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   Network Working Group                          Dimitri Papadimitriou
   Internet Draft                                      Martin Vigoureux
   Intended Status: Proposed Standard                    Alcatel-Lucent
   Expiration Date: January 12, 2009                     Kohei Shiomoto
                                                                    NTT
                                                       Deborah Brungard
                                                                    ATT
                                                     Jean-Louis Le Roux
                                                         France Telecom
                                                          July 13, 2008

        Generalized Multi-Protocol Label Switching (GMPLS) Protocol
      Extensions for Multi-Layer and Multi-Region Networks (MLN/MRN)

               draft-ietf-ccamp-gmpls-mln-extensions-02.txt

Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
   aware will be disclosed, in accordance with Section 6 of BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on January 12, 2009.

Copyright Notice

   Copyright (C) The IETF Trust (2008).

Abstract

   There are requirements for the support of networks ccomprising LSRs
   with different data plane switching layers controlled by a single
   Generalized Multi Protocol Label Switching (GMPLS) control plane
   instance, referred to as GMPLS Multi-Layer Networks/Multi-Region


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   Networks (MLN/MRN). This document defines extensions to GMPLS routing
   and signaling protocols so as to support the operation of GMPLS
   Multi-Layer/Multi-Region Networks.

Table of Content

   1. Introduction................................................ 2
   2. Summary of the Requirements and Evaluation.................. 3
   3. Interface adaptation capability descriptor (IACD)........... 3
   4. Multi-Region Signaling...................................... 6
   5. Virtual TE link............................................. 8
   6. Backward Compatibility...................................... 13
   7. Security Considerations..................................... 13
   8. IANA Considerations Sections................................ 13
   9. References.................................................. 14

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].

   In addition the reader is assumed to be familiar with [RFC3945],
   [RFC3471], [RFC4201], [RFC4202], [RFC4203], [RFC4205], and [RFC4206].


1. Introduction

   Generalized Multi-Protocol Label Switching (GMPLS) [RFC3945]
   extends MPLS to handle multiple switching technologies: packet
   switching (PSC), layer-two switching (L2SC), TDM switching (TDM),
   wavelength switching (LSC) and fiber switching (FSC). A GMPLS
   switching type (PSC, TDM, etc.) describes the ability of a node to
   forward data of a particular data plane technology, and uniquely
   identifies a control plane region. LSP Regions are defined in
   [RFC4206]. A network comprised of multiple switching types (e.g. PSC
   and TDM) controlled by a single GMPLS control plane instance is
   called a Multi-Region Network (MRN).

   A data plane layer is a collection of network resources capable of
   terminating and/or switching data traffic of a particular format.
   For example, LSC, TDM VC-11 and TDM VC-4-64c represent three
   different layers. A network comprising transport nodes with
   different data plane switching layers controlled by a single GMPLS
   control plane instance is called a Multi-Layer Network (MLN).

   The applicability of GMPLS to multiple switching technologies
   provides the unified control and operations for both LSP provisioning
   and recovery. This document covers the elements of a single GMPLS


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   control plane instance controlling multiple layers within a given TE
   domain. A CP instance can serve one, two or more layers. Other
   possible approaches such as having multiple CP instances serving
   disjoint sets of layers are outside the scope of this document.

   The next sections provide the procedural aspects in terms of routing
   and signaling for such environments as well as the extensions
   required to instrument GMPLS to provide the capabilities for MLM/MRN
   unified control. The rationales and requirements for Multi-
   Layer/Region networks are set forth in [MLN-REQ]. These requirements
   are evaluated against GMPLS protocols in [MLN-EVAL] and several
   areas where GMPLS protocol extensions are required are identified.
   This document defines GMPLS routing and signaling extensions so as
   to cover GMPLS MLN/MRN requirements.

2. Summary of the Requirements and Evaluation

   As identified in [MLN-EVAL] most of MLN/MRN requirements rely on
   mechanisms and procedures that are outside the scope of the GMPLS
   protocols, and thus do not require any GMPLS protocol extensions.
   They rely on local procedures and policies, and on specific TE
   mechanisms and algorithms, which are outside the scope of GMPLS
   protocols.

