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PWE3 Working Group                                    Luca Martini (Ed.)
Internet Draft                                        Cisco Systems Inc.
Expires: December 2006                               Matthew Bocci (Ed.)
                                                      Florin Balus (Ed.)

                                                               June 2006

            Dynamic Placement of Multi Segment Pseudo Wires


Status of this Memo

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   There is a requirement for service providers to be able to extend the
   reach of pseudo wires (PW) across multiple Packet Switched Network
   domains. A Multi-Segment PW is defined as a set of two or more
   contiguous PW segments that behave and function as a single point-
   to-point PW. This document describes extensions to the PW control
   protocol to dynamically place the segments of the multi segment
   pseudo wire among a set of Provider Edge (PE) routers.

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Table of Contents

    1        Specification of Requirements  ........................   3
    2        Major Co-authors  .....................................   3
    3        Acknowledgements  .....................................   3
    4        Introduction  .........................................   3
    4.1      Scope  ................................................   3
    4.2      Terminology  ..........................................   4
    4.3      Architecture Overview  ................................   4
    5        Applicability  ........................................   6
    5.1      Requirements Addressed  ...............................   6
    5.2      Changes to Existing PW Signaling  .....................   6
    6        PW layer 2 addressing  ................................   6
    6.1      Attachment Circuit Addressing  ........................   7
    6.2      S-PE addressing  ......................................   7
    7        Dynamic placement of MS-PWs  ..........................   8
    7.1      Pseudo wire routing procedures  .......................   8
    7.1.1    AII PW routing table Lookup aggregation rules  ........   8
    7.1.2    PW Static Route  ......................................   9
    7.1.3    Dynamic advertisement with BGP  .......................   9
    7.2      LDP Signaling  ........................................  10
    7.2.1    MS-PW Bandwidth Signaling  ............................  10
    7.2.2    Active/Passive T-PE Election Procedure  ...............  12
    7.2.3    Detailed Signaling Procedures  ........................  12
    7.2.4    Support for Explicit PW Path  .........................  13
    8        Failure Handling Procedures  ..........................  13
    8.1      PSN Failures  .........................................  13
    8.2      S-PE Failures  ........................................  14
    9        Operations and Maintenance (OAM)  .....................  14
   10        Security Considerations  ..............................  14
   11        IANA Considerations  ..................................  15
   11.1      LDP Status Codes  .....................................  15
   11.2      BGP SAFI  .............................................  15
   12        Full Copyright Statement  .............................  15
   13        Intellectual Property Statement  ......................  16
   14        Normative References  .................................  16
   15        Informative References  ...............................  17
   16        Author Information  ...................................  17

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1. Specification of Requirements

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in RFC 2119

2. Major Co-authors

   The editors gratefully acknowledge the following additional co-
   authors:  Mustapha Aissaoui, Nabil Bitar, Mike Loomis, David McDysan,
   Chris Metz, Andy Malis, Jason Rusmeisel, Himanshu Shah, Jeff

3. Acknowledgements

   The editors also gratefully acknowledge the input of the following
   people:  Mike Ducket, Paul Doolan, Prayson Pate, Ping Pan, Vasile
   Radoaca, Yeongil Seo, Yetik Serbest, Yuichiro Wada.

4. Introduction

4.1. Scope

   [MS-REQ] describes the service provider requirements for extending
   the reach of pseudo-wires across multiple PSN domains. This is
   achieved using a Multi-segment Pseudo-Wire (MS-PW). A MS-PW is
   defined as a set of two or more contiguous PW segments that behave
   and function as a single point-to-point PW. This architecture is
   described in [MS-ARCH].

   The procedures for establishing PWs that extend across a single PWE3
   domain are described in [RFC4447], while procedures for setting up
   PWs across multiple domains, or control planes are described in [PW-

   The purpose of this draft is to specify extensions to the PWE3
   control protocol [RFC4447], and [PW-SEG] procedures, to enable
   multi-segment PWs to be automatically placed. The proposed procedures
   follow the guidelines defined in [RFC3036bis] and enable the reuse of
   existing TLVs, and procedures defined for SS-PWs in [RFC4447].

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4.2. Terminology

   [MS-ARCH] provides terminology for multi-segment pseudo wires.

