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    INTERNET DRAFT                               Dimitri Papadimitriou
                                                      Martin Vigoureux
    Intended Status: Standards Track                    Alcatel-Lucent
    Updates: 4202, 4203, 4206, 4874, 4974, 5307         Kohei Shiomoto
    Expiration Date: August 20 2010                                NTT
    Creation Date: February 21 2010                   Deborah Brungard
                                                                   ATT
                                                    Jean-Louis Le Roux
                                                        France Telecom
    
    
        Generalized Multi-Protocol Label Switching (GMPLS) Protocol
      Extensions for Multi-Layer and Multi-Region Networks (MLN/MRN)
    
               draft-ietf-ccamp-gmpls-mln-extensions-12.txt
    
    
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    Abstract
    
       There are specific requirements for the support of networks
       comprising Label Switching Routers (LSR) participating in
       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 Contents
    
       Abstract.....................................................2
       Table of Contents............................................2
       1. Introduction..............................................3
       2. Summary of the Requirements and Evaluation................4
       3. Interface adjustment capability descriptor (IACD).........5
          3.1. Overview.............................................5
          3.2. Interface Adjustment Capability Descriptor (IACD)....6
       4. Multi-Region Signaling....................................9
          4.1. XRO Subobjects......................................10
    
    
    
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       5. Virtual TE link..........................................13
          5.1. Edge-to-edge Association............................13
          5.2. Soft Forwarding Adjacency (Soft FA).................17
       6. Backward Compatibility...................................19
       7. Security Considerations..................................19
       8. IANA Considerations......................................20
          8.1 RSVP.................................................20
          8.2 OSPF.................................................21
          8.3 IS-IS................................................21
       9. References...............................................21
          9.1 Normative References.................................21
          9.2 Informative References...............................23
       Acknowledgments.............................................24
       Author's Addresses..........................................24
    
    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],
       [RFC4206], and [RFC5307].
    
    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 Label Switched Path
       (LSP) 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
       participating in different data plane switching layers
    
    
    
    
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       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 Label Switching Routers (LSR) that enforces a common
       TE policy. A Control Plane (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
       [RFC5212]. These requirements are evaluated against GMPLS
       protocols in [RFC5339] 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 [RFC5339], most MLN/MRN requirements rely on
       mechanisms and procedures (such as local procedures and
       policies, or specific TE mechanisms and algorithms) that are
       outside the scope of the GMPLS protocols, and thus do not
       require any GMPLS protocol extensions.
    
       Four areas for extensions of GMPLS protocols and procedures
       have been identified in [RFC5339]:
    
       o GMPLS routing extensions for the advertisement of the
         internal adjustment capability of hybrid nodes. See Section
         3.2.2 of [RFC5339].
    
       o GMPLS signaling extensions for constrained multi-region
         signaling (Switching Capability inclusion/exclusion). See
         Section 3.2.1 of [RFC5339]. An additional eXclude Route
         Object (XRO) Label subobject is also defined since absent
         from [RFC4874].
    
    
    
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       o GMPLS signaling extensions for the setup/deletion of Virtual
         TE-links (as well as exact trigger for its actual
         provisioning). See Section 3.1.1.2 of [RFC5339].
    
       o GMPLS routing and signaling extensions for graceful TE-link
         deletion. See Section 3.1.1.3 of [RFC5339].
    
       The first three requirements are addressed in Sections 3, 4,
       and 5 of this document, respectively. The fourth requirement is
       addressed in [GMPLS-RR] with additional context provided by
       [GR-TELINK].
    
    3. Interface adjustment capability descriptor (IACD)
    
       In the MRN context, nodes that have at least one interface that
       supports more than one switching capability are called Hybrid
       nodes [RFC5212]. The logical composition of a hybrid node
       contains at least two distinct switching elements that are
       interconnected by "internal links" to provide adjustment
       between the supported switching capabilities. These internal
       links have finite capacities that MUST be taken into account
       when computing the path of a multi-region TE-LSP. The
       advertisement of the internal adjustment 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 multiple
       switching capabilities such as PSC and TDM, or PSC and LSC, all
       under the control of a single GMPLS instance,
    