   Four areas for extensions of GMPLS protocols and procedures have been
   identified:

      - GMPLS routing extension for the advertisement of the
        internal adjustment capability of hybrid nodes.

      - GMPLS signaling extension for constrained multi-region
        signaling (SC inclusion/exclusion).

      - GMPLS signaling extension for the setup/deletion of
        Virtual TE-links (as well as exact trigger for its actual
        provisioning).

      - GMPLS routing and signaling extension for graceful TE-link
        deletion (covered in [GR-TELINK]).

   The first three requirements are addressed in Sections 3, 4 and 5,
   respectively, of this document. The fourth requirement is addressed
   in [GR-TELINK]. Companion documents address GMPLS OAM aspects that
   have been identified in [MLN-EVAL].

3. Interface adaptation capability descriptor (IACD)

   In the MRN context, nodes supporting more than one switching
   capability on at least one interface are called Hybrid nodes. Hybrid


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   nodes contain at least two distinct switching elements that are
   interconnected by internal links to provide adaptation between the
   supported switching capabilities. These internal links have finite
   capacities and must be taken into account when computing the path of
   a multi-region TE-LSP.

   The advertisement of the internal adaptation capability is required
   as it provides critical information when performing multi-region path
   computation.

3.1 Overview

   In an MRN environment, some LSRs could contain, under the control of
   a single GMPLS instance, multiple switching capabilities such as PSC
   and TDM or PSC and Lambda Switching Capability (LSC).

   These nodes, hosting multiple Interface Switching Capabilities
   (ISC), just like other nodes (hosting a single Interface Switching
   Capability) are required to hold and advertise resource information
   on link states and topology. They also may have to consider certain
   portions of internal node resources to terminate hierarchical label
   switched paths (LSPs), since circuit switch capable units such as
   TDMs, LSCs, and FSCs require rigid resources. For example, a node
   with PSC+LSC hierarchical switching capability can switch a Lambda
   LSP but may not be able to can never terminate the Lambda LSP if
   there is no unused adaptation capability between the LSC and the PSC
   switching capabilities.

   Another example occurs when L2SC (Ethernet) switching can be adapted
   in LAPS X.86 and GFP for instance before reaching the TDM switching
   matrix. Similar circumstances can occur, if a switching fabric that
   supports both PSC and L2SC functionalities is assembled with LSC
   interfaces enabling "lambda" encoding. In the switching fabric, some
   interfaces can terminate Lambda LSPs and perform frame (or cell)
   switching whilst other interfaces can terminate Lambda LSPs and
   perform packet switching.

   Therefore, within multi-region networks, the advertisement of the
   so-called adaptation capability to terminate LSPs (not the interface
   capability since the latter can be inferred from the bandwidth
   available for each switching capability) provides critical
   information to take into account when performing multi-region path
   computation. This concept enables a node to discriminate the remote
   nodes (and thus allows their selection during path computation) with
   respect to their adaptation capability e.g. to terminate LSPs at the
   PSC or LSC level.





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   Hence, we introduce the idea of discriminating the (internal)
   adaptation capability from the (interface) switching capability by
   considering an interface adaptation capability descriptor.

   A more detailed problem statement can be found in [MLN-EVAL].

3.2 Interface Adjustment Capability Descriptor (IACD) Format

   The interface adjustment capability descriptor (IACD) provides the
   information for the forwarding/switching) capability only.

3.2.1 OSPF

   In OSPF, the IACD sub-TLV is defined as a sub-TLV of the Link TLV
   (see [RFC3630]), with type TBD. The IACD sub-TLV format is defined
   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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Switching Cap |   Encoding    | Switching Cap |   Encoding    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 0              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 1              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 2              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 3              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 4              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 5              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 6              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 7              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |        Adjustment Capability-specific information             |
   |                  (variable)                                   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Where:

   - first Switching Capability (SC) field (byte 1): lower switching
     capability (as defined for the existing ISC sub-TLV)
   - first Encoding field (byte 2): as defined for the existing ISC




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     sub-TLV
   - second SC value (byte 3): upper switching capability  (new)
   - second encoding value (byte 4): set to the encoding of the
     available adaptation pool and to 0xFF when the corresponding SC
     value has no access to the wire (i.e. there is no ISC sub-TLV for
     this upper switching capability)

   Multiple IACD sub-TLVs may be present within a given TE Link TLV
   and the bandwidth simply provides an indication of resources still
   available to perform insertion/ extraction for a given adjustment
   (pool concept).