   This document defines the following additional terms:

     - Source Terminating PE (ST-PE). A Terminating PE (T-PE), which
       assumes the active signaling role and initiates the signaling for
       multi-segment PW.
     - Target Terminating PE (TT-PE). A Terminating PE (T-PE) that
       assumes the passive signaling role. It waits and responds to the
       multi-segment PW signaling message in the reverse direction.
     - Forward Direction: ST-PE to TT-PE.
     - Reverse Direction: TT-PE to ST-PE
     - Forwarding Direction: Direction of control plane, signaling flow
     - Pseudo wire Routing (PW routing). The dynamic placement of SS-PWs
       that compose an MS-PW, as well as the automatic selection of S-

4.3. Architecture Overview

   The following figure describes the reference models which are derived
   from [MS-ARCH] to support PW emulated services across multi-segment

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       Native   |<-------------Pseudo Wire----------->|  Native
       Service  |                                     |  Service
        (AC)    |     |<-PSN1-->|     |<-PSN2-->|     |   (AC)
          |     V     V         V     V         V     V     |
          |     +-----+         +-----+         +-----+
   +----+ |     |T-PE1|=========|S-PE1|=========|T-PE2|     |    +----+
   |    |-------|.....PW.Seg't1........PW Seg't3......|----------|    |
   | CE1| |     |     |         |     |         |     |     |    |CE2 |
   |    |-------|.....PW.Seg't2.......|PW Seg't4......|----------|    |
   +----+ |     |     |=========|     |=========|     |     |    +----+
     ^          +-----+         +-----+         +-----+          ^
     |      Provider Edge 1       ^        Provider Edge 2       |
     |                            |                              |
     |                            |                              |
     |                    PW switching point                     |
     |                                                           |
     |<------------------- Emulated Service -------------------->|

                 Figure 1: PW switching Reference Model

   Figure 1 shows the architecture for a simple multi-segment case. T-
   PE1 and T-PE2 provide PWE3 to CE1 and CE2. These PEs reside in
   different PSNs. A PSN tunnel extends from T-PE1 to S-PE1 across PSN1,
   and a second PSN tunnel extends from S-PE1 to T-PE2 across PSN2. PWs
   are used to connect the attachment circuits (ACs) attached to T-PE1
   to the corresponding AC attached to T-PE2. A PW on the tunnel across
   PSN1 is connected to a PW in the tunnel across PSN2 at S-PE1 to
   complete the multi-segment PW (MS-PW) between T-PE1 and T-PE2. S-PE1
   is therefore the PW switching point and will be referred to as the PW
   switching provider edge (S-PE). PW Segment 1 and PW Segment 3 are
   segments of the same MS-PW while PW Segment 2 and PW Segment 4 are
   segments of another pseudo-wire. PW segments of the same MS-PW (e.g.,
   PW1 and PW3) MUST be of the same PW type, and PSN tunnels (e.g., PSN1
   and PSN2) can be the same or different technology. An S-PE switches
   an MS-PW from one segment to another based on the PW identifiers. (
   PWid , or AII ) How the Pw PDUs are switched at the S-PE depends on
   the PSN tunnel technology: in case of an MPLS PSN to another MPLS PSN
   PW switching the operation is a standard MPLs label switch operation.

   Note that although Figure 1 only shows a single S-PE, a PW may
   transit more one S-PE along its path. For instance, in the multi-
   provider case, there can be an S-PE at the border of one provider
   domain and another S-PE at the border of the other provider domain.

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5. Applicability

   In this document we describe the case where the PSNs carrying the
   SS-PW are only MPLS PSNs using the generalized FEC 129. Furthermore,
   we consider the case of a ST-PE and/or TT-PE supporting FEC 128 only
   and which establish a MS-PW through a network of FEC 129 S-PEs.
   Interactions with an IP PSN using L2TPv3 as described in [PW-SEG]
   section 7.4 are left for further study.

5.1. Requirements Addressed

   Specifically the following requirements are addressed - see [MS-REQ]:
     - Dynamic End-to-end Signaling
     - Scalability and Inter-domain Signaling and Routing
     - Minimal number of provisioning touches (provisioning only at the
     - Same set of T-PEs/S-PEs for both directions of a MS-PWs
     - QoS Signaling, Call Admission Control
     - Resiliency
     - End-to-end negotiation of OAM Capability

5.2. Changes to Existing PW Signaling

   The procedures described in this document make use of existing LDP
   TLVs and related PW signaling procedures described in [RFC4447] and
   [PW-SEG]. Only an optional Bandwidth TLV is added to address the QoS
   Signaling requirements (see "MS-PW Next Hop Bandwidth Signaling"
   section for details).

