[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits] [IPR]

Versions: 00 01 02 03 draft-ietf-pce-remote-initiated-gmpls-lsp

     PCE Working Group                                         Zafar Ali
     Internet Draft                                       Siva Sivabalan
     Intended status: Standard Track                   Clarence Filsfils
     Expires: January 14, 2014                             Cisco Systems
   
                                                            Robert Varga
                                                   Pantheon Technologies
   
                                                            Victor Lopez
                                                  Oscar Gonzalez de Dios
                                                          Telefonica I+D
   
                                                           July 15, 2013
   
   
             Path Computation Element Communication Protocol (PCEP)
                Extensions for remote-initiated GMPLS LSP Setup
                draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
   
   Status of this Memo
   
   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.
   
   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.
   
   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."
   
   This Internet-Draft will expire on January 13, 2014.
   
   Copyright Notice
   
   Copyright (c) 2013 IETF Trust and the persons identified as the
   document authors.  All rights reserved.
   
   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.
   
     Expires January 2014                                      [Page 1]


     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
     Abstract
   
     PCEP Extensions for PCE-initiated LSP Setup in a Stateful PCE Model
     draft [I-D. draft-crabbe-pce-pce-initiated-lsp] specifies
     procedures that can be used for creation and deletion of PCE-
     initiated LSPs under the active stateful PCE model. However, this
     specification is focused on MPLS networks, and does not cover
     remote instantiation of GMPLS paths.  This document complements
     PCEP Extensions for PCE-initiated LSP Setup in a Stateful PCE Model
     draft by addressing the extensions required for GMPLS applications,
     for example for OTN and WSON networks.
   
     When active stateful PCE is used for managing PCE-initiated LSP,
     PCC may not be aware of the intended usage of the LSP (e.g., in a
     multi-layer network). PCEP Extensions for PCE-initiated LSP Setup
     in a Stateful PCE Model draft does not address this requirement.
     This draft also addresses the requirement to specify on how PCC
     should use the PCEP initiated LSPs.
   
   
     Conventions used in this document
   
     The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
     "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in
     this document are to be interpreted as described in RFC 2119
     [RFC2119].
   
     Table of Contents
   
        1. Introduction...................................................3
        2. Use Cases..................................................... 4
          2.1. Single-layer provisioning from Active stateful PCE........ 4
          2.2. Bandwidth-on-demand for multi-layer networks.............. 5
          2.3. Higher-layer signaling trigger............................ 6
          2.4. NMS-VNTM cooperation model (separated flavor)............. 8
                          Expires January 2014                  [Page 2]


     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
        3. GMPLS Requirements for Remote-Initiated LSPs.................. 9
        4. Remote Initiated LSP Usage Requirement....................... 10
        5. PCEP Extensions for Remote-Initiated GMPLS LSPs.............. 10
          5.1. Generalized Endpoint in LSP Create Message............... 11
          5.2. GENERALIZED-BANDWIDTH object in LSP Create Message....... 11
          5.3. Protection Attributes in LSP Create Message.............. 12
          5.4. ERO in LSP Create Object................................. 12
              5.4.1. ERO with explicit label control.................... 12
              5.4.2. ERO with Path Keys................................. 13
              5.4.3. Switch Layer Object ................................13
        6. PCEP extension for PCEP Initiated LSP Usage Specification.... 14
          6.1. LSP_TUNNEL_INTERFACE_ID Object in LSP Create Message..... 14
          6.2. Communicating LSP usage to Egress node................... 15
          6.3. LSP delegation and cleanup ...............................16
        7. Security Considerations...................................... 16
        8. IANA Considerations.......................................... 16
          8.1. END-POINT Object......................................... 16
          8.2. PCEP-Error Object........................................ 16
        9. Acknowledgments.............................................. 16
        10. References.................................................. 16
          10.1. Normative References.................................... 16
          10.2. Informative References.................................. 17
   
     1. Introduction
   
        The Path Computation Element communication Protocol (PCEP)
        provides mechanisms for Path Computation Elements (PCEs) to
        perform route computations in response to Path Computation
        Clients (PCCs) requests. PCEP Extensions for PCE-initiated LSP
        Setup in a Stateful PCE Model draft [I-D. draft-ietf-pce-
        stateful-pce] describes a set of extensions to PCEP to enable
        active control of MPLS-TE and GMPLS tunnels.
   