3.2.2 IS-IS

   In IS-IS, the IACD sub-TLV is a sub-TLV of the Extended IS
   Reachability TLV (see [RFC3784]) with type TBD. The IACD sub-TLV
   format is defined 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Switching Cap |   Encoding    | Switching Cap |   Encoding    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 0              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 1              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 2              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 3              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 4              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 5              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 6              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Max LSP Bandwidth at priority 7              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |        Adjustment Capability-specific information             |
   |                  (variable)                                   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Where the fields have the same processing and interpretation rules as
   for Section 3.2.1.

   Multiple IACD sub-TLVs may be present within a given extended IS
   reachability TLV and the bandwidth simply provides an indication of



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   resources still available to perform insertion/ extraction for a
   given adjustment (pool concept).

4. Multi-Region Signaling

   Section 8.2 of [RFC4206] specifies that when a region boundary node
   receives a Path message, the node determines whether or not it is at
   the edge of an LSP region with respect to the ERO carried in the
   message. If the node is at the edge of a region, it must then
   determine the other edge of the region with respect to the ERO,
   using the IGP database. The node then extracts from the ERO the
   subsequence of hops from itself to the other end of the region.

   The node then compares the subsequence of hops with all existing FA-
   LSPs originated by the node:
   - if a match is found, that FA-LSP has enough unreserved bandwidth
     for the LSP being signaled, and the PID of the FA-LSP is
     compatible with the PID of the LSP being signaled, the node uses
     that FA-LSP as follows. The Path message for the original LSP is
     sent to the egress of the FA-LSP. The PHOP in the message is the
     address of the node at the head-end of the FA-LSP. Before sending
     the Path message, the ERO in that message is adjusted by removing
     the subsequence of the ERO that lies in the FA-LSP, and replacing
     it with just the end point of the FA-LSP.
   - if no existing FA-LSP is found, the node sets up a new FA-LSP.
     That is, it initiates a new LSP setup just for the FA-LSP.

   Note: compatible PID implies that traffic can be processed by both
   ends of the FA-LSP without drop.

   Applying this procedure, in a MRN environment MAY lead to setup one-
   hop FA-LSPs between each node. Therefore, considering that the path
   computation is able to take into account richness of information with
   regard to the SC available on given nodes belonging to the path, it
   is consistent to provide enough signaling information to indicate the
   SC to be used and on over which link. Particularly, in case a TE
   link has multiple SC advertised as part of its ISCD sub-TLVs, an ERO
   does not allow selecting a particular SC.

   Limiting modifications to existing RSVP-TE procedures [RFC3473] and
   referenced, this document defines a new sub-object of the eXclude
   Route Object (XRO), see [RFC4874], called Switching Capability sub-
   object. This sub-object enables (when desired) the explicit
   identification of (at least one) switching capability to be excluded
   from the resource selection process described here above.

   Including this sub-object as part of the XRO that explicitly
   indicates which SCs have to be excluded (before initiating the
   procedure described here above) over a specified TE link solves the


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   ambiguous choice among SCs that are potentially used along a given
   path and give the possibility to optimize resource usage on a multi-
   region basis. Note that implicit SC inclusion is easily supported by
   explicitly excluding other SCs (e.g. to include LSC, it is required
   to exclude PSC, L2SC, TDM and FSC).

4.1 SC Subobject Encoding

   The contents of an EXCLUDE_ROUTE object defined in [RFC4874] are a
   series of variable-length data items called subobjects. This
   document defines the SC subobject of the XRO (Type TBD), its
   encoding and processing.