6. PW layer 2 addressing

   Single segment pseudo wires on an MPLS PSN use the PWID for
   addressing a PW using FEC 128, and Attachment circuit identifiers for
   a PW using FEC 129. In the case of an automatically placed MS-PW,
   there is a requirement to have individual global addresses assigned
   to PW attachment circuits, for reachability , and manageability of
   the PW. Referencing figure 1 above, individual globally unique
   addresses MUST be allocated to all the ACs , and S-PEs composing an

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6.1. Attachment Circuit Addressing

   The attachment circuit addressing is derived from [AII] AII type 2
   shown here:

    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
   |  AII Type=02  |    Length     |        Global ID              |
   |       Global ID (contd.)      |        Prefix                 |
   |       Prefix (contd.)         |        AC ID                  |
   |      AC ID                    |

   Implementations of the following procedure MUST interpret the AII
   type to determine the meaning the address format of the AII,
   irrespective of the number of segments in the MS-PW.

   A unique combination Global ID, Prefix, and AC ID parts of the AII
   type 2 will be assigned to each AC. In general the same global ID and
   prefix will be assigned for all ACs belonging to the same T-PE,
   however this is not a strict requirement. A particular T-PE might
   have more than one prefix assigned to it, and likewise a fully
   qualified AII with the same Global ID/Prefix but different AC IDs
   might belong to different T-PEs.

   For the purpose of MS-PW the AII MUST be globally unique across all
   interconnected PW domains.

6.2. S-PE addressing

   The T-PE may elect to select a known specific path along a set of S-
   PEs for a specific PW. This requires that each S-PE be uniquely
   addressable in terms of pseudo wires. For this purpose at least one
   AI address of the format similar to AII type 2 [AII] composed of the
   Global ID, and Prefix part only MUST be assigned to each S-PE.

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7. Dynamic placement of MS-PWs

   [PW-SEG] describes a procedure for connecting multiple pseudo wires
   together. This procedure requires each S-PE to be manually configured
   with the information required to terminate and initiate the SS-PW
   part of the MS-PW. The procedures in the following sections describe
   an method to extend [PW-SEG] by allowing the automatic selection of
   pre-defined S-PEs, and automatically setting up a MS-PW between two

   In this document we consider the case where the PSNs carrying the
   SS-PW are only MPLS PSNs using the generalized FEC 129. Interactions
   with an IP PSN using L2TPv3 as described in [PW-SEG] section 7.4 are
   left for further study.

7.1. Pseudo wire routing procedures

   The AII type 2 described above contains a Global ID, Prefix, and AC
   ID. The TAII is used by S-PEs to determine the next SS-PW destination
   for LDP signaling.

   Once an S-PE receives a PW Setup message containing a TAII with an
   AII that is not locally present, the S-PE performs a lookup in a
   local Layer 2 AII PW routing table. If this lookup results in an IP
   address of the next PE that advertised reachability information for
   the AII in question, then the S-PE will initiate the necessary LDP
   messaging procedure for setting up the next PW segment. If the AII PW
   routing table lookup does not result in a IP address of the next PE,
   the destination AII has become unreachable, and the PW MUST fail to
   setup. In this case a label release MUST be returned to the T-PE with
   a status message of "AII Unreachable".

   To allow for dynamic end-to-end signaling of MS-PWs, information must
   be present in S-PEs to support the determination of the next PW
   signaling hop.  Such information can be provisioned (static route
   equivalent) on each S-PE system or disseminated via regular routing
   protocols (e.g. BGP).

7.1.1. AII PW routing table Lookup aggregation rules

   All PEs capable of dynamic multi segment pseudowire path selection,
   must build a PW routing table to be used for PW next hop selection.

   The PW addressing scheme (AII type 2 in [AII]) consists of a Global
   Id, a 32 bit prefix and a 32 bit Attachment Circuit ID.

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   An aggregation scheme similar with the one used for classless IPv4
   addresses can be employed. An (8 bits) length mask is specified as a
   number ranging from 0 to 96 that indicates which Least Significant
   Bits (LSB) are ignored in the address field when performing the PW
   address matching algorithm.