        [I-D. draft-crabbe-pce-pce-initiated-lsp] describes the setup
        and teardown of PCE-initiated LSPs under the active stateful PCE
        model, without the need for local configuration on the PCC, thus
        allowing for a dynamic network that is centrally controlled and
        deployed. However, this specification is focused on MPLS
        networks, and does not cover the GMPLS networks (e.g., WSON,
        OTN, SONET/ SDH, etc. technologies). GMPLS requirements for PCEP
        initiated LSPs are outlined in Section 3. This document
        complements [I-D. draft-crabbe-pce-pce-initiated-lsp] by
        addressing the requirements for remote-initiated GMPLS LSPs. The
        PCEP extensions for PCEP initiated GMPLS LSPs are specified in
        Section 5. The mechanism described in this document is
        applicable not only to active PCEs initiating LSPs, but to any
        entity that initiates LSPs remotely.
   
                          Expires January 2014                  [Page 3]


     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
        When an active stateful PCE is used for managing remote-
        initiated LSP, the PCC may not be aware of the intended usage of
        the remote-initiated LSP. For example, the PCC may not know the
        target IGP instance in which the remote-initiated LSP is to be
        used. These requirements are outlined in Section 4. [RFC6107]
        defines LSP_TUNNEL_INTERFACE_ID Object for communicating target
        IGP instance and usage of the forwarding and/ or routing
        adjacency from the ingress node to the egress node. However,
        current PCEP specifications do not include signaling of the
        LSP_TUNNEL_INTERFACE_ID TLV in the PCEP message. Furthermore,
        [I-D. draft-crabbe-pce-pce-initiated-lsp] does not address this
        requirement. This draft also addresses the requirement to
        specify on how PCC should use the PCEP initiated LSPs. This is
        achieved by using LSP_TUNNEL_INTERFACE_ID Object defined in
        [RFC6107] in PCEP, as detailed in Section 6.
   
     2. Use Cases
   
     2.1. Single-layer provisioning from active stateful PCE
   
        Figure 1 shows a single-layer topology with optical nodes with a
        GMPLS control plane. In this scenario, the active PCE can
        dynamically create or delete L0 services between client
        interfaces. This process can be triggered by the deployment of a
        new network configuration or a re-optimization process. This
        operation can be human-driven (e.g. through an NMS) or an
        automatic process.
   
   
   
   
        [Please refer to pdf version for the Figure]
   
   
        Figure 1. Single-layer provisioning from active stateful PCE.
   
   
   
                          Expires January 2014                  [Page 4]


     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
        L0 PCE obtains resources information via control plane
        collecting LSAs messages. The request contains, at least, two
        optical transport interfaces (OT i/f), so PCE computes the path
        and sends a message to the optical equipment with ERO path
        information.
   
   
   
     2.2. Bandwidth-on-demand for multi-layer networks
   
        This use case assumes there is a multi-layer network composed by
        routers and optical equipment. In this scenario, there is an
        entity, which decides it needs extra bandwidth between two
        routers. This certain moment a GMPLS LSP connecting both routers
        via the optical network can be established on-the-fly. This
        entity can be a router, an active stateful PCE or even the NMS
        (with or without human intervention).
   
        It is important to note that the bandwidth-on-demand interfaces
        and spare bandwidth in the optical network could be shared to
        cover many under capacity scenarios in the L3 network. For
        example, in this use-case, if we assume all interfaces are 10G
        and there is 10G of spare bandwidth available in the optical
        network, the spare bandwidth in the optical network can be used
        to connect any router, depending on bandwidth demand of the
        router network. For example, if there are three routers, it is
        not known a priori if the demand will make bandwidth-on-demand
        interface at R1 to be connected to bandwidth-on-demand interface
        at R2 or R3. For this reason, bandwidth-on-demand interfaces
        cannot be pre-provisioned with the IP services that are expected
        to carry.
   
        According to [RFC5623], there are four options of Inter-Layer
        Path Computation and Inter-Layer Path Control Models: (1) PCE-
        VNTM cooperation, (2) Higher-layer signaling trigger, (3) NMS-
        VNTM cooperation model (integrated flavor) and (4) NMS-VNTM
        cooperation model (separated flavor). In all scenarios there is
        a certain moment when entities are using an interface to request
        for a path provisioning. In this document we have selected two
        use cases in a scenario with routers and optical equipment to
        obtain the requirements for this draft, but it is applicable to
        the four options.
   
