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     Network Working Group                             Dimitri Papadimitriou
     Internet Draft                                         Martin Vigoureux
     Intended Status: Standards Track                         Alcatel-Lucent
     Expiration Date: April 30, 2009                          Kohei Shiomoto
                                                                         NTT
                                                            Deborah Brungard
                                                                         ATT
                                                          Jean-Louis Le Roux
                                                              France Telecom
                                                            October 31, 2008
     
     
            Generalized Multi-Protocol Label Switching (GMPLS) Protocol
           Extensions for Multi-Layer and Multi-Region Networks (MLN/MRN)
     
                 draft-ietf-ccamp-gmpls-mln-extensions-03.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.
     
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        This Internet-Draft will expire on April 30, 2009.
     
     Copyright Notice
     
        Copyright (C) The IETF Trust (2008).
     
     Abstract
     
     
     
     
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        There are requirements for the support of networks comprising 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
        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. It covers the elements of a single GMPLS control
        plane instance controlling multiple LSP regions or layers within a
        single TE domain.
     
     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
     
     
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        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
        control plane instance controlling multiple layers within a given TE
        domain. A TE domain is defined as group of LSRs that enforces a
        common TE policy. 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 in [MLN-EVAL]:
     
        o GMPLS routing extension for the advertisement of the internal
          adjustment capability of hybrid nodes. See Section 3.2.2 of [MLN-
          EVAL].
     
        o GMPLS signaling extension for constrained multi-region signaling
          (SC inclusion/exclusion). See Section 3.2.1 of [MLN-EVAL].
     
        o GMPLS signaling extension for the setup/deletion of Virtual TE-
     
     
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          links (as well as exact trigger for its actual provisioning). See
          Section 3.1.1.2 of [MLN-EVAL].
     
        o GMPLS routing and signaling extension for graceful TE-link
          deletion (covered in [GR-TELINK]). See Section 3.1.1.3 of [MLN-
          EVAL].
     
        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
        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
     
     
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        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.
     
        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)
     
        The interface adjustment capability descriptor (IACD) provides the
        information for the forwarding/switching) capability only.
     
        Note that the addition of the IACD as TE link attributes does not
        modify format/messaging and processing associated to the Interface
        Switching Capability Descriptor (ISCD) defined in [RFC4202].
     
     3.2.1 OSPF
     
        In OSPF, the IACD sub-TLV is defined as an optional sub-TLV of the TE
        Link TLV (Type 2, see [RFC3630]), with Type 24 (to be assigned by
        IANA) and variable length.
     
        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              |
     
     
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         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
         |                  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)                                   |
         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     
           Switching Capability (SC) field (byte 1) - 8 bits
     
              Indicates the lower switching capability (as defined for the
              existing ISC sub-TLV) first Encoding field (byte 2): as defined
              for the existing ISC sub-TLV.
     
           Encoding (byte 2) - 8 bits
     
              Contains one of the values specified in Section 3.1.1 of
              [GMPLS-SIG] and updates.
     
           Switching Capability (SC) field (byte 3) - 8 bits
     
              Indicates the upper switching capability.
     
           Encoding (byte 4) - 8 bits
     
              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.
     
           Other fields MUST be processed as specified in [RFC4202] and
           [RFC4203].
     
        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).
     
     
     
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        The presence of the IACD sub-TLV as part of the TE Link TLV does not
        modify format/messaging and processing associated to the ISCD defined
        in [RFC4203].
     
     3.2.2 IS-IS
     
        In IS-IS, the IACD sub-TLV is an optional sub-TLV of the Extended IS
        Reachability TLV (see [RFC3784]) with Type 24 (to be assigned by
        IANA).
     
        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
        resources still available to perform insertion/ extraction for a
        given adjustment (pool concept).
     
        The presence of the IACD sub-TLV as part of the extended IS
     
     
     
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        reachability TLV does not modify format/messaging and processing
        associated to the ISCD defined in [RFC4205].
     
     4. Multi-Region Signaling
     
        Section 6.2 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:
     
        o 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.
     
        o 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 the procedure of [RFC4206], 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.
     
     
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        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
        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 Switching Capability (SC) subobject of the XRO
        (Type 35), 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).
     
     
     
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        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
     
        A virtual TE link is defined as a TE link between two upper layer
        nodes that is not associated with a fully provisioned FA-LSP in a
        lower layer. A virtual TE link is advertised as any TE link,
        following the rules in [RFC4206] defined for fully provisioned TE
        links. A virtual TE link represents thus the potentiality to setup an
        FA-LSP in the lower layer to support the TE link that has been
        advertised. In particular, the flooding scope of a virtual TE link is
        within an IGP area, as is the case for any TE link.
     
        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. The procedures described in this section
        complement those defined in [RFC4206] and [HIER-BIS].
     
     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 using procedures defined in
        [RFC4206] 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
     
     
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        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.
     
        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              |
         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     
     
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         |                                                               |
         //                            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
     
              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
     
     
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        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 Forwarding Adjacency (Soft FA)
     
        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
        the corresponding TE link can be advertised following the procedures
        described in [RFC4206].
     
        There are two techniques to setup Soft FAs:
     
        o The first one consists in setting up the FA LSP by precluding
          resource commitment during its establishment.
     
        o 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.
     
     
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        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
        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
     
     
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        allocation of timeslots/wavelengths.
     
