[Docs] [txt|pdf|xml|html] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-nitinb-mpls-tp-lsp-ping-bfd-procedures) 00 01

Network Working Group                                    N. Bahadur, Ed.
Internet-Draft                                          R. Aggarwal, Ed.
Intended status: Standards Track                            D. Ward, Ed.
Expires: February 23, 2011                        Juniper Networks, Inc.
                                                               T. Nadeau
                                                                      BT
                                                             N. Sprecher
                                                           Y. Weingarten
                                                  Nokia Siemens Networks
                                                         August 22, 2010


                LSP-Ping and BFD encapsulation over ACH
             draft-ietf-mpls-tp-lsp-ping-bfd-procedures-01

Abstract

   LSP-Ping and BFD for MPLS are existing and widely deployment OAM
   mechanisms for MPLS LSPs.  This document describes an ACH
   encapsulation for LSP-Ping, that would enable use of LSP-Ping for
   networks where IP addressing is not in use.  This document also
   clarifies the use of BFD for MPLS LSPs using ACH encapsulation, when
   IP addressing may not be available and/or it may not be desirable to
   encapsulate BFD packets in IP.

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 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 use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt.

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on February 23, 2011.




Bahadur, et al.         Expires February 23, 2011               [Page 1]


Internet-Draft   LSP-Ping and BFD encapsulation over ACH     August 2010


Copyright Notice

   Copyright (c) 2010 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 BSD License.


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
     1.1.  Conventions used in this document . . . . . . . . . . . . . 3
     1.2.  LSP-Ping and BFD over ACH . . . . . . . . . . . . . . . . . 3
   2.  LSP-Ping extensions . . . . . . . . . . . . . . . . . . . . . . 3
     2.1.  LSP-Ping packet over ACH for LSPs . . . . . . . . . . . . . 3
     2.2.  LSP-Ping packet over ACH for PWs  . . . . . . . . . . . . . 4
     2.3.  Source Address TLV  . . . . . . . . . . . . . . . . . . . . 4
     2.4.  MEP and MIP Identifier  . . . . . . . . . . . . . . . . . . 5
   3.  Running BFD over MPLS-TP LSPs . . . . . . . . . . . . . . . . . 5
   4.  Security Considerations . . . . . . . . . . . . . . . . . . . . 6
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
     5.1.  New ACH Channel Types . . . . . . . . . . . . . . . . . . . 7
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 7
     6.1.  Normative References  . . . . . . . . . . . . . . . . . . . 7
     6.2.  Informative References  . . . . . . . . . . . . . . . . . . 7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 8

















Bahadur, et al.         Expires February 23, 2011               [Page 2]


Internet-Draft   LSP-Ping and BFD encapsulation over ACH     August 2010


1.  Introduction

   LSP-Ping [RFC4379] and BFD for MPLS [RFC5884] are OAM mechanisms for
   MPLS LSPs.  This document describes an ACH encapsulation for LSP-Ping
   for networks that do not use IP addressing.  When IP addressing is in
   use, the LSP-Ping procedures specified in [RFC4379] apply as is.
   This document also clarifies the use of BFD for MPLS LSPs using ACH
   encapsulation [RFC5586], when IP addressing may not be available
   and/or it may not be desirable to encapsulate BFD packets in IP.

1.1.  Conventions used in this document

   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].

1.2.  LSP-Ping and BFD over ACH

   In certain MPLS-TP deployment scenarios IP addressing might not be
   available or it may be preferred to use non-IP encapsulation for LSP-
   Ping and BFD packets.  The remainder of this document defines
   extensions to LSP-Ping and procedures for using BFD, for such
   scenarios.

   Section 2.1 and Section 2.2 describe a new ACH code-point for
   performing LSP-Ping over ACH.  Section 3 describes procedures for
   using BFD over ACH.


2.  LSP-Ping extensions

2.1.  LSP-Ping packet over ACH for LSPs

   [RFC5586] defines an ACH mechanism for MPLS LSPs.  This document
   defines a new ACH channel type for LSP-Ping, when IP addressing is
   not in use, for LSP-Ping over associated bi-directional LSPs and co-
   routed bi-directional LSPs.  ACH TLVs MAY be associated with this
   channel type.

       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 2
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |0 0 0 1|Version|   Reserved    |     LSP-Ping Channel Type     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                    Figure 1: LSP-Ping ACH Channel Type




Bahadur, et al.         Expires February 23, 2011               [Page 3]


Internet-Draft   LSP-Ping and BFD encapsulation over ACH     August 2010


   When ACH header is used, an LSP-Ping packet will look as follows:

       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 2
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                         MPLS Label stack                      |
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                          GAL                                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |0 0 0 1|Version|   Reserved    |     LSP-Ping Channel Type     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                      ACH TLV Header                           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                          ACH TLVs                             |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                      LSP-Ping payload                         |
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                    Figure 2: LSP-Ping packet with ACH

   When using LSP-Ping over the ACH header, the LSP-Ping Reply mode
   [RFC4379] in the LSP-Ping echo request MUST be set to 4 (Reply via
   application level control channel).

