CCAMP Working Group                                  G. Bernstein (ed.)
Internet Draft                                        Grotto Networking
Updates: RFC 3946                                           D. Caviglia
Category: Standards Track                                      Ericsson
Expires: April September 2007                                       R. Rabbat (ed.)
                                                                Fujitsu
                                                                 Google
                                                        H. van Helvoort
                                                                 Huawei
                                                       October 20, 2006
                                                         March 30, 2007

       Operating Virtual Concatenation (VCAT) and the Link Capacity
      Adjustment Scheme (LCAS) with Generalized Multi-Protocol Label
                             Switching (GMPLS)
                  draft-ietf-ccamp-gmpls-vcat-lcas-01.txt
                  draft-ietf-ccamp-gmpls-vcat-lcas-02.txt

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Abstract

   This document describes requirements for, and use of, the Generalized
   Multi-Protocol Label Switching (GMPLS) control plane in conjunction
   with the Virtual Concatenation (VCAT) layer 1 inverse multiplexing
   mechanism and its companion Link Capacity Adjustment Scheme (LCAS)
   which can be used for hitless dynamic resizing of the inverse
   multiplex group.  These techniques apply to the Optical Transport
   Network (OTN), Synchronous Optical Network (SONET), Synchronous
   Digital Hierarchy (SDH), and Plesiochronous Digital Hierarchy (PDH)
   signals.

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 RFC-2119 [RFC2119].

Table of Contents

   1. Introduction...................................................3
   2. Revision History...............................................3
      2.1. Changes from draft-ieft-ccamp-gmpls-vcat-lcas-01..........3
      2.2. Changes from draft-bernstein-ccamp-gmpls-vcat-lcas-03..........3 draft-ietf-ccamp-gmpls-vcat-lcas-00..........4
   3. VCAT/LCAS Scenarios and Specific Requirements..................3 Requirements..................4
      3.1. Multiple VCAT Groups per GMPLS Endpoint...................3 VCAT/LCAS Interface Capabilities..........................4
      3.2. Component Member Signal Configuration Requirements...............3 Scenarios.....................4
      3.3. VCAT Operation With or Without LCAS.......................4 LCAS.......................5
   4. GMPLS Mechanisms for Signaling VCAT/LCAS.......................4 in Support of VCGs............................6
      4.1. Co-Routed Signals.........................................5 VCGs Composed of a Single Co-Signaled Member Set..........7
         4.1.1. One-shot VCG Setup of Co-Routed Signal...................5 with Co-Signaled Members..........7
         4.1.2. Incremental VCG Setup of Co-Routed Signal................5 with Co-Signaled Members.......7
         4.1.3. Procedure for VCG Reduction by Removing a Component Signal..........................6 Member.....8
         4.1.4. Removing Multiple Component Signals VCG Members in One Shot......6 Shot............8
         4.1.5. Use of multiple LSPs for Co-Routed Signals...........7
         4.1.6. Teardown of Whole VCG................................7 VCG................................9
      4.2. Diversely Routed Signals..................................7 VCGs Composed of Multiple Co-Signaled Member Sets.........9
         4.2.1. Associating Diversely Routed Signals.................7
         4.2.2. Procedures for Signaled VCG Setup Using Diversely Routed
         Components..................................................8
         4.2.3. Layer Information.......................9
         4.2.2. Procedures for VCG Reduction/Teardown Using Diversely
         Routed Components...........................................9
         4.2.4. Update of Already Established LSPs...................9
         4.2.5. One LSP Control with Multiple Co-signaled
         Member Sets................................................10
      4.3. Member Sharing -- Multiple VCGs per Circuit..................................9 Call.................11
   5. IANA Considerations...........................................10 Considerations...........................................12
   6. Security Considerations.......................................10 Considerations.......................................12
   7. Contributors..................................................11 Contributors..................................................13
   8. Acknowledgments...............................................11 Acknowledgments...............................................13
   9. References....................................................12 References....................................................14
      9.1. Normative References.....................................12 References.....................................14
      9.2. Informative References...................................12 References...................................14
   Author's Addresses...............................................13 Addresses...............................................15
   Intellectual Property Statement..................................14 Statement..................................15
   Disclaimer of Validity...........................................14 Validity...........................................16
   Copyright Statement..............................................14
   Acknowledgment...................................................15 Statement..............................................16
   Acknowledgment...................................................16