       These nodes, hosting multiple Interface Switching Capabilities
       (ISC) [RFC4202], are required to hold and advertise resource
       information on link states and topology, just like other nodes
       (hosting a single ISC). They may also have to consider some
       portions of internal node resources use to terminate
       hierarchical LSPs, since in circuit-switching technologies
       (such as TDM, LSC, and FSC) LSPs require the use of resources
       allocated in a discrete manner (as pre-determined by the
       switching type). For example, a node with PSC+LSC hierarchical
       switching capability can switch a lambda LSP, but cannot
       terminate the Lambda LSP if there is no available (i.e., not
       already in use) adjustment capability between the LSC and the
       PSC switching components. Another example occurs when L2SC
    
    
    
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       (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 adjustment capability to terminate LSPs (not the
       interface capability since the latter can be inferred from the
       bandwidth available for each switching capability) provides the
       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 adjustment capability e.g.
       to terminate LSPs at the PSC or LSC level.
    
       Hence, we introduce the capability of discriminating the
       (internal) adjustment capability from the (interface) switching
       capability by defining an Interface Adjustment Capability
       Descriptor (IACD).
    
       A more detailed problem statement can be found in [RFC5339].
    
    3.2. Interface Adjustment Capability Descriptor (IACD)
    
       The interface adjustment capability descriptor (IACD) provides
       the information for the forwarding/switching capability.
    
       Note that the addition of the IACD as a TE link attribute does
       not modify the format of the Interface Switching Capability
       Descriptor (ISCD) defined in [RFC4202], and does not change how
       the ISCD sub-TLV is carried in the routing protocols or how it
       is processed when it is received [RFC4201], [RFC4203].
    
       The receiving LSR uses its Link State Database to determine the
       IACD(s) of the far-end of the link. Different Interface
       Adjustment Capabilities at two ends of a TE link are allowed.
    
    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.
    
    
    
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       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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       | Lower SC      | Lower Encoding| Upper SC      | Upper 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)                          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    
          Lower Switching Capability (SC) field (byte 1) - 8 bits
    
             Indicates the Lower Switching Capability associated to
             the Lower Encoding field (byte 2). The value of the Lower
             Switching Capability field MUST be set to the value of
             Switching Capability of the ISCD sub-TLV advertized for
             this TE Link. If multiple ISCD sub-TLVs are advertized
             for that TE link, the Lower Switching Capability (SC)
             value MUST be set to the value of SC to which the
             adjustment capacity is associated.
    
          Lower Encoding (byte 2) - 8 bits
    
             Contains one of the LSP Encoding Type values specified in
             Section 3.1.1 of [RFC3471] and updates.
    
    
    
    
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          Upper Switching Capability (SC) field (byte 3) - 8 bits
    
             Indicates the Upper Switching capability. The Upper
             Switching Capability field MUST be set to one of the
             values defined in [RFC4202].
    
          Upper Encoding (byte 4) - 8 bits
    
             Set to the encoding of the available adjustment capacity
             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. The adjustment capacity is the set
             of resources associated to the upper switching
             capability.
    
          Max LSP Bandwidth
    
             The Maximum LSP Bandwidth is encoded as a list of eight
             4 octet fields in the IEEE floating point format [IEEE],
             with priority 0 first and priority 7 last. The units are
             bytes per second. Processing MUST follow the rules
             specified in [RFC4202].
    
          The Adjustment Capability-specific information - variable
    
             This field is defined so as to leave the possibility for
             future addition of technology-specific information
             associated to the adjustment capability.
    
          Other fields MUST be processed as specified in [RFC4202]
          and [RFC4203].
    
       The bandwidth values provide an indication of the resources
       still available to perform insertion/extraction for a given
       adjustment at a given priority (resource pool concept: set of
       shareable available resources that can be assigned
       dynamically).
    
       Multiple IACD sub-TLVs MAY be present within a given TE Link
       TLV.
    
       The presence of the IACD sub-TLV as part of the TE Link TLV
       does not modify the format/messaging and the processing
       associated to the ISCD sub-TLV defined in [RFC4203].
    
    3.2.2 IS-IS
    
    
    
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       In IS-IS, the IACD sub-TLV is an optional sub-TLV of the
       Extended IS Reachability TLV (see [RFC5305]) with Type 24 (to
       be assigned by IANA).
    
       The IACD sub-TLV format is identical to the OSPF sub-TLV format
       defined in Section 3.2.1. The fields of the IACD sub-TLV have
       the same processing and interpretation rules as defined in
       Section 3.2.1.
    
       Multiple IACD sub-TLVs MAY be present within a given extended
       IS reachability TLV.
    