   Subobject Type TBD: Switching Capability

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |L|    Type     |     Length    |   Attribute   | Switching Cap |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      L
           0 indicates that the attribute specified MUST be excluded
           1 indicates that the attribute specified SHOULD be avoided

      Attribute

           0 reserved value

           1 indicates that the specified SC should be excluded or
             avoided with respect to the preceding numbered (Type 1 or
             Type 2) or unnumbered interface (Type) subobject

      Switching Cap (8-bits)

           Switching Capability value to be excluded.

   This sub-object must follow the set of numbered or unnumbered
   interface sub-objects to which this sub-object refers. In case, of
   loose hop ERO subobject, the XRO sub-object must precede the loose-
   hop sub-object identifying the tail-end node/interface of the
   traversed region(s).

   Furthermore, it is expected, when label sub-object are following
   numbered or unnumbered interface sub-objects, that the label value is
   compliant with the SC capability to be explicitly excluded.

5. Virtual TE link



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   Two techniques can be used for the setup operation and maintenance of
   Virtual TE links. The corresponding GMPLS protocols extensions are
   described in this section.

5.1 Edge-to-edge Association

   This approach that does not require state maintenance on transit LSRs
   relies on extensions to the GMPLS RSVP-TE Call procedure (see
   [RFC4974]).

   This technique consists of exchanging identification and TE
   attributes information directly between TE link end points. These TE
   link end-points correspond to the LSP head-end and tail-end points of
   of the LSPs that will be established. The end-points MUST belong to
   the same (LSP) region through the establishment of a call between
   terminating LSRs.

   Once the call is established the resulting association populates the
   local TEDB and the resulting TE link is advertised as any other TE
   link. The latter can then be used to attract traffic. Once an upper
   layer/lower region LSP makes use of this TE link. A set of one or
   more LSPs must be initially established before the FA LSP can be used
   for nesting the incoming LSP.

   In order to distinguish usage of such call from a classical call (as
   defined e.g. in [RFC4139]), a CALL ATTRIBUTES object is introduced.

5.1.1 CALL_ATTRIBUTES Object

   The CALL_ATTRIBUTES object is used to signal attributes required in
   support of a call, or to indicate the nature or use of a call. It is
   built on the LSP-ATTRIBUTES object defined in [RFC4420].

   The CALL_ATTRIBUTES object class is 201 (TBD by IANA) of the form
   11bbbbbb. This C-Num value (see [RFC2205], Section 3.10) ensures that
   LSRs that do not recognize the object pass it on transparently.

   One C-Type is defined, C-Type = 1 for CALL Attributes. This object is
   optional and may be placed on Notify messages to convey additional
   information about the desired attributes of the call.

5.1.2 Processing

   Specifically, if an egress (or intermediate) LSR does not support the
   object, it forwards it unexamined and unchanged.  This facilitates
   the exchange of attributes across legacy networks that do not support
   this new object.




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   The CALL_ATTRIBUTES object may be used to report call operational
   state on a Notify message.

      CALL_ATTRIBUTES class = 201, C-Type = 1

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      //                       Attributes TLVs                       //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      The Attributes TLVs are encoded as described in Section 3.

5.1.3 Attributes TLVs

   Attributes carried by the CALL_ATTRIBUTES object are encoded within
   TLVs. One or more TLVs may be present in each object.

   There are no ordering rules for TLVs, and no interpretation should be
   placed on the order in which TLVs are received.

   Each TLV is encoded 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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             Type              |           Length              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      //                            Value                            //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Type

        The identifier of the TLV.

      Length

        The total length of the TLV fields in bytes. If no Value field
        is present the Length field contains the value four (4).
        A Value field whose length is not a multiple of four MUST be
        padded with a Reserved field so that the Length is a multiple
        of four-octet. Thus, the Length MUST be at least 4, and MUST
        be a multiple of 4.

      Value


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        The data field for the TLV padded as described above.

5.1.4 Attributes Flags TLV

   The TLV Type 1 indicates the Attributes Flags TLV. Other TLV types
   may be defined in the future with type values assigned by IANA (see
   Section 8). The Attributes Flags TLV may be present in a
   CALL_ATTRIBUTES object.