    0        31 32    63 64    95 (bits)
   | Global ID | Prefix | AC ID  |

   During the signaling phase, the content of the (fully qualified) TAII
   type 2 field from the FEC129 TLV is compared against routes from the
   PW Routing table.  Similar with the IPv4 case, the route with the
   longest match is selected, determining the next signaling hop and
   implicitly the next PW Segment to be signaled.

7.1.2. PW Static Route

   For the purpose of determining the next signaling hop for a segment
   of the pseudo wire, the PEs MAY be provisioned with fixed route
   entries in the PW next hop routing table. The static PW entries will
   follow all the addressing rules and aggregation rules described in
   the previous sections.  The most common use of PW static provisioned
   routes is this example of the "default" route entry as follows:

   Global ID = 0 Prefix = 0 AC ID = 0 , Prefix Length = 0 Next Signaling
   Hop = S-PE1

7.1.3. Dynamic advertisement with BGP

   Any suitable routing protocol capable of carring external routing
   information may be used to propogate MS-PW path infomation among S-
   PE, and T-PE. However, T-PE, and S-PEs, MAY choose to use [RFC2858]
   to propagate PW address information throughout the PSN.

   In the case of the MS-PW if the Source T-PE knows apriori the address
   of the Terminating T-PE, there is no need to advertise a "fully
   qualified" address on a per PW Attachment Circuit. Only the T-PE
   Global ID, Prefix, and prefix length needs to be advertised as part
   of well known BGP procedures - see [RFC2858] and, [L2VPN-SIG].

   As PW Endpoints are provisioned in the T-PEs, the ST-PE will use this
   information to obtain the first S-PE hop (i.e., first BGP next hop)
   where the first PW segment will be established and subsequent S-PEs

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   will use the same information (i.e. the next BGP next-hop(s)) to
   obtain the next-signaling-hop(s) on the path to the TT-PE.

   The PW dynamic path NLRI is advertised in BGP UPDATE messages using
   the MP_REACH_NLRI and MP_UNREACH_NLRI attributes [RFC2858]. The [AFI,
   SAFI] value pair used to identify this NLRI is (AFI=25, SAFI=TBD).

   The Next Hop field of MP_REACH_NLRI attribute shall be interpreted as
   an IPv4 address, whenever the length of NextHop address is 4 octets,
   and as a IPv6 address, whenever the length of the NextHop address is
   16 octets.

   The NLRI field in the MP_REACH_NLRI and MP_UNREACH_NLRI is a prefix
   of 0 to 96 bits encoded as defined in section 4 of [RFC2858].

   This prefix is structured as follows:

    0        31 32    63 64    95 (bits)
   | Global ID | Prefix | AC ID  |

   Except for the default PW route, which is encoded as a 0 length
   prefix, the minimum prefix length is 32 bits.  As the Global ID field
   cannot be interpreted as a prefix.

7.2. LDP Signaling

   The LDP signaling procedures are described in [RFC4447] and expanded
   in [PW-SEG]. No new LDP Signaling components are required for setting
   up a basic automatically placed MS-PW. However some optional
   signaling extensions are described below.

7.2.1. MS-PW Bandwidth Signaling

   In the SS-PW case the PW QoS requirements may easily be met by
   selecting a MPLS PSN tunnel at the S-PE that meets the PW QoS
   requirements. However in the case of an automatically placed MS-PW
   the QoS requirements for a SS-PW not initiating on a T-PE MAY need to
   be indicated along with the MS-PW addressing. This is accomplished by
   including an OPTIONAL PW Bandwidth TLV.  The PW Bandwidth TLV is
   specified as follows:

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    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
   |1|0|     PW BW  TLV  (0x096E)   |         TLV  Length          |
   |                     Forward SENDER_TSPEC                      |
   |                     Reverse SENDER_TSPEC                      |

   The complete definitions of the content of the SENDER_TSPEC objects
   are found in [TSPEC] section 3.1. The forward SENDER_TSPEC refers to
   the datapath in the direction of ST-PE to TT-PE. The reverse
   SENDER_TSPEC refers to the data path in the direction TT-PE to ST-PE.

