Network Working Group                                            M. Chen
Internet-Draft                              Huawei Technologies Co., Ltd
Updates: 4379 (if approved)                                       P. Pan
Intended status: Standards Track                                Infinera
Expires: March 31, 2012                                     C. Pignataro
                                                                R. Asati
                                                                   Cisco
                                                      September 28, 2011


        Label Switched Path (LSP) Ping for IPv6 Pseudowire FECs
                  draft-chen-mpls-ipv6-pw-lsp-ping-02

Abstract

   Multi-Protocol Label Switching (MPLS) Label Switched Path (LSP) Ping
   and Traceroute mechanisms are commonly used to detect and isolate
   data plane failures in all MPLS LSPs including Pseudowire (PW) LSPs.
   The PW LSP Ping and Traceroute elements, however, are not specified
   for IPv6 address usage.

   Specifically, the Pseudowire FEC sub-TLVs for the Target FEC Stack in
   the LSP Ping and Traceroute mechanism are implicitly defined only for
   IPv4 Provider Edge (PEs) routers, and are not applicable for the case
   where PEs use IPv6 addresses.  There is, additionally, a degree of
   potential ambiguity in the specification of these sub-TLVs since the
   address family is not explicitly specified but it is to be inferred
   from the sub-TLV length.

   This document updates RFC4379 to explicitly constraint these existing
   PW FEC sub-TLVs for IPv4 LDP sessions, and extends Pseudowire LSP
   Ping to the IPv6 scenario where an IPv6 LDP session is used to signal
   the Pseudowire (i.e., where the Sender's and Receiver's IP addresses
   are IPv6 addresses.)  This is done by defining two new LSP Ping sub-
   TLVs for IPv6 Pseudowire FECs.

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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   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
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   This Internet-Draft will expire on March 31, 2012.

Copyright Notice

   Copyright (c) 2011 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
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   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.


























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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 4
   2.  IPv4 Pseudowire Sub-TLVs  . . . . . . . . . . . . . . . . . . . 4
   3.  IPv6 Pseudowire Sub-TLVs  . . . . . . . . . . . . . . . . . . . 5
     3.1.  IPv6 FEC 128 Pseudowire Sub-TLV . . . . . . . . . . . . . . 5
     3.2.  IPv6 FEC 129 Pseudowire Sub-TLV . . . . . . . . . . . . . . 6
   4.  Summary of Changes  . . . . . . . . . . . . . . . . . . . . . . 7
   5.  Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
   7.  Security Considerations . . . . . . . . . . . . . . . . . . . . 8
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 8
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 8
     9.1.  Normative References  . . . . . . . . . . . . . . . . . . . 8
     9.2.  Informative References  . . . . . . . . . . . . . . . . . . 8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 8



































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1.  Introduction

   Multi-Protocol Label Switching (MPLS) Label Switched Path (LSP) Ping
   and Traceroute are defined in [RFC4379].  This mechanism can be used
   to detect and isolate data plane failures in all MPLS Label Switched
   Paths (LSPs) including Pseudowires (PWs).  Currently, three PW
   related Target Forwarding Equivalence Class (FEC) sub-TLVs (FEC 128
   Pseudowire-Deprecated, FEC 128 Pseudowire-Current, and FEC 129
   Pseudowire) are defined (see Section 3.2 of [RFC4379]).  These sub-
   TLVs contain the source and destination addresses of the target LDP
   session, and currently only IPv4 target LDP session is covered.
   Despite the fact that the IP address family is not explicit in the
   sub-TLV definition, this can be inferred indirectly only calculating
   the Length of the sub-TLVs.  When IPv6 target LDP session is used,
   these existing sub-TLVs can not therefore be used.  Additionally, all
   other sub-TLVs are defined in pairs, one for IPv4 and another for
   IPv6, and not for PW sub-TLVs.

   This document updates [RFC4379] to make explicit the IPv4 nature of
   the existing PW sub-TLVs, and also defines two new Target FEC sub-
   TLVs (IPv6 FEC 128 Pseudowire sub-TLV and IPv6 FEC 129 Pseudowire
   sub-TLV) to extend the application of PW LSP Ping and Traceroute to
   the IPv6 usage when an IPv6 LDP session [I-D.ietf-mpls-ldp-ipv6] is
   used to signal the Pseudowire.  Note that FEC 128 Pseudowire
   (Deprecated) is not defined for IPv6 in this document.


2.  IPv4 Pseudowire Sub-TLVs

   This document updates Section 3.2 and Sections 3.2.8 through 3.2.10
   of [RFC4379] as follows and as indicated in Section 4 and Section 6.
   This is done to avoid any potential ambiguity, confusion, and
   backwards compatibility issues.

   Sections 3.2.8 through 3.2.10 of [RFC4379] list the PW sub-TLVs and
   state:

      "FEC 128" Pseudowire (Deprecated)

      "FEC 128" Pseudowire

      "FEC 129" Pseudowire

   These names and titles are now changed to:

      IPv4 "FEC 128" Pseudowire (Deprecated)





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      IPv4 "FEC 128" Pseudowire

      IPv4 "FEC 129" Pseudowire

   Additionally, when referring to the PE addresses, these three
   sections state:

      Sender's PE Address

      Remote PE Address

   These are now updated to say:

      Sender's PE IPv4 Address

      Remote PE IPv4 Address


3.  IPv6 Pseudowire Sub-TLVs

3.1.  IPv6 FEC 128 Pseudowire Sub-TLV

   IPv6 FEC 128 Pseudowire sub-TLV has the consistent structure with FEC
   128 Pseudowire sub-TLV as described in Section 3.2.9 of [RFC4379].
   The encoding of IPv6 FEC 128 Pseudowire sub-TLV is 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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      IPv6 FEC 128 PW Type     |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                   Sender's PE IPv6 Address                    ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                    Remote PE IPv6 Address                     ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                             PW ID                             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |            PW Type            |          Must Be Zero         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 1: IPv6 FEC 128 Pseudowire

   IPv6 FEC 128 PW: TBD.