   
        [Please refer to pdf version for the Figure]
   
        Figure 2. Use case higher-layer signaling trigger
   
                          Expires January 2014                  [Page 5]


     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
     2.3. Higher-layer signaling trigger
   
        Figure 2 depicts a multi-layer network scenario similar to the
        presented in section 4.2.2. [RFC5623], with the difference that
        PCE is an active stateful PCE [I-D. draft-ietf-pce-stateful-
        pce].
   
        In this example, O1, O2 and O3 are optical nodes that are
        connected with router nodes R1, R2 and R3, respectively. The
        network is designed such that the interface between R1-O1, R2-O2
        and R3-O3 are setup to provide bandwidth-on-demand via the
        optical network.
   
   
                          Expires January 2014                  [Page 6]


     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
        The example assumes that an active stateful PCE is used for
        setting and tearing down bandwidth-on-demand connectivity.
        Although the simple use-case assumes a single PCE server (PCE1),
        the proposed technique is generalized to cover multiple co-
        operating PCE case. Similarly, although the use case assumes
        PCE1 only has knowledge of the L3 topology, the proposed
        technique is generalized to cover multi-layer PCE case.
   
        The PCE server (PCE1) is assumed to be receiving L3 topology
        data. It is also assumed that PCE learns L0 (optical) addresses
        associated with bandwidth-on-demand interfaces R1-O1, R2-O2 and
        R3-O3. These addresses are referred by OTE-IP-R1 (optical TE
        link R1-O1 address at R1), OTE-IP-R2 (optical TE link R2-O2
        address at R2) and OTE-IP-R3 (optical TE link R3-O3 address at
        R3), respectively. How PCE learns the optical addresses
        associated with the bandwidth-on-demand interfaces is beyond the
        scope of this document.
   
        How knowledge of the bandwidth-on-demand interfaces is utilized
        by the PCE is exemplified in the following. Suppose an
        application requests 8 Gbps from R1 to R2 (recall all interfaces
        in Figure 1 are assumed to be 10G). PCE1 satisfies this by
        establishing a tunnel using R1-R4-R2 path. PCEP initiated LSP
        using techniques specified in [I-D. draft-crabbe-pce-pce-
        initiated-lsp] can be used to establish a PSC tunnel using the
        R1-R4-R2 path. Now assume another application requests 7 Gbps
        service between R1 and R2. This request cannot be satisfied
        without establishing a GMPLS tunnel via optical network using
        bandwidth-on-demand interfaces. In this case, PCE1 initiates a
        GMPLS tunnel using R1-O1-O2-R2 path (this is referred as GMPLS
        tunnel1 in the following). The PCEP initiated LSP using
        techniques specified in document are used for this purpose.
   
        As mentioned earlier, the GMPLS tunnel created on-the-fly to
        satisfy bandwidth demand of L3 applications cannot be pre-
        provisioned in IP network, as bandwidth-on-demand interfaces and
        spare bandwidth in the optical network are shared. Furthermore,
        in this example, as active stateful PCE is used for managing
        PCE-initiated LSP, PCC may not be aware of the intended usage of
        the PCE-initiated LSP. Specifically, when the PCE1 initiated
        GMPLS tunnel1, PCC does not know the IGP instance whose demand
        leads to establishment of the GMPLS tunnel1 and hence does not
        know the IGP instance in which the GMPLS tunnel1 needs to be
        advertised. Similarly, the PCC does not know IP address that
        should be assigned to the GMPLS tunnel1. In the above example,
        this IP address is labeled as TUN-IP-R1 (tunnel IP address at
        R1). The PCC also does not know if the tunnel needs to be
        advertised as forwarding and/ or routing adjacency and/or to be
        locally used by the target IGP instance. Similarly, egress node
        for GMPLS signaling (R2 node in this example) may not know the
        intended usage of the tunnel (tunnel1 in this example). For
        example, the R2 node does not know IP address that should be
                          Expires January 2014                  [Page 7]


     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
        assigned to the GMPLS tunnel1. In the above example, this IP
        address is labeled as TUN-IP-R2 (tunnel IP address at R2).
        Section 6 of this draft addresses the requirement to specify on
        how PCC and egress node for signaling should use the PCEP
        initiated LSPs.
   
     2.4. NMS-VNTM cooperation model (separated flavor)
   
        Figure 3 depicts NMS-VNTM cooperation model. This is the
        separated flavor, because NMS and VNTM are not in the same
        location.
   