   The Attribute Flags TLV value field is an array of units of 32 flags
   numbered from the most significant bit as bit zero. The Length field
   for this TLV is therefore always a multiple of 4 bytes, regardless of
   the number of bits carried and no padding is required.

   Unassigned bits are considered as reserved and MUST be set to zero on
   transmission by the originator of the object. Bits not contained in
   the TLV MUST be assumed to be set to zero. If the TLV is absent
   either because it is not contained in the CALL_ATTRIBUTES object or
   because this object is itself absent, all processing MUST be
   performed as though the bits were present and set to zero. That is to
   say, assigned bits that are not present either because the TLV is
   deliberately foreshortened or because the TLV is not included MUST be
   treated as though they are present and are set to zero.

5.1.5 Call inheritance Flag

   This document introduces a specific flag (MSB position bit 0) of the
   Attributes Flags TLV, to indicate that the association initiated
   between the end-points belonging to a call results into a (virtual)
   TE link advertisement.

   The Call inheritance flag MUST be set to 1 in order to indicate that
   the established association is to be translated into a TE link
   advertisement. The value of this flag is by default set to 1. Setting
   this flag to 0 results in a hidden TE link or in deleting the
   corresponding TE link advertisement (by setting the corresponding
   Opaque LSA Age to MaxAge).

   The notify message used for establishing the association is defined
   as per [RFC4974]. Additionally, the notify message must carry an
   LSP_TUNNEL_INTERFACE_ID Object, that allows identifying unnumbered
   FA-LSPs ([RFC3477], [RFC4206]) and numbered FA-LSPs ([RFC4206]).

5.2. Soft FA approach

   The Soft Forwarding Adjacency (Soft FA) approach consists of setting
   up the FA LSP at the control plane level without actually committing
   resources in the data plane. This means that the corresponding LSP
   exists only in the control plane domain. Once such FA is established


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   the corresponding TE link can be advertized following the procedures
   described in [RFC4206].

   There are two techniques to setup Soft FAs: the first one consists in
   setting up the FA LSP by precluding resource commitment during its
   establishment. The second technique consists in making use of path
   provisioned LSPs only. In this case, there is no associated resource
   demand during the LSP establishment. This can be considered as the
   RSVP-TE equivalent of the Null service type specified in [RFC2997].

5.2.1 Pre-planned LSP Flag

   The LSP ATTRIBUTES object and Attributes Flags TLV are defined in
   [RFC4420]. The present document defines a new flag, the pre-planned
   LSP Flag, in the existing Attributes Flags TLV (numbered as Type 1).

   The position of this flag is TBD in accordance with IANA assignment.
   This flag, part of the LSP_REQUIRED ATTRIBUTE object, follows
   processing of [RFC4420] for that object. That is, LSRs that do not
   recognize the object reject the LSP setup effectively saying that
   they do not support the attributes requested. Indeed, the newly
   defined attribute requires examination at all transit LSRs.

   The pre-planned LSP Flag can take one of the following values:

   o) When set to 0 this means that the LSP should be fully provisioned.
   Absence of this flag (hence corresponding TLV) is therefore compliant
   with the signaling message processing per [RFC3473])

   o) When set to 1 this means that the LSP should be provisioned in the
   control plane only.

   If an LSP is established with the pre-planned Flag set to 1, no
   resources are committed at the data plane level. The operation of
   committing data plane resources occurs by re-signaling the same LSP
   with the pre-planned Flag set to 0. It is RECOMMENDED that no other
   modifications are made to other RSVP objects during this operation.
   That is each intermediate node, processing a Flag transiting from 1
   to 0 shall only be concerned with the commitment of data plane
   resources and no other modification of the LSP properties and/or
   attributes.

   If an LSP is established with the pre-planned Flag set to 0, it MAY
   be re-signaled by setting the Flag to 1.

5.2.2 Path Provisioned LSPs

   There is a difference in between an LSP that is established with 0
   bandwidth (path provisioning) and an LSP that is established with a


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   certain bandwidth value not committed at the data plane level (i.e.
   pre-planned LSP).