   Length: it defines the length in octets of the value field of the
   sub-TLV and its value is 38.




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   Sender's PE IPv6 Address: The source IP address of the target IPv6
   LDP session.

   Remote PE IPv6 Address: The destination IP address of the target IPv6
   LDP session.

   PW ID: Same as FEC 128 Pseudowire [RFC4379].

   PW Type: Same as FEC 128 Pseudowire [RFC4379].

3.2.  IPv6 FEC 129 Pseudowire Sub-TLV

   IPv6 FEC 129 Pseudowire sub-TLV has the consistent structure with FEC
   129 Pseudowire sub-TLV as described in Section 3.2.10 of [RFC4379].
   The encoding of IPv6 FEC 129 Pseudowire is 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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      IPv6 FEC 129 PW Type     |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                   Sender's PE IPv6 Address                    ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                    Remote PE IPv6 Address                     ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |            PW Type            |   AGI Type    |  AGI Length   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                           AGI Value                           ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   AII Type    |  SAII Length  |      SAII Value               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                    SAII Value (continued)                     ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   AII Type    |  TAII Length  |      TAII Value               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                    TAII Value (continued)                     ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  TAII (cont.) |  0-3 octets of zero padding                   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 2: IPv6 FEC 129 Pseudowire

   IPv6 FEC 129 PW: TBD.

   The Length of this TLV is 40 + AGI length + SAII length + TAII
   length.  Padding is used to make the total length a multiple of 4;
   the length of the padding is not included in the Length field.



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   Sender's PE IPv6 Address: The source IP address of the target IPv6
   LDP session.

   Remote PE IPv6 Address: The destination IP address of the target IPv6
   LDP session.

   The other fields are same as FEC 129 Pseudowire [RFC4379].


4.  Summary of Changes

   Section 3.2 of [RFC4379] tabulates all the sub-TLVs for the Target
   FEC Stack.  Per the change described in Section 2 and Section 3, the
   table would show the following:

   Sub-Type       Length        Value Field
   --------       ------        -----------
     ...
          9           10        IPv4 "FEC 128" Pseudowire (deprecated)
         10           14        IPv4 "FEC 128" Pseudowire
         11          16+        IPv4 "FEC 129" Pseudowire
     ...
        TBD           38        IPv6 "FEC 128" Pseudowire
        TBD          40+        IPv6 "FEC 129" Pseudowire


5.  Operation

   This document does not define any new procedures.  The process
   described in [RFC4379] MUST be used.


6.  IANA Considerations

   IANA is requested to perform the following assignments in the "Multi-
   Protocol Label Switching (MPLS) Label Switched Paths (LSPs) Ping
   Parameters" registry, "TLVs and sub-TLVs" sub-registry.

   [RFC Editor: To be REMOVED prior to publication.  This registration
   should take place at <http://www.iana.org/assignments/
   mpls-lsp-ping-parameters/
   mpls-lsp-ping-parameters.xml#mpls-lsp-ping-parameters-7>]

   Update the Value fields of these three Sub-TLVs, adding the "IPv4"
   qualifier (see Section 2), and update the Reference to point to this
   document:





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   Type       Sub-Type        Value Field
   ----       --------        -----------
      1            9          IPv4 "FEC 128" Pseudowire (Deprecated)
      1           10          IPv4 "FEC 128" Pseudowire
      1           11          IPv4 "FEC 129" Pseudowire

   Create two new entries for the Sub-Type field of Target FEC TLV (see
   Section 3):

   Type       Sub-Type        Value Field
   ----       --------        -----------
      1         TBD1          IPv6 "FEC 128" Pseudowire
      1         TBD2          IPv6 "FEC 129" Pseudowire


7.  Security Considerations

   This draft does not introduce any new security issues, the security
   mechanisms defined in [RFC4379] apply here.


8.  Acknowledgements

   The authors gratefully acknowledge review and comments of Vanson Lim
   and Tom Petch.


9.  References

9.1.  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.

9.2.  Informative References

   [I-D.ietf-mpls-ldp-ipv6]
              Asati, R., Manral, V., Papneja, R., and C. Pignataro,
              "Updates to LDP for IPv6", draft-ietf-mpls-ldp-ipv6-05
              (work in progress), August 2011.







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Authors' Addresses

   Mach(Guoyi) Chen
   Huawei Technologies Co., Ltd
   No. 3 Xinxi Road, Shang-di, Hai-dian District
   Beijing  100085
   China

   Email: mach@huawei.com


   Ping Pan
   Infinera
   US

   Email: ppan@infinera.com


   Carlos Pignataro
   Cisco Systems
   7200-12 Kit Creek Road
   Research Triangle Park, NC  27709
   US

   Email: cpignata@cisco.com


   Rajiv Asati
   Cisco Systems
   7025-6 Kit Creek Road
   Research Triangle Park, NC  27709
   US

   Email: rajiva@cisco.com

















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