       The presence of the IACD sub-TLV as part of the extended IS
       reachability TLV does not modify format/messaging and
       processing associated to the ISCD sub-TLV defined in [RFC5307].
    
    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 Explicit Route Object (ERO), using the IGP
       database. The node then extracts from the ERO the sub-sequence
       of hops from itself to the other end of the region.
    
       The node then compares the sub-sequence 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 G-PID of the
         FA-LSP is compatible with the G-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.
    
    
    
    
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         Note: compatible G-PID implies that traffic can be processed
         by both ends of the FA-LSP without dropping traffic after its
         establishment.
    
       Applying the procedure of [RFC4206], in a MRN environment MAY
       lead to setup single-hop FA-LSPs between each pair of nodes.
       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 over which link. Particularly, in case a
       TE link has multiple SCs advertised as part of its ISCD sub-
       TLVs, an ERO does not provide a mechanism to select a
       particular SC.
    
       In order to limit the 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 the 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 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 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).
    
       The approach followed here is to concentrate exclusions in XRO
       and inclusions in ERO. Indeed, the ERO specifies the
       topological characteristics of the path to be signaled. Usage
       of EXRS subobjects would also lead in the exclusion over
       certain portions of the LSP during the FA-LSP setup. Thus, it
       is more suited to extend generality of the elements excluded by
       the XRO but also prevent complex consistency checks as well as
       transpositions between EXRS and XRO at FA-LSP head-ends.
    
    4.1. XRO Subobjects
    
       The contents of an EXCLUDE_ROUTE object defined in [RFC4874]
       are a series of variable-length data items called subobjects.
    
    
    
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       This document defines the Switching Capability (SC) subobject
       of the XRO (Type 35), its encoding and processing. It also
       complements the subobjects defined in [RFC4874] with a Label
       subobject (Type 3).
    
    4.1.1 SC Subobject
    
       XRO subobject Type 35: 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=35   |    Length     |   Attribute   | Switching Cap |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    
          L (1 bit)
    
             0 indicates that the attribute specified MUST be excluded
    
             1 indicates that the attribute specified SHOULD be
               avoided
    
          Type (7 bits)
    
             The Type of the XRO SC subobject is 35.
    
          Length (8 bits)
    
             The total length of the subobject in bytes (including the
             Type and Length fields). The Length of the XRO SC
             subobject is 4.
    
          Attribute (8 bits)
    
             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.
    
    
    
    
    
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       The Switching Capability subobject MUST follow the set of one
       or more 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).
    
    4.1.2 Label Subobject
    
       The encoding of the XRO Label subobject is identical to the
       Label ERO subobject defined in [RFC3473] with the exception of
       the L bit. The XRO Label subobject is defined as follows:
    
       XRO Subobject Type 3: Label Subobject
    
        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=3     |    Length     |U|   Reserved  |   C-Type      |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                             Label                             |
       |                              ...                              |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    
          L (1 bit)
    
             0 indicates that the attribute specified MUST be
               excluded.
    
             1 indicates that the attribute specified SHOULD be
               avoided
    
          Type (7 bits)
    
             The Type of the XRO Label subobject is 3.
    
          Length (8 bits)
    
             The total length of the subobject in bytes (including the
             Type and Length fields). The Length is always divisible
             by 4.
    
          U (1 bit)
    
             See [RFC3471].
    
    
    
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          C-Type (8 bits)
    
             The C-Type of the included Label Object. Copied from the
             Label Object (see [RFC3471]).
    
          Label
    
           See [RFC3471].
    
    
       XRO Label subobjects MUST follow the numbered or unnumbered
       interface sub-objects to which they refer, and, when present,
       MUST also follow the Switching Capability sub-object.
    
       When XRO Label subobjects are following the Switching
       Capability sub-object, the corresponding label values MUST be
       compatible 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 [RFC5212]. 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 through the establishment
       of a call between terminating LSRs. These TE link end-points
       correspond to the LSP head-end and tail-end points of the LSPs
    
    
    
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       that will be established. The end-points MUST belong to the
       same (LSP) region.
    
       Once the call is established the resulting association
       populates the local Traffic Engineering DataBase (TEDB) and the
       resulting virtual TE link is advertised as any other TE link.
       The latter can then be used to attract traffic. When an upper
       layer/region LSP tries to make use of this virtual TE link, one
       or more FA LSPs MUST be established using the procedures
       defined in [RFC4206] to make the virtual TE link "real" and
       allow it to carry traffic by nesting the upper layer/region
       LSP.
    