   However, the former is currently not possible using the GMPLS
   protocol suite (following technology specific SENDER_TSPEC/FLOWSPEC
   definition). Indeed, Traffic Parameters such as those defined in [RFC
   4606] do not support setup of 0 bandwidth LSPs.

   Mechanisms for provisioning (pre-planned or not) LSP with 0 bandwidth
   is straightforward for PSC the SENDER_TSPEC/FLOWSPEC, the Peak Data
   Rate field of Int-Serv objects, see [RFC2210], is set to 0. For L2SC
   LSP, the CIR, EIR, CBS, and EBS must be set of 0 in the Type 2 sub-
   TLV of the Ethernet Bandwidth Profile TLV. In these cases, upon LSP
   resource commitment, actual traffic parameter values are used to
   perform corresponding resource reservation.

   For TDM and LSC LSP, a NULL Label value is used to prevent resource
   allocation at the data plane level. In these cases, upon LSP resource
   commitment, actual label value exchange is performed to commit
   allocation of timeslots/wavelengths.

6. Backward compatibility

   New objects and procedures defined in this document are running
   within a given TE domain. The latter is expected to run in the
   context of a consistent TE policy.

   In such TE domains, we distinguish between edge LSRs and intermediate
   LSrs. Edge LSRs must be able to process Call Attribute as defined in
   section 5.1 if this is method selected or creating edge-to-edge
   associations. In that domain, intermediate LSRs are by definition
   transparent to the Call processing.

   In case the Soft FA method is used for the creation of Virtual TE
   links, edge and intermediate LSRs must support processing of the LSP
   ATTRIBUTE object per Section 5.2.

7. Security Considerations

   In its current version, this memo does not introduce new security
   consideration from the ones already detailed in the GMPLS protocol
   suite.

   The applicability of the proposed GMPLS extensions is limited to
   single TE domain. Such domain is under the administrative authority
   of a single entity. In this context, multi-switching layer comprised
   within such TE domain are under the control of a single GMPLS control
   plane instance.



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   Call initiation as depicted in section 5.1, MUST strictly remain
   under control of the TE domain administrator. To prevent any abuse of
   Call setup, edge nodes MUST ensure isolation of their call controller
   (i.e. the latter is not reachable via external TE domains). To
   further prevent man-in-the-middle attack, security associations MUST
   be established between edge nodes initiating and terminating calls.
   For this purpose, IKE [RFC4306] MUST be used for performing mutual
   authentication and establishing and maintaining these security
   associations.

8. IANA Considerations section

   TBD.

9. References

9.1 Normative References

   [RFC2205]  Braden, R., et al., "Resource ReSerVation Protocol
              (RSVP) -- Version 1 Functional Specification",
              RFC2205, September 1997.

   [RFC2210]  Wroclawski, J., "The Use of RSVP with IETF
              Integrated Services", RFC2210, September 1997.

   [RFC3471]  L.Berger et al., "Generalized Multi-Protocol Label
              Switching (GMPLS) - Signaling Functional Description",
              RFC3471, January 2003.

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

   [RFC3630]  D.Katz et al., "Traffic Engineering (TE) Extensions to
              OSPF Version 2," RFC3630, September 2003.

   [RFC3784]  Smit, H. and T. Li, "Intermediate System to
              Intermediate System (IS-IS) Extensions for Traffic
              Engineering (TE)", RFC3784, June 2004.

   [RFC3945]  Mannie, E. and al., "Generalized Multi-Protocol Label
              Switching (GMPLS) Architecture", RFC3945, October 2004.

   [RFC4201]  K.Kompella, et al., "Link Bundling in MPLS Traffic
              Engineering", RFC4201, October 2005.

   [RFC4202]  K.Kompella (Editor), Y. Rekhter (Editor) et al. "Routing
              Extensions in Support of Generalized MPLS", RFC4202,
              October 2005.

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   [RFC4203]  Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions
              in Support of Generalized Multi-Protocol Label Switching
              (GMPLS)", RFC4203, October 2005.