1. Introduction

   The Generalized Multi-Protocol Label Switching (GMPLS) suite of
   protocols allows the automated control of different switching
   technologies including SONET/SDH. SONET/SDH and OTN. This document describes
   extensions to RSVP-TE to support the Virtual Concatenation (VCAT)
   layer 1 inverse multiplexing mechanism that has been standardized for
   SONET, SDH, OTN and PDH technologies along with its companion Link
   Capacity Adjustment Scheme (LCAS).  These

   VCAT is a TDM oriented byte striping inverse multiplexing method that
   works with a wide range of existing and emerging TDM framed signals,
   including very high bit rate OTN and SDH/SONET signals. Other than
   member signal skew compensation layer 1 inverse multiplexing
   mechanism add minimal additional signal delay. VCAT permits the
   selection of an optimal signals size, extracting bandwidth from mesh
   networks and when combined with LCAS hitless dynamic resizing of
   bandwidth and fast graceful degradation in the presence of network
   faults. To take full advantage of VCAT/LCAS functionality extensions
   to GMPLS signaling are given that enable the setup of diversely
   routed circuits that are members of the same VCAT group.

2. Revision History

2.1. Changes from draft-ieft-ccamp-gmpls-vcat-lcas-01

   o  Changed section 3.1 from "Multiple VCAT Groups per GMPLS endpoint"
      to "Multiple VCAT Groups per Interface" to improve clarity.

   o  Changed terminology from "component" signal to "member" signal
      where possible (not quoted text) to avoid confusion with link
      bundle components.

   o  Added "Dynamic, member sharing" scenario.

   o  Clarified requirements with respect to scenarios and the LCAS and
      non-LCAS cases.

   o  Added text describing needed signaling information between the
      VCAT endpoints to support required scenarios.

   o  Added text to describe: co-signaled, co-routed, data plane LSP,
      control plane LSP and their relationship to the VCAT/LCAS
      application.

   o  Change implementation mechanism from one based on the Association
      object to one based on "Call concepts" utilizing the Notify
      message.

2.2. Changes from draft-ietf-ccamp-gmpls-vcat-lcas-00

   o  Updated reference from RFC3946bis to issued RFC4606

   o  Updated section 3.2 based on discussions on the mailing list

3. VCAT/LCAS Scenarios and Specific Requirements

   There are a number of specific requirements for the support of
   VCAT/LCAS in GMPLS that can be derived from the carriers'
   application-specific demands for the use of VCAT/LCAS and from the
   flexible nature of VCAT/LCAS.  These are set out in the following
   section.

3.1. Multiple VCAT Groups per GMPLS Endpoint VCAT/LCAS Interface Capabilities

   In general, an LSR can be ingress/egress of one or more VCAT groups.
   VCAT and LCAS are interface capabilities.  An LSR may have, for
   example, VCAT-capable interfaces that are not LCAS-capable.  It may
   at the same time have interfaces that are neither VCAT nor LCAS-
   capable.

3.2. Component Member Signal Configuration Requirements Scenarios

   We list in this section the different scenarios that SHOULD be
   supported. scenarios.  Here we use the
   term "VCG" to refer to the entire VCAT group and the terminology
   "set" and "subset" to refer to the collection of potential VCAT group
   member signals.