       In order to distinguish usage of such call from the call and
       associated procedures defined in [RFC4974], 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 modeled on the LSP_ATTRIBUTES object defined
       in [RFC5420]. The CALL_ATTRIBUTES object MAY also be used to
       report call operational state on a Notify message.
    
       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.
    
       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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                                                               |
       //                      Call Attributes TLVs                   //
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    
    
    
    
    
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       The Call Attributes TLVs are encoded as described in Section
       5.1.3.
    
    5.1.2 Processing
    
       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.
    
    5.1.3 Call Attributes TLVs
    
       Attributes carried by the CALL_ATTRIBUTES object are encoded
       within TLVs names Call Attributes TLVs. One or more Call
       Attributes TLVs MAY be present in each object.
    
       There are no ordering rules for Call Attributes TLVs, and no
       interpretation SHOULD be placed on the order in which these
       TLVs are received.
    
       Each Call Attributes TLV carried by the CALL_ATTRIBUTES object
       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
    
             Indicates the total length of the TLV in octets. That
             is, the combined length of the Type, Length, and Value
             fields, i.e., four plus the length of the Value field in
             octets.
    
             The entire TLV MUST be padded with between zero and three
             trailing zeros to make it four-octet aligned.  The Length
    
    
    
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             field does not count any padding.
    
          Value
    
             The data field for the TLV padded as described above.
    
       Assignment of Call Attributes TLV types MUST follow the rules
       specified in Section 8 (IANA Considerations).
    
    5.1.4 Call Attributes Flags TLV
    
       The Call Attributes TLV of Type 1 defines the Call Attributes
       Flags TLV. The Call Attributes Flags TLV MAY be present in a
       CALL_ATTRIBUTES object.
    
       The Call 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 MUST therefore always be 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 Call Attribute Flags TLV MUST be assumed to be
       set to zero. If the Call Attribute Flags 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. In
       other terms, assigned bits that are not present either because
       the Call Attribute Flags 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 Call Inheritance Flag at
       position bit 0 (most significant bit) in the Attributes Flags
       TLV. This flag indicates 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 SHALL by default be
       set to 1. Setting this flag to 0 results in a hidden TE link or
       in deleting the corresponding TE link advertisement (by setting
    
    
    
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       the corresponding Opaque LSA Age to MaxAge) if the association
       had been established with this flag set to 1. In the latter
       case, the corresponding FA-LSP SHOULD also be torn down to
       prevent unused resources.
    
       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], [HIER-
       BIS]) and numbered FA-LSPs ([RFC4206], [HIER-BIS]).
    
    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. These are known
         as pre-planned LSPs.
    
       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 [RFC5420]. 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 Attributes Flags TLV,
       follows general processing of [RFC5420] for
       LSP_REQUIRED_ATTRIBUTE 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
    
    
    
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       newly defined attribute requires examination at all transit
       LSRs along the LSP being established.
    
       The Pre-Planned LSP flag can take one of the following values:
    
       o When set to 0 this means that the LSP MUST 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 MUST 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).
    
       Mechanisms for provisioning (pre-planned or not) LSP with 0
       bandwidth is straightforward for PSC LSP: in the SENDER_TSPEC/
       FLOWSPEC object, the Peak Data Rate field of Int-Serv objects
       (see [RFC2210]) MUST be set to 0. For L2SC LSP: the CIR, EIR,
       CBS, and EBS values MUST be set to 0 in the Type 2 sub-TLV of
       the Ethernet Bandwidth Profile TLV. In both cases, upon LSP
       resource commitment, actual traffic parameter values are used
       to perform corresponding resource reservation.
    
       However, mechanisms for provisioning (pre-planned or not) TDM
       or LSC LSP with 0 bandwidth is currently not possible because
       the exchanged label value is tightly coupled with resource
    
    
    
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       allocation during LSP signaling (see e.g. [RFC4606] for
       SDH/SONET LSP). 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, defined as group of LSRs that
       enforces a common TE policy. Thus, the extensions defined in
       this document are expected to run in the context of a
       consistent TE policy. Specification of 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 the method
       selected for 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 a domain is under the
       authority of a single administrative entity. In this context,
       multiple switching layers 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
    
    
    
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       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 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]
    
       Upon approval of this document, IANA is requested to establish
       a "Call attributes TLV" registry. The following types should be
       defined:
    
       TLV Value  Name                                  Reference
       ---------  -------------------------             ---------
       0          Reserved                              [This I-D]
       1          Call Attributes Flags TLV             [This I-D]
    
       The values should be allocated based on the following
       allocation policy as defined in [RFC5226].
    