   [RFC4205]  Kompella, K., Ed., and Y. Rekhter, Ed., "Intermediate
              System to Intermediate System (IS-IS) Extensions in
              Support of Generalized Multi-Protocol Label Switching
              (GMPLS)", RFC4205, October 2005.

   [RFC4206]  K.Kompella and Y.Rekhter, "LSP Hierarchy with Generalized
              MPLS TE", RFC4206, October 2005.

   [RFC4420]  A.Farrel et al., "Encoding of Attributes for
              Multiprotocol Label Switching (MPLS) Label Switched Path
              (LSP) Establishment Using Resource ReserVation Protocol-
              Traffic Engineering (RSVP-TE)", RFC 4420, February 2006.

   [RFC4428]  D.Papadimitriou et al. "Analysis of Generalized Multi-
              Protocol Label Switching (GMPLS)-based Recovery
              Mechanisms (including Protection and Restoration)",
              RFC4428, March 2006.

   [RFC4874]  C.Y.Lee et al. "Exclude Routes - Extension to RSVP-TE,"
              RFC4874, April 2007.

   [RFC4974]  D.Papadimitriou and A.Farrel, "Generalized MPLS (GMPLS)
              RSVP-TE Signaling Extensions in support of Calls,"
              RFC4974, August 2007.

9.2 Informative References

   [MLN-EVAL] J.-L. Leroux et al., "Evaluation of existing GMPLS
              Protocols against Multi Region and Multi Layer Networks
              (MRN/MLN)", Work in Progress, draft-ietf-ccamp-gmpls-mln-
              eval-06.txt.

   [MLN-REQ]  K.Shiomoto et al., "Requirements for GMPLS-based multi-
              region and multi-layer networks (MRN/MLN)", RFC5212,
              July 2008.

   [MLRT]     W.Imajuku et al., "Multilayer routing using multilayer
              switch capable LSRs, Work in Progress, draft-imajuku-ml-
              routing-02.txt.

Acknowledgments




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   The authors would like to thank Mr. Wataru Imajuku for the
   discussions on adaptation between regions [MLRT].

Authors' Addresses

   Dimitri Papadimitriou
   Alcatel-Lucent
   Copernicuslaan 50
   B-2018 Antwerpen, Belgium
   Phone : +32 3 240 8491
   Email: dimitri.papadimitriou@alcatel-lucent.be

   Martin Vigoureux
   Alcatel-Lucent
   Route de Villejust
   91620 Nozay, France
   Tel : +33 1 30 77 26 69
   Email: martin.vigoureux@alcatel-lucent.fr

   Kohei Shiomoto
   NTT
   3-9-11 Midori-cho
   Musashino-shi, Tokyo 180-8585, Japan
   Phone: +81 422 59 4402
   Email: shiomoto.kohei@lab.ntt.co.jp

   Deborah Brungard
   ATT
   Rm. D1-3C22 - 200 S. Laurel Ave.
   Middletown, NJ 07748, USA
   Phone: +1 732 420 1573
   Email: dbrungard@att.com

   Jean-Louis Le Roux
   France Telecom
   Avenue Pierre Marzin
   22300 Lannion, France
   Phone: +33 (0)2 96 05 30 20
   Email: jean-louis.leroux@rd.francetelecom.com

Contributors

   Eiji Oki
   NTT Network Service Systems Laboratories
   3-9-11 Midori-cho
   Musashino-shi, Tokyo 180-8585, Japan
   Phone : +81 422 59 3441
   Email: oki.eiji@lab.ntt.co.jp



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   Ichiro Inoue
   NTT Network Service Systems Laboratories
   3-9-11 Midori-cho
   Musashino-shi, Tokyo 180-8585, Japan
   Phone : +81 422 59 6076
   Email: ichiro.inoue@lab.ntt.co.jp

   Emmanuel Dotaro
   Alcatel-Lucent France
   Route de Villejust
   91620 Nozay, France
   Phone : +33 1 6963 4723
   Email: emmanuel.dotaro@alcatel-lucent.fr

   Gert Grammel
   Alcatel-Lucent SEL
   Lorenzstrasse, 10
   70435 Stuttgart, Germany
   Email: gert.grammel@alcatel-lucent.de
































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