   Note that LCAS-capable interfaces can support all scenarios with no
   loss of traffic.

   o  Fixed, co-routed: A fixed bandwidth VCG, transported over a co-
      routed set of member signals.  This is the case where the intended
      bandwidth of the VCG does not change and all member signals follow
      the same route and minimize differential delay.  The intent here
      is the capability to allocate an amount of bandwidth close to that
      required at the client layer.

   o  Fixed, diversely routed: A fixed bandwidth VCG, transported over
      at least two diversely routed subsets of member signals.  In this
      case, the subsets are link-disjoint over at least one link of the
      route.  The intent here is more efficient use of network resources
      (no unique route has the required bandwidth).

   o  Fixed, member sharing: A fixed bandwidth VCG, transported over a
      set of member signals that are allocated from a common pool of
      available member signals without requiring member connection
      teardown and setup.

   o  Dynamic, co-routed: A dynamic VCG (bandwidth can be increased or
      decreased via the addition or removal of member signals),
      transported over a co-routed set of members.  The intent here is
      dynamic resizing and resilience of bandwidth.

   o  Dynamic, diversely routed: A dynamic VCG (bandwidth can be
      increased or decreased via the addition or removal of member
      signals), transported over at least two diversely routed subsets
      of member signals.  The intent here is efficient use of network
      resources, dynamic resizing and resilience of bandwidth.

3.3. VCAT Operation With

   o  Dynamic, member sharing: A dynamic bandwidth VCG, transported over
      a set of member signals that are allocated from a common pool of
      available member signals without requiring member connection
      teardown and setup.

3.3. VCAT Operation With or Without LCAS

   VCAT capabilities may be present with or without the presence of
   LCAS.  The use of LCAS is beneficial to the provision of services,
   but in the absence of LCAS, VCAT is still a valid technique.
   Therefore GMPLS mechanisms for the operation of VCAT are REQUIRED for
   both the case where LCAS is available and the case where it is not
   available.  The GMPLS procedures for the two cases SHOULD be
   identical.

   o  GMPLS signaling for LCAS-capable interfaces MUST support all
      scenarios of section 3.2. with no loss of traffic.

   o  GMPLS signaling for non-LCAS-capable interfaces MUST support only
      the "fixed" scenarios of section 3.2.

   To provide for these requirements GMPLS signaling MUST carry the
   following information on behalf of the VCAT endpoints:

   o  The type of the member signal that the VCG will contain, e.g., VC-
      3, VC-4, etc.

   o  The total number of member to be in the VCG. This provides the
      endpoints in both the LCAS and non-LCAS case with information on
      which to accept or reject the request, and in the non-LCAS case
      will let the receiving endpoint know when all members of the VCG
      have been established.

   o  Identification of the VCG and its associated members. This
      provides information that allows the endpoints to differentiate
      multiple VCGs and to tell what members (LSPs) to associate with a
      particular VCG.

4. GMPLS Mechanisms for Signaling VCAT/LCAS in Support of VCGs

   We describe in this section the signaling mechanisms that already
   exist in GMPLS using RSVP-TE [RFC3473] and the extensions needed, for
   diversely routed paths and in support of the LCAS procedure.

   Section 4.1 is included for informational purposes only.  It
   describes existing procedures and makes no changes.

   Section 4.2 describes new procedures needed to
   completely support diversely routed VCAT
   groups.  Where possible it reuses applicable existing procedures from the requirements of section 4.1.

4.1. Co-Routed Signals

   Note 3.

   When utilizing GMPLS with VCAT/LCAS we utilize a number of control
   and data plane concepts that this section we describe below.

  1. VCG member -- This is for informational purposes only.

   The existing signaling protocols support co-routed an individual data plane signal setup using
   the NVC field as explained in section 2.1 of [RFC4606].  In this
   case, one single LSP is set up in of the
     permitted SDH, SONET, OTN or PDH signal types.

  2. Co-signaled member set -- One or more VCG members (or potential
     members) set up via the same control plane signaling exchange. Note
     that all members in a co-signaled set follow the same route.

  3. Co-routed member set - One or more VCG members that follow the same
     route. Although VCG members may follow the same path, this does not
     imply that they we co-signaled.

  4. Data plane LSP -- for our purposes here this is equivalent to an
     individual VCG member.

  5. Control plane LSP -- A control plane entity that can control
     multiple data plane LSPs. For our purposes here this is equivalent
     to our co-signaled member set.