       Range         Registration Procedures
       -----         ------------------------
       0-32767       RFC
       32768-65535   Private Use
    
       Upon approval of this document, IANA is requested to establish
       a "Call attributes flags" registry. The following flags should
       be defined:
    
    
    
    
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       Bit Number  32-bit Value  Name                   Reference
       ----------  ------------  ---------------------  ---------
       0           0x80000000    Call Inheritance Flag  [This I-D]
    
       The values should be allocated based on the RFC allocation
       policy as defined in [RFC5226].
    
       This document introduces a new Flag in the Attributes Flags
       TLV defined in [RFC5420]:
    
       Bit Number  32-bit Value  Name                   Reference
       ----------  ------------  ---------------------  ---------
       TBD         TBD           Pre-Planned LSP Flag   [This I-D]
    
       This document introduces two new subobjects for the
       EXCLUDE_ROUTE object [RFC4874], C-Type 1.
    
       Subobject Type   Subobject Description
       --------------   ---------------------
       3                Label
       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
       -----  -------------------------------------------------
       25     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
       ----  -------------------------------------------------  ------
       25    Interface Adjustment Capability Descriptor (IACD)  Var.
    
    9. References
    
    9.1 Normative References
    
    
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       [IEEE]     IEEE, "IEEE Standard for Binary Floating-Point
                  Arithmetic", Standard 754-1985, 1985.
    
       [RFC2205]  Braden, R., et al., "Resource ReSerVation Protocol
                  (RSVP) -- Version 1 Functional Specification",
                  RFC 2205, September 1997.
    
       [RFC2210]  Wroclawski, J., "The Use of RSVP with IETF
                  Integrated Services", RFC 2210, September 1997.
    
       [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
                  Requirement Levels", BCP 14, RFC 2119, March 1997.
    
       [RFC2997]  Bernet, Y., Smith, A., and B. Davie, "Specification
                  of the Null Service Type", RFC2997, November 2000.
    
       [RFC3471]  Berger, L., et al., "Generalized Multi-Protocol
                  Label Switching (GMPLS) - Signaling Functional
                  Description", RFC 3471, January 2003.
    
       [RFC3473]  Berger, L., "Generalized Multi-Protocol Label
                  Switching (GMPLS) Signaling Resource ReserVation
                  Protocol-Traffic Engineering (RSVP-TE) Extensions",
                  RFC 3473, January 2003.
    
       [RFC3477]  Kompella, K., and Y. Rekhter, "Signalling Unnumbered
                  Links in Resource ReSerVation Protocol - Traffic
                  Engineering (RSVP-TE)", RFC 3477, January 2003.
    
       [RFC3630]  Katz, D., et al., "Traffic Engineering (TE)
                  Extensions to OSPF Version 2," RFC 3630, September
                  2003.
    
       [RFC3945]  Mannie, E. and al., "Generalized Multi-Protocol
                  Label Switching (GMPLS) Architecture", RFC 3945,
                  October 2004.
    
       [RFC4201]  Kompella, K., et al., "Link Bundling in MPLS Traffic
                  Engineering", RFC 4201, October 2005.
    
       [RFC4202]  Kompella, K., Ed., and Rekhter, Y. Ed., "Routing
                  Extensions in Support of Generalized MPLS", RFC
                  4202, October 2005.
    
       [RFC4203]  Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF
                  Extensions in Support of Generalized Multi-Protocol
                  Label Switching (GMPLS)", RFC 4203, October 2005.
    
    
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       [RFC4206]  Kompella, K., and Rekhter, Y., "LSP Hierarchy with
                  Generalized MPLS TE", RFC4206, October 2005.
    
       [RFC4306]  Kaufman, C., Ed., "Internet Key Exchange (IKEv2)
                  Protocol", RFC 4306, December 2005.
    
       [RFC4606]  Mannie, E., and D. Papadimitriou, D., "Generalized
                  Multi-Protocol Label Switching (GMPLS) Extensions
                  for Synchronous Optical Network (SONET) and
                  Synchronous Digital Hierarchy (SDH) Control,
                  RFC 4606, August 2006.
    