2.2.  LSP-Ping packet over ACH for PWs

   [RFC4385] defines an PW-ACH mechanism for pseudowires.  The ACH
   channel type for LSP-Ping defined in Section 2.1 will be re-used for
   pseudowires so that IP addressing is not needed when using LSP-Ping
   OAM over pseudowires.

2.3.  Source Address TLV

   When sending LSP-Ping packets using ACH, without IP encapsulation,
   there MAY be a need to identify the source address of the packet.
   This source address will be specified via the Source Address TLV,
   being defined in [I-D.ietf-mpls-tp-ach-tlv].  No more than 1 source
   address TLV MAY be present in a LSP-Ping packet.  The source address
   MUST specify the address of the originator of the packet.  If more
   than 1 such TLV is present in a LSP-Ping request packet, then an
   error code of 1 (Malformed echo request received), [ Section 3.1
   [RFC4379]], SHOULD be returned.  If more than 1 source address TLV is
   present, then the packet SHOULD be dropped without further



Bahadur, et al.         Expires February 23, 2011               [Page 4]


Internet-Draft   LSP-Ping and BFD encapsulation over ACH     August 2010


   processing.

2.4.  MEP and MIP Identifier

   When sending LSP-Ping packets using ACH, there MAY be a need to
   identify the maintenance end point (MEP) and/or the maintenance
   intermediate point (MIP) being monitored
   [I-D.ietf-mpls-tp-rosetta-stone].  The MEP/MIP identifiers defined in
   [I-D.ietf-mpls-tp-identifiers] MAY be carried in the ACH TLVs
   [I-D.ietf-mpls-tp-ach-tlv] for identification.


3.  Running BFD over MPLS-TP LSPs

   [RFC5884] describes how BFD can be used for Continuity Check of MPLS
   LSPs.  The procedures described in [RFC5884] MUST be used when IP
   encapsulation is in use.  This section clarifies the usage of BFD in
   the context of MPLS-TP LSPs when it is not desirable to use IP
   encapsulation.  When using BFD over MPLS-TP LSPs, the BFD
   discriminator MUST either be signaled via LSP-Ping or be statically
   configured.  The BFD packets MUST be sent over ACH when IP
   encapsulation is not used.

   This document defines a new ACH channel type for BFD over G-ACH, when
   IP addressing is not in use, for running BFD over associated bi-
   directional LSPs and co-routed bi-directional LSPs.  ACH TLVs MAY be
   associated with this channel type.

       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 2
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |0 0 0 1|Version|   Reserved    |  BFD over G-ACH Channel Type  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                   Figure 3: BFD over G-ACH Channel Type

   BFD packets, for both directions, MUST be sent over the MPLS-TP LSP
   and IP forwarding SHOULD NOT be used for the reverse path.  The
   format of a BFD packet when using it as an OAM tool for MPLS-TP LSPs
   SHOULD be as follows:










Bahadur, et al.         Expires February 23, 2011               [Page 5]


Internet-Draft   LSP-Ping and BFD encapsulation over ACH     August 2010


       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 2
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                         MPLS Label stack                      |
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                          GAL                                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |0 0 0 1|Version|   Reserved    |  BFD over G-ACH Channel Type  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                      ACH TLV Header                           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                            ACH TLVs                           |
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                          BFD payload                          |
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                  Figure 4: BFD packet over MPLS-TP LSPs

   [RFC5885] specifies how BFD can be used over MPLS PWs.  One MAY use
   BFD over G-ACH channel type to run BFD over PWs if ACH TLV support is
   needed.

   BFD supports continuous fault monitoring and thus meets the pro-
   active Continuity Check and verification requirement specified in
   [RFC5860].  BFD SHOULD be run pro-actively.  This function SHOULD be
   performed between End Points (MEPs) of PWs, LSPs and Sections.  For
   point to multipoint Continuity Check, there is work in progress on
   using BFD for P2MP MPLS LSPs ( [I-D.katz-ward-bfd-multipoint]) and
   this can be leveraged for MPLS-TP LSPs as well.  Failure of a BFD
   session over a LSP can be used to trigger protection switching or
   other fault remedial procedures.

   When sending BFD packets using ACH, there MAY be a need to identify
   the maintenance end point (MEP) being monitored.  The MEP identifier
   defined in [I-D.ietf-mpls-tp-identifiers] can be carried in the ACH
   TLVs [I-D.ietf-mpls-tp-ach-tlv] for identification.


4.  Security Considerations

   The draft does not introduce any new security considerations.  Those
   discussed in [RFC4379] are also applicable to this document.





