Network Working Group                             Dimitri Papadimitriou    
    Internet Draft                                         Martin Vigoureux 
    Intended Status: Proposed Standard                       Alcatel-Lucent 
    Expiration Date: April 15, 2010                          Kohei Shiomoto 
    Creation Date: October 16, 2009                                     NTT         
                                                           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-08.txt 
                                         
    Status of this Memo  
            
       This Internet-Draft is submitted to IETF in full conformance with 
       the provisions of BCP 78 and BCP 79. 
        
       Internet-Drafts are working documents of the Internet Engineering 
       Task Force (IETF), its areas, and its working groups.  Note that 
       other groups may also distribute working documents as Internet- 
       Drafts. 
        
       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." 
        
       The list of current Internet-Drafts can be accessed at 
       http://www.ietf.org/ietf/1id-abstracts.txt. 
        
       The list of Internet-Draft Shadow Directories can be accessed at 
       http://www.ietf.org/shadow.html. 
        
        
    Copyright and License Notice 
        
       Copyright (c) 2009 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 in effect on the date of 
       publication of this document (http://trustee.ietf.org/license-info). 
       Please review these documents carefully, as they describe your 
       rights and restrictions with respect to this document. 
         
        
     
     
     
    D. Papadimitriou       Expires April 15, 2010                 [Page 1] 
    

    Internet-Draft                                        October 16, 2009 
        

    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 Content  

       1. Introduction................................................ 2  
       2. Summary of the Requirements and Evaluation.................. 3  
       3. Interface adjustment capability descriptor (IACD)........... 4  
       4. Multi-Region Signaling...................................... 8  
       5. Virtual TE link............................................. 11    
       6. Backward Compatibility...................................... 16  
       7. Security Considerations..................................... 16  
       8. IANA Considerations Sections................................ 17  
       9. References.................................................. 18 
        
    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).  
     
     
    D. Papadimitriou       Expires April 15, 2010                 [Page 2] 
    

    Internet-Draft                                        October 16, 2009 
        

            
       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 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 [MLN-EVAL] and several  
       areas where GMPLS protocol extensions are required are identified.  
           
       This document defines GMPLS routing and signaling extensions so as  
       to cover GMPLS MLN/MRN requirements.    
        
    2. Summary of the Requirements and Evaluation  
        
       As identified in [MLN-EVAL], most 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 [MLN-EVAL]:  
        
       o GMPLS routing extensions for the advertisement of the internal  
         adjustment capability of hybrid nodes. See Section 3.2.2 of [MLN- 
         EVAL]. 
        
       o GMPLS signaling extensions for constrained multi-region signaling  
         (Switching Capability inclusion/exclusion). See Section 3.2.1 of    
         [MLN-EVAL]. An additional eXclude Route object (XRO) Label  
     
     
    D. Papadimitriou       Expires April 15, 2010                 [Page 3] 
    

    Internet-Draft                                        October 16, 2009 
        

         subobject is also defined since absent from [RFC4874].  
        
       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 [MLN-EVAL]. 
        
       o GMPLS routing and signaling extensions for graceful TE-link   
         deletion. See Section 3.1.1.3 of [MLN-EVAL]. 
     
       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]. 
        
       Companion documents address GMPLS OAM (see [GMPLS-OAM]) aspects that 
       have been identified in [MLN-EVAL]. 
        
    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) 
     
     
    D. Papadimitriou       Expires April 15, 2010                 [Page 4] 
    

    Internet-Draft                                        October 16, 2009 
        

       adjustment capability between the LSC and the PSC switching 
       components. Another example occurs when L2SC (Ethernet) switching can 
       be adapted in LAPS X.86 and GFP for instance before reaching the TDM 
       switching matrix. Similar circumstances can occur, if a switching 
       fabric that supports both PSC and L2SC functionalities is assembled 
       with LSC interfaces enabling "lambda" encoding. In the switching 
       fabric, some interfaces can terminate Lambda LSPs and perform frame 
       (or cell) switching whilst other interfaces can terminate Lambda LSPs 
       and perform packet switching.   
            
       Therefore, within multi-region networks, the advertisement of the  
       so-called 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 [MLN-EVAL]. 
         
    3.2 Interface Adjustment Capability Descriptor (IACD)  
            
       The interface adjustment capability descriptor (IACD) provides the  
       information for the forwarding/switching) only 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.  
        
       The IACD sub-TLV format is defined as follows:  
     
     
    D. Papadimitriou       Expires April 15, 2010                 [Page 5] 
    

    Internet-Draft                                        October 16, 2009 
        

            
         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.  
        
          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]    
        
     
     
    D. Papadimitriou       Expires April 15, 2010                 [Page 6] 
    

    Internet-Draft                                        October 16, 2009 
        

          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.  
            