        A new L3 path is requested from NMS, because there is an
        automated process in the NMS or after human intervention. NMS
        does not have information about all network information, so it
        consults L3 PCE. For shake of simplicity L3-PCE is used, but any
        other multi-layer cooperating PCE model is applicable. In case
        that there are enough resources in the L3 layer, L3-PCE returns
        a L3 only path. On the other hand, if there is a lack of
        resources at the L3 layer, the response does not have any path
        or may contain a multilayer path with L3 and L0 (optical)
        information in case of a ML-PCE. In case of there is not a path
        in L3; NMS sends a message to the VNTM to create a GMPLS LSP in
        the lower layer. When the VNTM receives this message, based on
        the local policies, accepts the suggestion and sends a similar
        message to the router, which can create the lower layer LSP via
        UNI signaling in the routers, like in use case in section 2.3.1.
        Similarly, VNTM may talk with L0-PCE to set-up the path in the
        optical domain (section 2.2). This second option looks more
        complex, because it requires VNTM configuring inter-layer TE-
        links.
   
        Requirements for the message from VNTM to the router are the
        same than in the previous use case (section 2.3.1). Regarding
        NMS to VNTM message, the requirements here depends on who has
        all the information. Three different addresses are required in
        this use case: (1) L3, (2) L0 and (3) inter-layer addressing. In
        case there is a non-cooperating L3-PCE, information about inter-
        layer connections have to be stored (or discovered) by VNTM. If
        there is a ML-PCE and this information is obtained from the
        network, the message would be the same than in section 2.3.1.
   
   
        [Please refer to pdf version for the Figure]
   
        Figure 3. Use case NMS-VNTM cooperation model
   
   
   
   
   
   
   
   
   
   
   
                          Expires January 2014                  [Page 8]


     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
   
     3. GMPLS Requirements for Remote-Initiated LSPs
   
        [I-D. draft-crabbe-pce-pce-initiated-lsp] specifies procedures
        that can be used for creation and deletion of PCE-initiated LSPs
        under the active stateful PCE model. However, this specification
        does not address GMPLS requirements outlined in the following:
   
        - GMPLS support multiple switching capabilities on per TE link
          basis. GMPLS LSP creation requires knowledge of LSP switching
          capability (e.g., TDM, L2SC, OTN-TDM, LSC, etc.) to be used
          [RFC3471], [RFC3473].
   
        - GMPLS LSP creation requires knowledge of the encoding type
          (e.g., lambda photonic, Ethernet, SONET/ SDH, G709 OTN, etc.)
          to be used by the LSP [RFC3471], [RFC3473].
   
        - GMPLS LSP creation requires information of the generalized
          payload (G-PID) to be carried by the LSP [RFC3471],
          [RFC3473].
   
   
                          Expires January 2014                  [Page 9]

  Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
        - GMPLS LSP creation requires specification of data flow
          specific traffic parameters (also known as Tspec), which are
          technology specific.
   
        - GMPLS also specifics support for asymmetric bandwidth
          requests [RFC6387].
   
        - GMPLS extends the addressing to include unnumbered interface
          identifiers, as defined in [RFC3477].
   
        - In some technologies path calculation is tightly coupled with
          label selection along the route. For example, path
          calculation in a WDM network may include lambda continuity
          and/ or lambda feasibility constraints and hence a path
          computed by the PCE is associated with a specific lambda
          (label). Hence, in such networks, the label information needs
          to be provided to a PCC in order for a PCE to initiate GMPLS
          LSPs under the active stateful PCE model. I.e., explicit
          label control may be required.
   
        - GMPLS specifics protection context for the LSP, as defined in
          [RFC4872] and [RFC4873].
   
     4. Remote Initiated LSP Usage Requirement
   
        The requirement to specify usage of the LSP to the PCC includes
        but not limited to specification of the following information.
   
        - The target IGP instance for the Remote-initiated LSP needs to
          be specified.
   
        - In the target IGP instance, should the PCE-initiated LSP be
          advertised as a forwarding adjacency and/ or routing
          adjacency and/ or to be used locally by the PCC?
   
        - Should the as Remote-initiated LSP be advertised an IPv4 FA/
          RA, IPv6 FA/ RA or as unnumbered FA/ RA.
   
        - If Remote-initiated LSP is to be advertised an IPv4 FA/ RA,
          IPv6 FA/ RA, what is the local and remote IP address is to be
          used for the advertisement.
   
     5. PCEP Extensions for Remote-Initiated GMPLS LSPs
   
        Section 3 outlines GMPLS and application requirements that need
        to be satisfied in order for a PCE to initiate GMPLS LSPs under
        the active stateful PCE model. The section provides PCEP
        protocol extensions required to meet these requirements.
   