       [RFC5226]  Narten, T., Alvestrand, H., "Guidelines for Writing
                  an IANA Considerations Section in RFCs", BCP 26, RFC
                  5226, May 2008.
    
       [RFC5305]  Smit, H. and T. Li, "Intermediate System to
                  Intermediate System (IS-IS) Extensions for Traffic
                  Engineering (TE)", RFC 5305, October 2008.
    
       [RFC5307]  Kompella, K., Ed., and Y. Rekhter, Ed.,
                  "Intermediate System to Intermediate System (IS-IS)
                  Extensions in Support of Generalized Multi-Protocol
                  Label Switching (GMPLS)", RFC 5307, October 2005.
    
       [RFC5420]  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 5420,
                  February 2009.
    
       [RFC4874]  Lee, C.Y., et al. "Exclude Routes - Extension to
                  RSVP-TE," RFC 4874, April 2007.
    
       [RFC4974]  Papadimitriou, D., and Farrel, A., "Generalized MPLS
                  (GMPLS) RSVP-TE Signaling Extensions in support of
                  Calls," RFC 4974, August 2007.
    
    9.2 Informative References
    
       [GMPLS-RR]  Berger, L., Papadimitriou, D., and JP. Vasseur,
                   "PathErr Message Triggered MPLS and GMPLS LSP
                   Reroute", RFC 5710, January 2010.
    
    
    
    
    
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       [HIER-BIS]  Shiomoto, K., and Farrel, A., "Procedures for
                   Dynamically Signaled Hierarchical Label Switched
                   Paths", draft-ietf-ccamp-lsp-hierarchy-bis, Work in
                   progress.
    
       [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.
    
       [MPLS-SEC]  Fang, L. Ed., "Security Framework for MPLS and
                   GMPLS Networks", draft-ietf-mpls-mpls-and-gmpls-
                   security-framework, Work in progress.
    
       [RFC5212]   Shiomoto, K., et al., "Requirements for GMPLS-based
                   multi-region and multi-layer networks (MRN/MLN)",
                   RFC 5212, July 2008.
    
       [RFC5339]   Leroux, J.-L., et al., "Evaluation of existing
                   GMPLS Protocols against Multi Region and Multi
                   Layer Networks (MRN/MLN)", RFC 5339, September
                   2008.
    
    Acknowledgments
    
       The authors would like to thank Mr. Wataru Imajuku for the
       discussions on adjustment between regions.
    
    Author's Addresses
    
       Dimitri Papadimitriou
       Alcatel-Lucent
       Copernicuslaan 50
       B-2018 Antwerpen, Belgium
       Phone: +32 3 2408491
       Email: dimitri.papadimitriou@alcatel-lucent.com
    
       Martin Vigoureux
       Alcatel-Lucent
       Route de Villejust
       91620 Nozay, France
       Phone: +33 1 30772669
       Email: martin.vigoureux@alcatel-lucent.fr
    
       Kohei Shiomoto
       NTT
    
    
    
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       3-9-11 Midori-cho
       Musashino-shi, Tokyo 180-8585, Japan
       Phone: +81 422 594402
       Email: shiomoto.kohei@lab.ntt.co.jp
    
       Deborah Brungard
       ATT
       Rm. D1-3C22 - 200 S. Laurel Ave.
       Middletown, NJ 07748, USA
       Phone: +1 732 4201573
       Email: dbrungard@att.com
    
       Jean-Louis Le Roux
       France Telecom
       Avenue Pierre Marzin
       22300 Lannion, France
       Phone: +33 2 96053020
       Email: jean-louis.leroux@rd.francetelecom.com
    
    Contributors
    
       Eiji Oki
       University of Electro-Communications
       1-5-1 Chofugaoka
       Chofu, Tokyo 182-8585, Japan
       Email: oki@ice.uec.ac.jp
    
       Ichiro Inoue
       NTT Network Service Systems Laboratories
       3-9-11 Midori-cho
       Musashino-shi, Tokyo 180-8585, Japan
       Phone : +81 422 596076
       Email: ichiro.inoue@lab.ntt.co.jp
    
       Emmanuel Dotaro
       Alcatel-Lucent France
       Route de Villejust
       91620 Nozay, France
       Phone : +33 1 69634723
       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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