   In the forward direction, after a next hop selection is determined, a
   T/S-PE SHOULD reference the forward SENDER_TSPEC object to determine
   an appropriate PSN tunnel towards the next signaling hop. If such a
   tunnel exists, the MS-PW signaling procedures are invoked with the
   inclusion of the PW Bandwidth TLV.

   When an S/T-PE receives a PW Bandwidth TLV, once the PW next hop is
   selected, the S/T-PE MUST request the appropriate resources from the
   PSN.  The resources described in the reverse SENDER_TSPEC are
   allocated from the PSN toward the originator of the message or
   previous hop. When resources are allocated from the PSN for a
   specific PW, then the PSN SHOULD account for the PW usage of the

   In the case where PSN resources towards the previous hop are not
   available the following procedure MUST be followed:
        -i. The PSN MAY allocate more QoS resources, e.g. Bandwidth, to
            the PSN tunnel.
       -ii. The S-PE MAY attempt to setup another PSN tunnel to
            accommodate the new PW QoS requirements.
      -iii. If the S-PE cannot get enough resources to setup the segment
            in the MS-PW a label release MUST be returned to the
            previous hop with a status message of "Bandwidth resources

   In the latter case, the T-PE receiving the status message MUST also
   withdraw the corresponding PW label mapping for the opposite
   direction if it has already been successfully setup.

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7.2.2. Active/Passive T-PE Election Procedure

   When a MS-PW is signaled, Each T-PE might independently start
   signaling the MS-PW, this could result in a different path selected
   for each T-PE PW. To avoid this situation one of the T-PE MUST start
   the PW signaling ( active role ), while the other waits to receive
   the LDP label mapping before sending the respective PW LDP label
   mapping message. ( passive role ). The Active T-PE (the ST-PE) and
   the passive T-PE (the TT-PE) MUST be identified before signaling is
   initiated for a given MS-PW.

   The determination of which T-PE assume the active role SHOULD be done
   as follows: the SAII and TAII are compared as unsigned integers, if
   the SAII is bigger then the T-PE assumes the active role.

   The selection process to determine which T-PE assumes the active role
   MAY be superseded by manual provisioning.

   If a ST-PE receives a reply MS-PW setup message for a particular MS-
   PW from a PE that is not the next hop PE originally used, then the
   ST-PE MUST send a label release message, with a status code of
   "Duplicate AII", to the PE that originated the incorrect MS-PW reply
   setup message.

7.2.3. Detailed Signaling Procedures

   On receiving a label mapping message, the S-PE MUST inspect the FEC
   TLV. If the receiving node has no local AII matching the TAII for
   that label mapping then the S-PE will check if the FEC is already
   installed for the forward direction:
     - If it is already installed, and the received mapping was received
       from the same LDP peer where the forward LDP label mapping was
       sent, then this label mapping represents signaling in the reverse
       direction for this MS-PW segment.
     - Otherwise this represents signaling in the forward direction.

   For the forward direction:
        -i. Determine the next hop S-PE or T-PE according to the
            procedures above.
       -ii. Check that a PSN tunnel exists to the next hop S-PE or T-PE.
            If no tunnel exists to the next hop S-PE or T-PE the S-PE
            MAY attempt to setup a PSN tunnel.
      -iii. Check that a PSN tunnel exists to the previous hop. If no
            tunnel exists to the previous hop S-PE or T-PE the S-PE MAY
            attempt to setup a PSN tunnel.

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       -iv. If the S-PE cannot get enough PSN resources to setup the
            segment to the next or previous S-PE or T-PE, a label
            withdraw MUST be returned to the T-PE with a status message
            of "Resources Unavailable".
        -v. If the label mapping message contains a Bandwidth TLV,
            allocate the required resources on the PSN tunnels in the
            forward and reverse directions according to the procedures
       -vi. Allocate a new PW label for the forward direction.
      -vii. Install the FEC for the forward direction.
     -viii. Send the label mapping message with the new forward label
            and the FEC to the next hop S-PE/T-PE.

   For the reverse direction:
        -i. Install the received FEC for the reverse direction.
       -ii. Determine the next signaling hop by referencing the LDP
            sessions used to setup the LSP in the Forward direction.
      -iii. Allocate a new PW label for the reverse direction.
       -iv. Install the FEC for the reverse direction.
        -v. Send the label mapping message with a new label and the FEC
            to the next hop S-PE/ST-PE.