   Section 4.1 is included for informational purposes only.  It
   describes existing GMPLS procedures that support a single VCG
   composed of a single co-signaled member set.

   Section 4.2 describes new procedures to support VCGs composed of more
   that one co-signaled member sets. This includes the important
   application of a VCG composed of diversely routed members.  Where
   possible it reuses applicable existing procedures from section 4.1.

4.1. VCGs Composed of a Single Co-Signaled Member Set

   Note that this section is for informational purposes only.

   The existing signaling GMPLS signaling protocols support a VCG
   composed of a single co-signaled member set. Setup using the VCAT group. NVC
   field as explained in section 2.1 of [RFC4606].  In this case, one
   single control plane LSP is used in support of the VCG.

   There are two options for setting up the VCAT group, VCG, depending on hardware
   capability, or management preferences: one-shot setup and incremental
   setup.

   The following sections explain the procedure based on an example of
   setting up a VC-4-7v SDH VCAT group (corresponding to an STS-3c-7v
   SONET VCAT group).

4.1.1. One-shot VCG Setup of Co-Routed Signal with Co-Signaled Members

   An RSVP-TE Path message is used with the following parameters.

   With regards to the traffic parameters, the elementary signal is
   chosen (6 for VC-4/STS-3c_SPE).  The value of NVC is then set to 7.

   A Multiplier Transform greater than 1 (say N>1) is used if the
   operator wants to set up N VCAT groups that will belong to, and be
   assigned to, one LSP.

   SDH or SONET labels in turn have to be assigned for each member of
   the VCG and concatenated to form a single Generalized Label
   constructed as an ordered list of 32-bit timeslot identifiers of the
   same format as TDM labels.  [RFC4606] requires that the order of the
   labels reflect the order of the payloads to concatenate, and not the
   physical order of time-slots.

4.1.2. Incremental VCG Setup of Co-Routed Signal with Co-Signaled Members

   In some cases, it may be necessary or desirable to set up the VCG
   members individually, or to add group members to an existing group.

   One example of this need is when the hardware that supports VCAT can
   only add VCAT elements one at a time or cannot automatically match
   the elements at the ingress and egress for the purposes of inverse
   multiplexing.  Serial or incremental setup solves this problem.

   In order to accomplish incremental setup an iterative process is used
   to add group members.  For each iteration, NVC is incremented up to
   the final value required.  The iteration consists of the successful
   completion of Path and Resv signaling.  At first, NVC = 1 and the
   label includes just one timeslot identifier

   At each of the next iterations, NVC is set to (NVC +1), one more
   timeslot identifier is added to the ordered list in the Generalized
   Label (in the Path or Resv message).  A node that receives a Path
   message that contains changed fields will process the full Path
   message and, based on the new value of NVC, it will add a component
   signal to the VCAT group, and switch the new timeslot based on the
   new label information.

   Following the addition of the new label to the LSP, LCAS may be used
   in-band to add the new label into the existing VCAT group.  LCAS
   signaling for this function is described in [ITU-T-G.7042].

4.1.3. Procedure for VCG Reduction by Removing a Component Signal Member

   A VCG member can be permanently removed from the VCG either as the
   result of a management command or following a temporary removal (due
   to a failure).

   The procedure to remove a component signal is similar to that used to
   add components as described in Section 4.1.2.  The LCAS in-band
   signaling step is taken first to take the component out of service
   from the group.  LCAS signaling is described in [ITU-T-G.7042].

   In this case, the NVC value is decremented by 1 and the timeslot
   identifier for the dropped component is removed from the ordered list
   in the Generalized Label.

   Note that for interfaces that are not LCAS-capable, removing one
   component of the VCG will result in errors in the inverse-
   multiplexing procedure of VCAT and result in the teardown of the
   whole group.  So, this is a feature that only LCAS-capable VCAT
   interfaces can support without management intervention at the end
   points.