Bahadur, et al.         Expires February 23, 2011               [Page 6]


Internet-Draft   LSP-Ping and BFD encapsulation over ACH     August 2010


5.  IANA Considerations

5.1.  New ACH Channel Types

   New Channels type are defined in Section 2.1 and Section 3.  IANA is
   requested to assign new values from the "PW Associated Channel Type"
   registry, as per IETF consensus policy.

       Value    Meaning
       -----    -------
        TBD     Associated Channel carries LSP-Ping packet
        TBD     Associated Channel carries BFD over G-ACH



6.  References

6.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC4379]  Kompella, K. and G. Swallow, "Detecting Multi-Protocol
              Label Switched (MPLS) Data Plane Failures", RFC 4379,
              February 2006.

   [RFC4385]  Bryant, S., Swallow, G., Martini, L., and D. McPherson,
              "Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for
              Use over an MPLS PSN", RFC 4385, February 2006.

6.2.  Informative References

   [I-D.ietf-mpls-tp-ach-tlv]
              Boutros, S., Bryant, S., Sivabalan, S., Swallow, G., Ward,
              D., and V. Manral, "Definition of ACH TLV Structure",
              draft-ietf-mpls-tp-ach-tlv-02 (work in progress),
              March 2010.

   [I-D.ietf-mpls-tp-identifiers]
              Bocci, M. and G. Swallow, "MPLS-TP Identifiers",
              draft-ietf-mpls-tp-identifiers-02 (work in progress),
              July 2010.

   [I-D.ietf-mpls-tp-rosetta-stone]
              Sprecher, N., "A Thesaurus for the Terminology used in
              Multiprotocol Label Switching Transport Profile (MPLS-TP)
              drafts/RFCs and ITU-T's Transport Network
              Recommendations.", draft-ietf-mpls-tp-rosetta-stone-02



Bahadur, et al.         Expires February 23, 2011               [Page 7]


Internet-Draft   LSP-Ping and BFD encapsulation over ACH     August 2010


              (work in progress), May 2010.

   [I-D.katz-ward-bfd-multipoint]
              Katz, D. and D. Ward, "BFD for Multipoint Networks",
              draft-katz-ward-bfd-multipoint-02 (work in progress),
              February 2009.

   [RFC5586]  Bocci, M., Vigoureux, M., and S. Bryant, "MPLS Generic
              Associated Channel", RFC 5586, June 2009.

   [RFC5860]  Vigoureux, M., Ward, D., and M. Betts, "Requirements for
              Operations, Administration, and Maintenance (OAM) in MPLS
              Transport Networks", RFC 5860, May 2010.

   [RFC5884]  Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow,
              "Bidirectional Forwarding Detection (BFD) for MPLS Label
              Switched Paths (LSPs)", RFC 5884, June 2010.

   [RFC5885]  Nadeau, T. and C. Pignataro, "Bidirectional Forwarding
              Detection (BFD) for the Pseudowire Virtual Circuit
              Connectivity Verification (VCCV)", RFC 5885, June 2010.


Authors' Addresses

   Nitin Bahadur (editor)
   Juniper Networks, Inc.
   1194 N. Mathilda Avenue
   Sunnyvale, CA  94089
   US

   Phone: +1 408 745 2000
   Email: nitinb@juniper.net
   URI:   www.juniper.net


   Rahul Aggarwal (editor)
   Juniper Networks, Inc.
   1194 N. Mathilda Avenue
   Sunnyvale, CA  94089
   US

   Phone: +1 408 745 2000
   Email: rahul@juniper.net
   URI:   www.juniper.net






Bahadur, et al.         Expires February 23, 2011               [Page 8]


Internet-Draft   LSP-Ping and BFD encapsulation over ACH     August 2010


   David Ward (editor)
   Juniper Networks, Inc.
   1194 N. Mathilda Avenue
   Sunnyvale, CA  94089
   US

   Phone: +1 408 745 2000
   Fax:
   Email: dward@juniper.net
   URI:   www.juniper.net


   Thomas D. Nadeau
   BT
   BT Centre
   81 Newgate Street
   London  EC1A 7AJ
   United Kingdom

   Email: tom.nadeau@bt.com


   Nurit Sprecher
   Nokia Siemens Networks
   3 Hanagar St. Neve Ne'eman B
   Hod Hasharon  45241
   Israel

   Phone: +972-9-775 1229
   Email: nurit.sprecher@nsn.com


   Yaacov Weingarten
   Nokia Siemens Networks
   3 Hanagar St. Neve Ne'eman B
   Hod Hasharon  45241
   Israel

   Phone: +972-9-775 1827
   Email: yaacov.weingarten@nsn.com











Bahadur, et al.         Expires February 23, 2011               [Page 9]


Html markup produced by rfcmarkup 1.121, available from https://tools.ietf.org/tools/rfcmarkup/