   
   
                          Expires January 2014                  [Page
     10] 

   
   
   
   
   
     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
        LSP create message defined in [I-D. draft-crabbe-pce-pce-
        initiated-lsp] needs to be extended to include GMPLS specific
        PCEP objects as follows:
   
     5.1. Generalized Endpoint in LSP Create Message
   
        This document does not modify the usage of END-POINTS object for
        PCE initiated LSPs as specified in [I-D. draft-crabbe-pce-pce-
        initiated-lsp]. It augments the usage as specified below.
   
        END-POINTS object has been extended by [I-D. draft-ietf-pcep-
        gmpls-ext] to include a new object type called ''Generalized
        Endpoint''. PCCreate message sent by a PCE to a PCC to trigger a
        GMPLS LSP instantiation SHOULD include the END-POINTS with
        Generalized Endpoint object type. Furthermore, the END-POINTS
        object MUST contain ''label request'' TLV. The label request TLV
        is used to specify the switching type, encoding type and GPID of
        the LSP being instantiated by the PCE.
   
        As mentioned earlier, the PCE server is assumed to be receiving
        topology data. In the use case of higher-layer signaling
        trigger, the addresses associated with bandwidth-on-demand
        interfaces are included, e.g., OTE-IP-R1, OTE-IP-R2 and OTE-IP-
        R3, in the use case example. These addresses and R1, R2 and R3
        router IDs are used to derive source and destination address of
        the END-POINT object. As previously mentioned, in the case of
        NMS-VNMT cooperation model with L3 PCE, VNTM must receive such
        inter-layer interface association to configure the whole path.
   
        The unnumbered endpoint TLV can be used to specify unnumbered
        endpoint addresses for the LSP being instantiated by the PCE.
        The END-POINTS MAY contain other TLVs defined in [I-D. draft-
        ietf-pcep-gmpls-ext].
   
        If the END-POINTS Object of type Generalized Endpoint is missing
        the label request TLV, the PCC MUST send a PCErr message with
        Error-type=6 (Mandatory Object missing) and Error-value= TBA
        (LSP request TLV missing).
   
        If the PCC does not support the END-POINTS Object of type
        Generalized Endpoint, the PCC MUST send a PCErr message with
        Error-type= ???? and Error-value= ???. [??? = already defined
        values to be looked up].
   
     5.2. GENERALIZED-BANDWIDTH object in LSP Create Message
   
           LSP create message defined in [I-D. draft-crabbe-pce-pce-
        initiated-lsp] can optionally include the BANDWIDTH object.
        However, the following possibilities cannot be represented in
        the BANDWIDTH object:
   
                          Expires January 2014                  [Page
     11] 

   
   
   
   
   
     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
           - Asymmetric bandwidth (different bandwidth in forward and
        reverse direction), as described in [RFC6387].
   
           - Technology specific GMPLS parameters (e.g., Tspec for
        SDH/SONET, G.709, ATM, MEF, etc.) are not supported.
   
        GENERALIZED-BANDWIDTH object has been defined in [I-D. draft-
        ietf-pcep-gmpls-ext] to address the above-mentioned limitation
        of the BANDWIDTH object.
   
        This document specifies the use of GENERALIZED-BANDWIDTH object
        in PCCreate message. Specifically, GENERALIZED-BANDWIDTH object
        MAY be included in the PCCreate message. The GENERALIZED-
        BANDWIDTH object in PCCreate message is used to specify
        technology specific Tspec and asymmetrical bandwidth values for
        the LSP being instantiated by the PCE.
   
     5.3. Protection Attributes in LSP Create Message
   
        This document does not modify the usage of LSPA object for PCE
        initiated LSPs as specified in [I-D. draft-crabbe-pce-pce-
        initiated-lsp]. It augments the usage of LSPA object in LSP
        Create Message to carry the end-to-end protection context this
        also includes the protection state information.
   
        The LSP Protection Information TLV of LSPA in the PCCreate
        message can be used to specify protection attributes of the LSP
        being instantiated by the PCE.
   
     5.4. ERO in LSP Create Object
   
        This document does not modify the usage of ERO object for PCE
        initiated LSPs as specified in [I-D. draft-crabbe-pce-pce-
        initiated-lsp]. It augments the usage as specified in the
        following sections.
   
     5.4.1. ERO with explicit label control
   
        As mentioned earlier, there are technologies and scenarios where
        active stateful PCE requires explicit label control in order to
        instantiate an LSP.
   