4.1.4. Removing Multiple Component Signals VCG Members in One Shot

   The procedure is similar to 4.1.3.  In this case, the NVC value is
   changed to the new value and all relevant timeslot identifiers for
   the components to be torn down are removed from the ordered list in
   the Generalized Label.  This procedure is also not supported for
   VCAT-only interfaces without management intervention as removing one
   or more components of the VCG will tear down the whole group.

4.1.5. Use of multiple LSPs for Co-Routed Signals

   Co-routed signals may also be supported by distinct LSPs signaled
   separately using exactly the techniques described for diversely
   routed signals in Section 4.2.

4.1.6. Teardown of Whole VCG

   The entire LSP is deleted in a single step (i.e., all components are
   removed in one go) using deletion procedures of [RFC3473].

4.2. Diversely Routed Signals VCGs Composed of Multiple Co-Signaled Member Sets

   The motivation for VCGs composed of multiple co-signaled member sets
   comes from the requirement to support VCGs with diversely routed
   members. The initial GMPLS specification did not support diversely
   routed signals using the NVC construct.  In fact, [RFC4606] says:

         [...] The standard definition for virtual concatenation allows
         each virtual concatenation components to travel over diverse
         paths.  Within GMPLS, virtual concatenation components must
         travel over the same (component) link if they are part of the
         same LSP.  This is due to the way that labels are bound to a
         (component) link.  Note however, that the routing of components
         on different paths is indeed equivalent to establishing
         different LSPs, each one having its own route.  Several LSPs
         can be initiated and terminated between the same nodes and
         their corresponding components can then be associated together
         (i.e., virtually concatenated).

   Diverse routing

   The setup of signals can be diversely routed VCG members requires multiple co-
   signaled VCG member sets, i.e., multiple control plane LSPs.

   To support a useful capability but VCG with multiple co-signaled VCG members sets requires
   being able to identify separate control plane LSPs with a single VCG
   and exchange information pertaining to the extensions identified VCG as a whole. This is
   very similar to the "Call" concept described in this document.

4.2.1. Associating Diversely Routed Signals

   The feature [CallDraft]. We can
   think of our VCAT/LCAS connection, e.g., our VCG, as a higher layer
   service that needs to be added makes use of multiple lower layer (server) connections
   that are controlled by one or more control plane LSPs.

4.2.1. Signaled VCG Layer Information

   When a VCG is composed of multiple co-signaled member sets, none of
   the functionality control plane LSP's signaling information can contain information
   pertinent to associate the components of the same entire VCG.  For In this purpose, section we use the
   Association Object that was defined in [E2E-RECOVERY] to associate
   working and recovery LSPs.

   A diversely routed VCG uses give a number list of routes R <= VCG size,
   information that should be communicated at what we define as some
   routes may the VCG
   Call layer, i.e., between the VCG signaling endpoints.  To
   accommodate this information additional objects or TLVs would need to
   be incorporated into the same Notify message as it is described for several components.  A number of LSPs, L
   (VCG >= L >= R) are used use in
   call signaling in [CallDraft].

   VCG Call setup information signaled via the Notify message with each LSP establishing at least one
   component of the VCG, and at most all
   Call management bit (C-bit) set:

     1. Signal Type

     2. Number of the co-routed members VCG Members

     3. LCAS requirements:

          a.  LCAS required

          b. LCAS desired

          c. LCAS not desired (but acceptable)

          d. LCAS not acceptable

     4. Maximum Number of the
   group.  For VCGs per Call-- This is a set of c components using hook to support the same route, we set up
        member sharing scenario. In the
   LSP non-member sharing case the
        value is one.

4.2.2. Procedures for VCG Control with NVC = c exactly as explained in Multiple Co-signaled Member Sets

   This section 4.1.1.  Therefore, deals only with the association of group members or case of sub-groups to form the one VCG
   requires per (VCG) Call. To
   establish a VCG, the association information of section 4.2.1. is exchanged and
   agreed upon with the corresponding VCG signaling endpoint. Since only
   one VCG is being signaled by this call, all control plane LSPs used to
   with this call establish members for this VCG and there is no
   ambiguity as to which VCG a potential member belongs. Procedures for
   addition and removal of bandwidth are the group same as the single co-
   signaled case except that a VCG Call layer message should precede any
   of those changes and indicate the new total number of VCG members.