     6. Backward compatibility
     
        New objects and procedures defined in this document are running
        within a given TE domain. The latter, defined as group of LSRs that
        enforces a common TE policy, is thus expected to run in the context
        of a consistent TE policy. Specification for a consistent TE policy
        is outside the scope of this document.
     
        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
     
        This document does not introduce any new security consideration from
        the ones already detailed in [MPLS-SEC] that describes the MPLS and
        GMPLS security threats, the related defensive techniques, and the
        mechanisms for detection and reporting. Indeed, the applicability of
        the proposed GMPLS extensions is limited to single TE domain. Such
        domain is under the authority of a single administrative entity. In
        this context, multi-switching layer comprised within such TE domain
        are under the control of a single GMPLS control plane instance.
     
        Nevertheless, 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
     
     8.1 RSVP
     
        IANA has made the following assignments in the "Class Names, Class
        Numbers, and Class Types" section of the "RSVP PARAMETERS" registry
     
     
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        located at http://www.iana.org/assignments/rsvp-parameters.
     
        This document introduces a new class named CALL_ATTRIBUTES has been
        created in the 11bbbbbb range (201) with the following definition:
     
        Class Number  Class Name                            Reference
        ------------  -----------------------               ---------
        201           CALL ATTRIBUTES                       [This I-D]
     
                      Class Type (C-Type):
     
                      1   Call Attributes                   [This.I-D]
     
        This document introduces a new subobject for the EXCLUDE_ROUTE object
        [RFC4874], C-Type 1.
     
        Subobject Type   Subobject Description
        --------------   ---------------------
        35               Switching Capability (SC)
     
     8.2 OSPF
     
        IANA maintains Open Shortest Path First (OSPF) Traffic Engineering
        TLVs Registries included below for Top level Types in TE LSAs and
        Types for sub-TLVs of TE Link TLV (Value 2).
     
        This document defines the following sub-TLV of TE Link TLV (Value 2)
     
        Value  Sub-TLV
        -----  -------------------------------------------------
        24     Interface Adjustment Capability Descriptor (IACD)
     
     8.3 IS-IS
     
        This document defines the following new sub-TLV type of top-level TLV
        22 that need to be reflected in the ISIS sub-TLV registry for TLV 22:
     
        Type   Description                                        Length
        ----   -------------------------------------------------  ------
        24     Interface Adjustment Capability Descriptor (IACD)  Variable
     
     9. References
     
     9.1 Normative References
     
     
     
     
     
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        [GR-TELINK] Ali, Z., et al., "Graceful Shutdown in MPLS and
                   Generalized MPLS Traffic Engineering Networks", draft-
                   ietf-ccamp-mpls-graceful-shutdown, Work in progress.
     
        [HIER-BIS] Shiomoto, K., and Farrel, A., "Procedures for Dynamically
                   Signaled Hierarchical Label Switched Paths", draft-ietf-
                   ccamp-lsp-hierarchy-bis, Work in progress.
     
        [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]  Berger, L., 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]  Katz, D., 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]  Kompella, K., et al., "Link Bundling in MPLS Traffic
                   Engineering", RFC4201, October 2005.
     
        [RFC4202]  Kompella, K., Ed., and Rekhter, Y. Ed., "Routing
                   Extensions in Support of Generalized MPLS", RFC4202,
                   October 2005.
     
        [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
     
     
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                   Support of Generalized Multi-Protocol Label Switching
                   (GMPLS)", RFC4205, October 2005.
     
        [RFC4206]  Kompella, K., and Rekhter, Y., "LSP Hierarchy with
                   Generalized MPLS TE", RFC4206, October 2005.
     
        [RFC4420]  Farrel, A., 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]  Papadimitriou, D., et al. "Analysis of Generalized Multi-
                   Protocol Label Switching (GMPLS)-based Recovery
                   Mechanisms (including Protection and Restoration)",
                   RFC4428, March 2006.
     
        [RFC4874]  Lee, C.Y., et al. "Exclude Routes - Extension to RSVP-TE,"
                   RFC4874, April 2007.
     
        [RFC4974]  Papadimitriou, D., and Farrel, A., "Generalized MPLS
                   (GMPLS) RSVP-TE Signaling Extensions in support of Calls,"
                   RFC4974, August 2007.
     
     9.2 Informative References
     
        [MLN-EVAL] Leroux, J.-L., et al., "Evaluation of existing GMPLS
                   Protocols against Multi Region and Multi Layer Networks
                   (MRN/MLN)", RFC 5339, September 2008.
     
        [MLN-REQ]  Shiomoto, K., et al., "Requirements for GMPLS-based multi-
                   region and multi-layer networks (MRN/MLN)", RFC5212,
                   July 2008.
     
        [MPLS-SEC] Fang, L. Ed., "Security Framework for MPLS and GMPLS
                   Networks", draft-ietf-mpls-mpls-and-gmpls-security-
                   framework-03.txt, Work in progress.
     
        [MLRT]     Imajuku, W., et al., "Multilayer routing using multilayer
                   switch capable LSRs", draft-imajuku-ml-routing-02.txt,
                   Work in Progress.
     
     Acknowledgments
     
        The authors would like to thank Mr. Wataru Imajuku for the
        discussions on adaptation between regions [MLRT].
     
     
     
     
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     Author's Addresses
     
        Dimitri Papadimitriou
        Alcatel-Lucent Bell
        Copernicuslaan 50
        B-2018 Antwerpen, Belgium
        Phone: +32 3 2408491
        E-mail: 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
     
        Ichiro Inoue
     
     
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        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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     Full Copyright Statement
     
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