        Explicit label control (ELC) is a procedure supported by RSVP-
        TE, where the outgoing label(s) is (are) encoded in the ERO. [I-
        D. draft-ietf-pcep-gmpls-ext] extends the <ERO> object of PCEP
        to include explicit label control. The ELC procedure enables the
        PCE to provide such label(s) directly in the path ERO.
   
        The extended ERO object in PCCreate message can be used to
        specify label along with ERO to PCC for the LSP being
        instantiated by the active stateful PCE.
                          Expires January 2014                  [Page
     12] 

   
   
   
   
   
     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
     5.4.2. ERO with Path Keys
   
        There are many scenarios in packet and optical networks where
        the route information of an LSP may not be provided to the PCC
        for confidentiality reasons.  A multi-domain or multi-layer
        network is an example of such networks. Similarly, a GMPLS User-
        Network Interface (UNI) [RFC4208] is also an example of such
        networks.
   
        In such scenarios, ERO containing the entire route cannot be
        provided to PCC (by PCE). Instead, PCE provides an ERO with Path
        Keys to the PCC. For example, in the case UNI interface between
        the router and the optical nodes, the ERO in the LSP Create
        Message may be constructed as follows:
   
       - The first hop is a strict hop that provides the egress
          interface information at PCC. This interface information is
          used to get to a network node that can extend the rest of the
          ERO. (Please note that in the cases where the network node is
          not directly connected with the PCC, this part of ERO may
          consist of multiple hops and may be loose).
       - The following(s) hop in the ERO may provide the network node
          with the path key [RFC5520] that can be resolved to get the
          contents of the route towards the destination.
       - There may be further hops but these hops may also be encoded
          with the path keys (if needed).
   
       This document does not change encoding or processing roles for
       the path keys, which are defined in [RFC5520].
   
   
   
     5.4.3. Switch Layer Object
   
        [draft-ietf-pce-inter-layer-ext-07] specifies the SWITCH-LAYER
        object which defines and specifies the switching layer (or
        layers) in which a path MUST or MUST NOT be established. A
        switching layer is expressed as a switching type and encoding
        type. [I-D. draft-ietf-pcep-gmpls-ext], which defines the GMPLS
        extensions for PCEP, suggests using the SWITCH-LAYER object.
        Thus, SWITCH-LAYER object can be used in the PCCreate message to
        specify the switching layer (or layers) of the LSP being
        remotely initiated.
   
   
   
   
                          Expires January 2014                  [Page
     13] 

   
   
   
   
   
     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
     6. PCEP extension for PCEP Initiated LSP Usage Specification
   
        The requirement to specify on how PCC should use the PCEP
        initiated LSPs in outlined in Section 4. This subsection
        specifies PCEP extension used to satisfy this requirement.
   
        PCEP extensions specified in this section are equally applicable
        to PCEP initiated MPLS as well as GMPLS LSPs.
   
     6.1. LSP_TUNNEL_INTERFACE_ID Object in LSP Create Message
   
        [RFC6107] defines LSP_TUNNEL_INTERFACE_ID Object for
        communicating usage of the forwarding or routing adjacency from
        the ingress node to the egress node. This document extends the
        LSP Create Message to include LSP_TUNNEL_INTERFACE_ID object
        defined in [RFC6107]. Object class and type for the
        LSP_TUNNEL_INTERFACE_ID object are as follows:
   
        Object Name: LSP_TUNNEL_INTERFACE_ID
   
        Object-Class Value: TBA by Iana (suggested value: 40)
   
        Object-type: 1
   
        The contents of this object are identical in encoding to the
        contents of the RSVP-TE LSP_TUNNEL_INTERFACE_ID object defined
        in [RFC6107] and [RFC3477]. The following TLVs of RSVP-TE
        LSP_TUNNEL_INTERFACE_ID object are acceptable in this object.
        The PCEP LSP_TUNNEL_INTERFACE_ID object's TLV types correspond
        to RSVP-TE LSP_TUNNEL_INTERFACE_ID object's TLV types. Please
        note that use of TLV type 1 defined in [RFC3477] is not
        specified by this document.
   