7.2.4. Support for Explicit PW Path

   The Explicit Route TLV format defined in [RFC3212] section 4.1 MAY be
   used to signal an explicit path for a MS-PW. An Explicit PW path may
   be required to provide a simple solution for 1:1 protection with
   diverse primary and backup path or to enable controlled signaling
   (strict or loose) for special PWs. Details of its usage to be
   provided in a future version.

8. Failure Handling Procedures

8.1. PSN Failures

   Failures of the PSN tunnel MUST be handled by PSN mechanisms. If the
   PSN is unable to re-establish the PSN tunnel, then the S-PE SHOULD
   follow the procedures defined in Section 8 of [PW-SEG].

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8.2. S-PE Failures

   For defects in an S-PE, the procedures defined in [PW-SEG] SHOULD be
   followed.  However the ST-PE MAY re-signal the PW if an alternate
   path is available.

9. Operations and Maintenance (OAM)

   The OAM procedures defined in [PW-SEG] may be used also for MS-PWs. A
   PW switching point TLV is used [PW-SEG] to record the switching
   points that the PW traverses.

   In the case of a MS-PW where the PW Endpoints are identified though
   using a globally unique, FEC 129-based AII addresses, there is no
   PWID defined on a per segment basis. Each individual PW segment is
   identified by the address of adjacent S-PE(s) in conjunction with the
   SAII and TAII. In this case, the following type MUST be used in place
   of type 0x01 in the PW switching point TLV:

   Type      Length    Description
   0x04        8       Global ID/Prefix of the S-PE

   The above field MUST be included together with type 0x02 in the TLV
   once per individual PW Switching Point following the same rules and
   procedures as described in [PW-SEG].

10. Security Considerations

   This document specifies only extensions to the protocols already
   defined in [RFC4447], and [PW-SEG]. Each such protocol may have its
   own set of security issues, but those issues are not affected by the
   extensions specified herein. Note that the protocols for dynamically
   distributing PW Layer 2 reachability information may have their own
   security issues, however those protocols specifications are outside
   the scope of this document.

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11. IANA Considerations

   This document uses several new LDP TLV types, IANA already maintains
   a registry of name "TLV TYPE NAME SPACE" defined by RFC3036. The
   following value is suggested for assignment:

      TLV type  Description
       0x096E   Bandwidth TLV

11.1. LDP Status Codes

   This document uses several new LDP status codes, IANA already
   maintains a registry of name "STATUS CODE NAME SPACE" defined by
   RFC3036. The following value are suggested for assignment:

   Range/Value     E     Description                       Reference
   ------------- -----   ----------------------            ---------
        TBD        0     Bandwidth resources unavailable   RFCxxxx
        TBD        0     Resources Unavailable             RFCxxxx
        TBD        0     AII Unreachable                   RFCxxxx

11.2. BGP SAFI

   IANA needs to allocate a new BGP SAFI for "Psedo Wire routing
   information" from the L2VPN SAFI registry.

12. Full Copyright Statement

   Copyright (C) The Internet Society (2006).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

   This document and the information contained herein are provided on an

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13. Intellectual Property Statement

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at ietf-

14. Normative References

   [PW-SEG] Martini et.al. "Segmented Pseudo Wire",
        draft-ietf-pwe3-segmented-pw-00.txt, IETF Work in Progress,
        July 2005

   [TSPEC] Wroclawski, J. "The Use of RSVP with IETF Integrated
        Services", RFC 2210, September 1997

   [RFC3036bis] Andersson, Minei, Thomas. "LDP Specification"
        draft-ietf-mpls-rfc3036bis-03.txt, IETF Work in Progress,
        October 2005

   [RFC4447] "Transport of Layer 2 Frames Over MPLS", Martini L.,et al
        draft-ietf-pwe3-control-protocol-17.txt, ( work in progress ),
        June 2005.

   [AII] "Pseudowire Attachment Identifiers for Aggregation and
         VPN Autodiscovery", Chris M., et al
        draft-metz-aii-aggregate-01.txt, October 2006 (work in progress)
        February, 2006

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   [RFC3212] B. Jamoussi, et al. "Constraint-Based LSP Setup using LDP",
        RFC3212, January 2002.