   To be able

   In general the following order is used to distinguish establish and increase the LSPs
   bandwidth in the a VCG:

     1. VCG each must have Call layer information is conveyed. Note that during a unique
   identifier.
        "bandwidth" change only the total number of VCG members is
        allowed to change.

     2. Control Plane LSPs are identified used to add data plane LSPs (members) to
        the VCG.

     3. If LCAS is supported on this VCG call it should be instructed by
        the combination of Session and
   Sender Template fields.  It endpoints to "activate" the member.

   In general the following order is common practice used when make-before-break
   [RFC3209] decreasing the bandwidth
   in a VCG:

     1. VCG Call layer information is supported to allow LSPs with conveyed concerning the same Session, but
   different Sender Templates (specifically with different LSP IDs) to
   share resources.  Since resource sharing between decreased
        number of VCG members.

     2. If LCAS is supported on this VCG members must not call it should be allowed (because we want each LSP to contribute capacity to instructed by
        the
   VCG), but since we want endpoints to continue "deactivate" the members to support make-before-break for
   each group member, it is necessary be removed.

     3. Existing control plane LSPs are used to distinguish remove the data plane
        LSPs in the VCG
   by varying the fields in the Session object.  Specifically, a
   different Tunnel ID (members).

   Note that when LCAS is not used to identify each LSP in or unavailable the VCG.

   Thus, VCG members cannot will be associated through in an
   unknown state between the Session object,
   and time the Association object VCG call level information is used instead.

   The assignment of
   updated and the Association ID is outside actual data plane LSPs are added or removed.

4.3. Member Sharing -- Multiple VCGs per Call

   To support the scope member sharing scenario of GMPLS
   but MUST be unique for each VCAT group.

   Note that section 3.2. we allow
   multiple VCGs within the use context of the Association object VCG Call defined here. This
   is partially due to associate members of the requirement in reference [CallDraft] that
   LSPs are associated with a single call over their lifetime. Hence we
   propose using the VCG does not preclude Call mechanism previously described to
   establish the use of another instance of common member pool for all the object with
   a different Association ID VCGs to indicate be included in
   the association scope of working and
   recovery LSPs, as [E2E-RECOVERY] allows this particular VCG Call. Note that the use maximum number
   of multiple
   Association objects.  We differentiate between the Association
   objects used for the VCGs per call is a key parameter to call acceptance or rejection
   since VCAT group and other Association objects through equipment typically puts limits on the definition total number of
   VCGs that can be simultaneously supported.

   To assign a new association type data plane LSP to indicate that this is be a member of a particular VCG association.

   Association Type: 16 bits

               Value       Type
               -----       ----

                 3         VCAT group

   See [E2E-RECOVERY] for the definition or to
   remove a data plane LSP from being a member of other fields and values a particular VCG,
   requires additional VCG layer communications. LCAS [ITU-T-G.7042]
   cannot provide such signaling since it does not to provide a way to
   indicate which VCG out of
   the Association object.

4.2.2. Procedures multiple between a source and destination a
   member should belong. In particular, although, it seems that LCAS'
   Group Identification (GID) bit should be useful for VCG Setup Using Diversely Routed Components

   For every route R, use the procedure outlined in section 4.1.1 or
   4.1.2 depending on this purpose
   reference [ITU-T-G.7042] specifically states:

          "The GID provides the capability receiver with a means of
          verifying that all the equipment or local policy. arriving members originated
          from one transmitter. The Path message MUST include contents are pseudo-
          random, but the Association object with type set receiver is not required to
   3, and each Path message MUST use
          synchronize with the same Association ID.

   Following incoming stream."
   In the addition following we sketch the outline of such a high level VCG layer
   signaling procedure that could make use of each new LSP (i.e., once the RESV Notify message as in
   reference [CallDraft].