        TLV   TLV
        Type  Description                                     Reference
        --  ------------------------------------------------- ----------
        2  IPv4 interface identifier with target IGP instance [RFC6107]
   
        3  IPv6 interface identifier with target IGP instance [RFC6107]
   
        4  Unnumbered interface with target IGP instance
           [RFC6107]
   
        The meanings of the fields of PCEP LSP_TUNNEL_INTERFACE_ID
        object are identical to those defined for the RSVP-TE
        LSP_TUNNEL_INTERFACE_ID object. Similarly, meanings of the
        fields of PCEP LSP_TUNNEL_INTERFACE_ID object's supported TLV
        are identical to those defined for the corresponding RSVP-TE
        LSP_TUNNEL_INTERFACE_ID object's TLVs. The following fields have
        slightly different usage.
   
                          Expires January 2014                  [Page
     14] 

   
   
   
   
   
     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
       - IPv4 Interface Address field in IPv4 interface identifier with
          target IGP instance TLV: This field indicates the local IPv4
          address to be assigned to the tunnel at the PCC (ingress node
          for RSVP-TE signaling). In the example use case of Section 2,
          IP address TUN-IP-R1 (tunnel IP address at R1) is carried in
          this field (if TUN-IP-R1 is a v4 address).
   
       - IPv6 Interface Address field in IPv4 interface identifier with
          target IGP instance TLV: This field indicates the local IPv6
          address to be assigned to the tunnel at the PCC (ingress node
          for RSVP-TE signaling). In the example use case of Section 2,
          IP address TUN-IP-R1 (tunnel IP address at R1) is carried in
          this field (if TUN-IP-R1 is a v6 address).
   
       - LSR's Router ID field in Unnumbered interface with target IGP
          instance: The PCC SHOULD use the LSR's Router ID in Unnumbered
          interface with target IGP instance in advertising the LSP
          being initiated by the PCE. In the example use case of Section
          2, this field carries router-id of R1 in the target IGP
          instance.
   
       - Interface ID (32 bits) field in unnumbered interface with
          target IGP instance: All bits of this field MUST be set to 0
          by the PCE server and MUST be ignored by PCC. PCC SHOULD
          allocate an Interface ID that fulfills Interface ID
          requirements specified in [RFC3477].
   
        When the Ingress PCC receives an LPS Request Message with
        LSP_TUNNEL_INTERFACE_ID TLV, it uses the information contained
        in the TLV to drive the IGP instance, treatment of the LSP being
        initiated in the target IGP instance (e.g., FA, RA or local
        usage), the local IPv4 or IPv6 address or router-id for
        unnumbered case to be used for advertisement of the LSP being
        instantiated.
   
     6.2. Communicating LSP usage to Egress node
   
        PCE does not need to send LSP Create message to egress node
        (node R2 in the example of section 2) to communicate LSP usage
        information. Instead PCC (Ingres signaling node) uses RSVP-TE
        signaling mechanism specified in [RFC6107] to send the LSP usage
        to Egress node. Specifically, when the Ingress PCC receives an
        LPS Request Message with LSP_TUNNEL_INTERFACE_ID TLV, it SHOULD
        add LSP_TUNNEL_INTERFACE_ID object in RSVP TE Path message. For
        this purpose, it is RECOMMENDED that the ingress PCC uses
        content of the LSP_TUNNEL_INTERFACE_ID TLV in LSP Create Message
        in PCEP to drive LSP_TUNNEL_INTERFACE_ID object in RSVP-TE. This
        document does not modify usage of LSP_TUNNEL_INTERFACE_ID Object
        in RSVP-TE signaling as specified in [RFC6107].
   
   
                          Expires January 2014                  [Page
     15] 

   
   
   
   
   
     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
        The egress node uses information contained in the
        LSP_TUNNEL_INTERFACE_ID object in RSVP-TE Path message to drive
        the IGP instance, treatment of the LSP being initiated in the
        target IGP instance (e.g., FA, RA or local usage), the local
        IPv4 or IPv6 address or router-id for unnumbered case to be used
        for advertisement of the LSP being instantiated.
   
     6.3. LSP delegation and cleanup
   
        LSP delegation and cleanup procedure specified in [I-D. draft-
        ietf-pcep-gmpls-ext] are equally applicable to GMPLS LSPs and
        this document does not modify the associated usage.
   
     7. Security Considerations
   
        To be added in future revision of this document.
   
     8. IANA Considerations
   
     8.1. END-POINT Object
   
        This document extends the LSP Create Message to include
        LSP_TUNNEL_INTERFACE_ID object defined in [RFC6107]. Object
        class and type for the LSP_TUNNEL_INTERFACE_ID object are as
        follows:
   
        Name                       Class value                      Type
        ----                       -----------                      ----
        LSP_TUNNEL_INTERFACE_ID    TBA by Iana (Suggested:40)        1
   
     8.2. PCEP-Error Object
   
        This document defines the following new Error-Value:
   
        Error-Type  Error Value
   
        6           Error-value=TBA:  LSP Request TLV missing
   
     9. Acknowledgments
   
        The authors would like to thank George Swallow and Jan Medved
        for their comments.
   