15. Informative References

   [MS-REQ] Martini et al, "Requirements for Inter-domain Pseudo-Wires",
        draft-ietf-pwe3-ms-pw-requirements-02, Martini, et al.,
        June 2006

   [MS-ARCH] Bocci at al, "Architecture for Multi-Segment PWE3",
        draft-bocci-bryant-pwe3-ms-pw-arch-01.txt, September 2005.
        ( work in progress )

   [L2VPN-SIG] E. Rosen, et Al. "Provisioning, Autodiscovery,
        and Signaling in L2VPNs", draft-ietf-l2vpn-signaling-06.txt,
        September 2005 ( work in progress )

   [RFC2858] Bates, T., Rekhter, Y., Chandra, R. and D. Katz,
        "Multiprotocol Extensions for BGP-4", RFC 2858, June 2000.

16. Author Information

   Luca Martini
   Cisco Systems, Inc.
   9155 East Nichols Avenue, Suite 400
   Englewood, CO, 80112
   e-mail: lmartini@cisco.com

   Matthew Bocci
   Alcatel Telecom Ltd,
   Voyager Place
   Shoppenhangers Road
   Berks, UK
   e-mail: matthew.bocci@alcatel.co.uk

   Florin Balus
   3500 Carling Ave.
   Ottawa, Ontario, CANADA
   e-mail: balus@nortel.com

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Internet Draft    draft-ietf-pwe3-dynamic-ms-pw-01.txt         June 2006

   Nabil Bitar
   40 Sylvan Road
   Waltham, MA 02145
   e-mail: nabil.bitar@verizon.com

   Himanshu Shah
   Ciena Corp
   35 Nagog Park,
   Acton, MA 01720
   e-mail: hshah@ciena.com

   Mustapha Aissaoui
   600 March Road
   ON, Canada
   e-mail: mustapha.aissaoui@alcatel.com

   Jason Rusmisel
   600 March Road
   ON, Canada
   e-mail: Jason.rusmisel@alcatel.com

   Yetik Serbest
   SBC Labs
   9505 Arboretum Blvd.
   Austin, TX 78759
   e-mail: Yetik_serbest@labs.sbc.com

   Andrew G. Malis
   Tellabs, Inc.
   2730 Orchard Parkway
   San Jose, CA, USA 95134
   e-mail: Andy.Malis@tellabs.com

Martini, et al.                                                [Page 18]

Internet Draft    draft-ietf-pwe3-dynamic-ms-pw-01.txt         June 2006

   Chris Metz
   Cisco Systems, Inc.
   3700 Cisco Way
   San Jose, Ca. 95134
   e-mail: chmetz@cisco.com

   David McDysan
   22001 Loudoun County Pkwy
   Ashburn, VA, USA 20147
   e-mail: dave.mcdysan@mci.com

   Jeff Sugimoto
   3500 Carling Ave.
   Ottawa, Ontario, CANADA
   e-mail: sugimoto@nortel.com

   Mike Duckett
   Lindbergh Center D481
   575 Morosgo Dr
   Atlanta, GA  30324
   e-mail: mduckett@bellsouth.net

   Mike Loomis
   600, Technology Park Dr
   Billerica, MA, USA
   e-mail: mloomis@nortel.com

   Paul Doolan
   Mangrove Systems
   IO Fairfield Blvd
   Wallingford, CT, USA 06492
   e-mail: pdoolan@mangrovesystems.com

Martini, et al.                                                [Page 19]

Internet Draft    draft-ietf-pwe3-dynamic-ms-pw-01.txt         June 2006

   Ping Pan
   Hammerhead Systems
   640 Clyde Court
   Mountain View, CA, USA 94043
   e-mail: ppan@hammerheadsystems.com

   Prayson Pate
   Overture Networks, Inc.
   507 Airport Blvd, Suite 111
   Morrisville, NC, USA 27560
   e-mail: prayson.pate@overturenetworks.com

   Vasile Radoaca

   Yuichiro Wada
   NTT Communications
   3-20-2 Nishi-Shinjuku, Shinjuke-ku
   Tokyo 163-1421, Japan
   e-mail: yuichiro.wada@ntt.com

   Yeongil Seo
   Korea Telecom Corp.
   463-1 Jeonmin-dong, Yusung-gu
   Daejeon, Korea
   e-mail: syi1@kt.co.kr

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