   After the VCG call has been received by the ingress LSR), LCAS established, a signaling is used in-band
   to hitlessly add the new label into endpoint of the existing group [ITU-T-
   G.7042].

4.2.3. Procedures
   VCG call for would then:

     1. Choose an identifier for each VCG Reduction/Teardown Using Diversely Routed
   Components

   To remove that will use member signals
        from the component circuits on any route, LCAS in-band signaling
   is used common pool. Note that these identifiers only need to remove the labels associated
        be unique with in the LSP from context of the group.
   LCAS signaling is defined in [ITU-T-G.7042].

   In addition, VCG Call.

     2. Assign member signals from the procedures outlined in section 4.1.3 or 4.1.4 are
   used common pool to tear down the unwanted LSP.

   Again, this can only be done on LCAS-capable interfaces.  If each of the
   procedure is attempted on VCAT-only interfaces, then VCG
        utilizing the whole previously defined VCG is
   torn down (this is not a graceful teardown IDs.  Member signals are
        identified by their tunnel id, LSP id, and label ordinal (labels
        for control plane LSPs with multiple members are strictly
        ordered so ingress/egress initiate we can specify an individual signal from its label
        order). Similarly for removing a Path Tear/Resv Tear) on all routes.

4.2.4. Update of Already Established LSPs

   Established co-routed VCAT groups currently do not support the
   Association object.  If member signal from a co-routed VCAT Group size is VCG and
        returning it to be
   increased with new diversely routed members, we use the LSP
   modification procedure described common pool.

     3. Coordinate with LCAS in [RFC2205].  An Association object that a member signal is first added to a
        VCG from the Path message for pool before LCAS is notified to "activate" that
        signal in the existing LSP(s).  That
   Association object can then be used VCG. Similarly LCAS is notified to set up new diversely routed
   group members.

   The same applies "deactivate" a
        member signal prior to SONET/SDH LSPs.  An operator may decide removing it from the VCG and returning it
        to use an
   already cross-connected SONET/SDH LSP for diversely-routed VCAT.  In
   this case the modification procedure described in [RFC2205] is used
   as well.

4.2.5. One pool.

     4. Note that before any LSPs or members of an LSP per Circuit

   These procedures can support be removed
        from the use (overall) VCG Call, the originator must ensure that
        signals have been removed from any of as many LSPs as there are
   circuits in the VCG. VCGs. This can be done when each circuit is
   separately routed, or when some of the circuits are co-routed,
        situation where the entire pool size is lowered.

   The exact objects and
   each LSP will be used formats to set up one element of carry this information is to be
   determined. Once again the VCG.  The
   Association object Notify mechanism would be appropriate
   since this is used information to indicate be transferred between the VCG association. Call
   endpoints and is not relevant to the intermediate switches.

5. IANA Considerations

   This document requests from IANA the assignment of a new Association
   Type within the Association object.  This object was defined in [E2E-
   RECOVERY].

   The value 3 "VCAT group" is suggested in section 4.2.1. ... (Don't know
   yet what we may want)

6. Security Considerations

   This document introduces a new specific use of the Association Notify message and
   admin status object for GMPLS signaling [RFC3473] to associate diversely routed VCAT group
   members. as originally specified in
   [CallDraft].  It does not introduce any new signaling messages, nor
   change the relationship between LSRs that are adjacent in the control
   plane.  This association  The call information associated with diversely routed control
   plane LSPs, in the event of an interception may indicate that there
   are members of the same VCAT group that take a different route and
   may indicate to an interceptor that the network
   may be more robust. VCG call desires increased
   reliability.

   Otherwise, this document does not introduce any additional security
   considerations.