     10. References
   
   
     10.1. Normative References
   
         [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
                  Requirement Levels", BCP 14, RFC 2119, March 1997.
                          Expires January 2014                  [Page
     16] 

   
   
   
   
   
     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
         [I-D. draft-crabbe-pce-pce-initiated-lsp] Crabbe, E., Minei,
                  I., Sivabalan, S., Varga, R., ''PCEP Extensions for
                  PCE-initiated LSP Setup in a Stateful PCE Model'',
                  draft-crabbe-pce-pce-initiated-lsp, work in progress.
   
         [RFC5440]  Vasseur, JP., Ed., and JL. Le Roux, Ed., "Path
                  Computation Element (PCE) Communication Protocol
                  (PCEP)", RFC 5440, March 2009.
   
         [RFC5623] Oki, E., Takeda, T., Le Roux, JL., and A. Farrel,
                  "Framework for PCE-Based Inter-Layer MPLS and GMPLS
                  Traffic Engineering", RFC 5623, September 2009.
   
        [RFC 6107] Shiomoto, K., Ed., and A. Farrel, Ed., "Procedures
                  for Dynamically Signaled Hierarchical Label Switched
                  Paths", RFC 6107, February 2011.
   
     10.2. Informative References
   
         [RFC3471] Berger, L., Ed., "Generalized Multi-Protocol Label
                  Switching (GMPLS) Signaling Functional Description",
                  RFC 3471, January 2003.
   
        [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label
                  Switching (GMPLS) Signaling Resource ReserVation
                  Protocol-Traffic Engineering (RSVP-TE) Extensions",
                  RFC 3473, January 2003.
   
        [RFC 5467] Berger, L., Takacs, A., Caviglia, D., Fedyk, D., and
                  J. Meuric, "GMPLS Asymmetric Bandwidth Bidirectional
                  Label Switched Paths (LSPs)", RFC 5467, March 2009.
   
   
   
        [RFC3477] Kompella, K. and Y. Rekhter, "Signalling Unnumbered
                  Links in Resource ReSerVation Protocol - Traffic
                  Engineering (RSVP-TE)", RFC 3477, January 2003.
   
   
        [RFC4872] Lang, J., Ed., Rekhter, Y., Ed., and D. Papadimitriou,
                  Ed., "RSVP-TE Extensions in Support of End-to-End
                  Generalized Multi-Protocol Label Switching (GMPLS)
                  Recovery", RFC 4872, May 2007.
   
        [RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A.
                  Farrel, "GMPLS Segment Recovery", RFC 4873, May 2007.
   
   
   
   
   
                          Expires January 2014                  [Page
     17] 

   
   
   
   
   
     Internet-Draft    draft-ali-pce-remote-initiated-gmpls-lsp-01.txt
   
        [RFC4208] Swallow, G., Drake, J., Ishimatsu, H., and Y. Rekhter,
                  "Generalized Multiprotocol Label Switching (GMPLS)
                  User-Network Interface (UNI): Resource ReserVation
                  Protocol-Traffic Engineering (RSVP-TE) Support for the
                  Overlay Model", RFC 4208, October 2005.
   
   
   
        [RFC5520] Bradford, R., Ed., Vasseur, JP., and A. Farrel,
                  "Preserving Topology Confidentiality in Inter-Domain
                  Path Computation Using a Path-Key-Based Mechanism",
                  RFC 5520, April 2009.
   
   
   
   
   
     Authors' Addresses
   
   
        Zafar Ali
        Cisco Systems
        Email: zali@cisco.com
   
        Siva Sivabalan
        Cisco Systems
        Email: msiva@cisco.com
   
        Clarence Filsfils
        Cisco Systems
        Email: cfilsfil@cisco.com
   
   
        Robert Varga
        Pantheon Technologies
   
        Victor Lopez
        Telefonica I+D
        Email: vlopez@tid.es
   
        Oscar Gonzalez de Dios
        Telefonica I+D
        Email: ogondio@tid.es
   
   
   
   
   
   
   
                          Expires January 2014                  [Page
     18]
   

Html markup produced by rfcmarkup 1.124, available from https://tools.ietf.org/tools/rfcmarkup/