Switched Path (LSP), PWs and Sections using
Bidirectional Forwarding Detection (BFD).
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 RFC2119 [1].
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance
with the provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet
Engineering Task Force (IETF), its areas, and its working
Allan et al., Expires January 12, 2011 [Page 1]
Internet-Draft draft-ietf-mpls-tp-cc-cv-rdi-01 July 2010 groups. Note that other groups may also distribute working
documents as Internet-Drafts.
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 u Internet-
Drafts as reference material or to cite them other than as "work
in progress".
The list of current Internet-Drafts can be accesd at
/
The list of Internet-Draft Shadow Directories can be accesd at
/shadow.html.
This Internet-Draft will expire on November 28, 2010.
Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights rerved.
This document is subject to BCP 78 and the IETF Trust’s Legal
Provisions Relating to IETF Documents
(/licen-info) in effect on the date of
publication of this document. Plea review the documents
carefully, as they describe your rights and restrictions with
手工兔子制作respect to this document. Code Components extracted from this
document must include Simplified BSD Licen text as described
in Section 4.e of the Trust Legal Provisions and are provided
without warranty as described in the Simplified BSD Licen.
Table of Contents
1. Introduction (3)
1.1. Authors (4)
2. Conventions ud in this document (4)
2.1. Terminology (4)450字的作文
2.2. Issues for discussion (4)
3. MPLS CC, proactive CV and RDI Mechanism using BFD (5)
3.1. ACH code points for CC and proactive CV (5)
3.2. MPLS BFD CC Message format (6)
3.3. MPLS BFD proactive CV Message format (6)
3.4. BFD Session in MPLS-TP terminology (7)
3.5. BFD Profile for MPLS-TP (7)
3.5.1. Session initiation (8)
3.5.2. Defect entry criteria (8)
Allan et al., Expires January 12, 2011 [Page 2]
Internet-Draft draft-ietf-mpls-tp-cc-cv-rdi-01 July 2010 3.5.3. Defect entry conquent action (10)
3.5.4. Defect exit criteria (10)
3.5.5. State machines (10)
3.5.6. Configuration of MPLS-TP BFD ssions (13)
3.5.7. Discriminator values (13)
4. Acknowledgments (13)
5. IANA Considerations (14)
6. Security Considerations (14)
7. References (14)
7.1. Normative References (14)
7.2. Informative References (15)
1. Introduction
yys桌面版
In traditional transport networks, circuits are provisioned on two or more switches. Service Providers (SP) need OAM tools to detect mis-
connectivity and loss of continuity of transport circuits. Both PWs
and MPLS-TP LSPs [7] emulating traditional transport circuits need to provide the same CC and proactive CV capabilities as required in
draft-ietf-mpls-tp-oam-requirements[3]. This document describes the
u of BFD for CC, proactive CV, and RDI of a PW, LSP or PST between two Maintenance Entity Group End Points (MEPs).
As described in [9], Continuity Check (CC) and Proactive Connectivity Verification (CV) functions are ud to detect loss of continuity
兴伊措
(LOC), and unintended connectivity between two MEPs (e.g. mismerging or misconnection or unexpected MEP).
The Remote Defect Indication (RDI) is an indicator that is
transmitted by a MEP to communicate to its peer MEP that a signal
fail condition exists. RDI is only ud for bidirectional connections and is associated with proactive CC & CV packet generation.
This document specifies the BFD extension and behavior to satisfy the CC, proactive CV monitoring and the RDI functional requirements for
bi-directional paths. Procedures for uni-directional paths are for小通草的功效与作用
further study.
The mechanisms specified in this document are restricted to BFD
asynchronous mode.
Allan et al., Expires January 12, 2011 [Page 3]
Internet-Draft draft-ietf-mpls-tp-cc-cv-rdi-01 July 2010 1.1. Authors
David Allan, John Drake, George Swallow, Annamaria Fulignoli, Sami Boutros, Siva Sivabalan, Davi
d Ward, Martin Vigoureux.
2. Conventions ud in this document
2.1. Terminology
ACH: Associated Channel Header师生情
BFD: Bidirectional Forwarding Detection
CV: Connection Verification
GAL: Generalized Alert Label
LSR: Label Switching Router
MEG: Maintenance Entity Group
清如
MEP: Maintenance Entity Group End Point
MIP: Maintenance Entity Group Intermediate Point
MPLS-OAM: MPLS Operations, Administration and Maintenance
MPLS-TP: MPLS Transport Profile
MPLS-TP LSP: Uni-directional or Bidirectional Label Switch Path reprenting a circuit
MS-PW: Multi-Segment PudoWire
NMS: Network Management System
PW: Pudo Wire
RDI: Remote Defect Indication.
TTL: Time To Live
TLV: Type Length Value
2.2. Issues for discussion
1) Requirement for additional BFD diagnostic codes?
Allan et al., Expires January 12, 2011 [Page 4]
Internet-Draft draft-ietf-mpls-tp-cc-cv-rdi-01 July 2010 1. When periodicity of CV cannot be supported
3. MPLS CC, proactive CV and RDI Mechanism using BFD
This document propos distinct encapsulations and code points for
BFD depending on whether the mode of operation is CC or CV:
o CC mode: defines a new code point in the Associated Channel Header (ACH) described in [2].In this mode Continuity Check and RDI
functionalities are supported.
o CV mode: defines a new code point in the Associated Channel Header (ACH) described in [2]. Under MPLS label stack, the ACH with "MPLS Proactive CV" code point indicates that the message is an MPLS BFD proactive CV and CC message.
o RDI: is communicated via the BFD state field in BFD CC and CV
messages. It is not a distinct PDU.
3.1. ACH code points for CC and proactive CV
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 1|Version| Flags |0xHH BFD CC/CV Code Point |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: ACH Indication of MPLS-TP Connection Verification
The first nibble (0001b) indicates the ACH.
The version and the flags are t to 0 as specified in [2].
The code point is either
-
BFD CC code point = 0xHH. [HH to be assigned by IANA from the PW
Associated Channel Type registry.] or,
- BFD proactive CV code point = 0xHH. [HH to be assigned by IANA from the PW Associated Channel Type registry.]
Both CC and CV modes apply to PWs, MPLS LSPs (including tandem
connection monitoring), and Sections.
It’s possible to run BFD in CC mode on some transport paths and BFD
in CV mode on other transport paths. For a given Maintenance Entity
Group (MEG) only one mode can be ud. A MEP that is configured to Allan et al., Expires January 12, 2011 [Page 5]