7. Contributors

   Wataru Imajuku (NTT)
   1-1 Hikari-no-oka Yokosuka Kanagawa 239-0847
   Japan

   Phone +81-46-859-4315
   Email: imajuku.wataru@lab.ntt.co.jp

   Julien Meuric
   France Telecom
   2, avenue Pierre Marzin
   22307 Lannion Cedex
   France

   Phone: + 33 2 96 05 28 28
   Email: julien.meuric@orange-ft.com

   Lyndon Ong
   Ciena
   PO Box 308
   Cupertino, CA 95015
   United States of America

   Phone: +1 408 705 2978
   Email: lyong@ciena.com

8. Acknowledgments

   The authors would like to thank Adrian Farrel, Maarten Vissers,
   Trevor Wilson Wilson, Evelyne Roch, Vijay Pandian, Fred Gruman, Dan Li,
   Stephen Shew, Jonathan Saddler and
   Adrian Farrel Dieter Beller for extensive
   reviews and contributions to this draft.

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.

   [RFC2205]      Braden, R., Zhang, L., Berson, S., Herzog, S. and S.
                  Jamin, "Resource ReSerVation Protocol (RSVP) --
                  Version 1, Functional Specification", RFC 2205,
                  September 1997.

   [RFC3209]      Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan,
                  V., and G. Swallow, "RSVP-TE: Extensions to RSVP for
                  LSP Tunnels", RFC 3209, December 2001.

    [RFC3473]     Berger, L., "Generalized Multi-Protocol Label
                  Switching (GMPLS) Signaling Resource ReserVation
                  Protocol-Traffic Engineering (RSVP-TE) Extensions",
                  RFC 3473, January 2003.

   [RFC4606]      Mannie, E. and D. Papadimitriou, "Generalized Multi-
                  Protocol Label Switching (GMPLS) Extensions for
                  Synchronous Optical Network (SONET) and Synchronous
                  Digital Hierarchy (SDH) Control", RFC 4606, December
                  2005.

   [E2E-RECOVERY] Lang, J.P., Rekhter, Y., and

   [CallDraft]    D. Papadimitriou (eds.),
                  "RSVP-TE and A. Farrel, "Generalized MPLS
                  (GMPLS) RSVP-TE Signaling Extensions in support of End-to-End
                  Generalized Multi-Protocol Label Switching (GMPLS)-
                  based Recovery", IETF draft, work in progress, April
                  2005.
                  Calls", draft-ietf-ccamp-gmpls-rsvp-te-call-04.txt,
                  January, 2007.

9.2. Informative References

   [ANSI-T1.105]  American National Standards Institute, "Synchronous
                  Optical Network (SONET) - Basic Description including
                  Multiplex Structure, Rates, and Formats", ANSI T1.105-
                  2001, May 2001.

   [ITU-T-G.7042] International Telecommunications Union, "Link Capacity
                  Adjustment Scheme (LCAS) for Virtual Concatenated
                  Signals", ITU-T Recommendation G.7042, March 2006.

   [ITU-T-G.7043] International Telecommunications Union, "Virtual
                  Concatenation of Plesiochronous Digital Hierarchy
                  (PDH) Signals", ITU-T Recommendation G.7043, July
                  2004.

   [ITU-T-G.707]  International Telecommunications Union, "Network Node
                  Interface for the Synchronous Digital Hierarchy
                  (SDH)", ITU-T Recommendation G.707, December 2003.

   [ITU-T-G.709]  International Telecommunications Union, "Interfaces
                  for the Optical Transport Network (OTN)", ITU-T
                  Recommendation G.709, March 2003.

Author's Addresses

   Greg Bernstein
   Grotto Networking

   Phone: +1-510-573-2237
   Email: gregb@grotto-networking.com

   Diego Caviglia
   Ericsson
   Via A. Negrone 1/A 16153
   Genoa Italy

   Phone: +39 010 600 3736
   Email: diego.caviglia@(marconi.com, ericsson.com)

   Richard Rabbat
   Fujitsu Laboratories of America
   1240 East Arques Ave, MS 345
   Sunnyvale, CA 94085
   United States of America

   Phone: +1 408-530-4537
   Google

   Email: richard@us.fujitsu.com richard.rabbat@gmail.com

   Huub van Helvoort
   Huawei Technologies, Ltd.
   Kolkgriend 38, 1356 BC Almere
   The Netherlands

   Phone:   +31 36 5315076
   Email:   hhelvoort@huawei.com

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