          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   
            
       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 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              |   
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
     
     
    D. Papadimitriou       Expires April 15, 2010                 [Page 7] 
    

    Internet-Draft                                        October 16, 2009 
        

        |                  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)                                   |   
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
            
       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 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.  
           
     
     
    D. Papadimitriou       Expires April 15, 2010                 [Page 8] 
    

    Internet-Draft                                        October 16, 2009 
        

       o If no existing FA-LSP is found, the node sets up a new FA-LSP.   
         That is, it initiates a new LSP setup just for the FA-LSP.    
            
         Note: compatible 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 to the excluded in the XRO but also prevent complex 
       consistency checks but also transpositions between EXRS and XRO at 
       FA-LSP head-ends.  
            
    4.1 XRO Subobject Encoding  
            
       The contents of an EXCLUDE_ROUTE object defined in [RFC4874] are a 
       series of variable-length data items called subobjects.  
        
     
     
    D. Papadimitriou       Expires April 15, 2010                 [Page 9] 
    

    Internet-Draft                                        October 16, 2009 
        

       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 Encoding  
         
       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     |     Length    |   Attribute   | Switching Cap |  
         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  
         
          L  
             0 indicates that the attribute specified MUST be excluded  
             1 indicates that the attribute specified SHOULD be avoided  
            
          Attribute  
              
             0 reserved value  
                    
             1 indicates that the specified SC SHOULD be excluded or   
               avoided with respect to the preceding numbered (Type 1 or   
               Type 2) or unnumbered interface (Type) subobject.  
             
          Switching Cap (8-bits)  
               
             Switching Capability value to be excluded.  
            
       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 Encoding  
        
       XRO Subobject Type 3: Label Subobject  
        
       The encoding of the Label XRO Subobject is identical to the Label ERO 
       Subobject defined in [RFC3473] with the exception of the L bit. For 
       the Label XRO Subobject, the L bit is defined as:   
        
          L 
     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 10] 
    

    Internet-Draft                                        October 16, 2009 
        

             0 indicates that the attribute specified MUST be excluded. 
             1 indicates that the attribute specified SHOULD be avoided. 
        
       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 sub-objects 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 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 

     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 11] 
    

    Internet-Draft                                        October 16, 2009 
        

       "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  
         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  
         |                                                               |  
         //                       Attributes TLVs                       //  
         |                                                               |  
         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  
            
       The 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 Attributes TLVs  
            
       Attributes carried by the CALL_ATTRIBUTES object are encoded within  
       TLVs. One or more TLVs MAY be present in each object.  
            
     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 12] 
    

    Internet-Draft                                        October 16, 2009 
        

       There are no ordering rules for TLVs, and no interpretation SHOULD be  
       placed on the order in which TLVs are received.  
            
       Each TLV is encoded as follows.  
            
         0                   1                   2                   3  
         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1  
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  
        |             Type              |           Length              |  
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  
        |                                                               |  
        //                            Value                            //  
        |                                                               |  
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  
           
          Type  
            
             The identifier of the TLV.  
            
          Length  
             
             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 field 
             does not count any padding. 
                                    
          Value  
                
             The data field for the TLV padded as described above.  
        
    5.1.4 Attributes Flags TLV  
            
       The TLV Type 1 indicates the Attributes Flags TLV. Other TLV types   
       MAY be defined in the future with type values assigned by IANA (see  
       Section 8). The Attributes Flags TLV MAY be present in a  
       CALL_ATTRIBUTES object.    
            
       The Attribute Flags TLV value field is an array of units of 32 flags  
       numbered from the most significant bit as bit zero. The Length field  
       for this TLV is therefore always a multiple of 4 bytes, regardless of  
       the number of bits carried and no padding is required.  
            
       Unassigned bits are considered as reserved and MUST be set to zero on  
       transmission by the originator of the object. Bits not contained in  
     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 13] 
    

    Internet-Draft                                        October 16, 2009 
        

       the TLV MUST be assumed to be set to zero. If the TLV is absent  
       either because it is not contained in the CALL_ATTRIBUTES object or  
       because this object is itself absent, all processing MUST be  
       performed as though the bits were present and set to zero. That is to  
       say, assigned bits that are not present either because the TLV is  
       deliberately foreshortened or because the TLV is not included MUST be  
       treated as though they are present and are set to zero.  
         
    5.1.5 Call Inheritance Flag  
            
       This document introduces a specific flag (most significant bit (msb) 
       position bit 0) of the Attributes Flags TLV, to indicate that the 
       association initiated between the end-points belonging to a call 
       results into a (virtual) TE link advertisement. 
            
       The Call Inheritance Flag MUST be set to 1 in order to indicate that  
       the established association is to be translated into a TE link  
       advertisement. The value of this flag 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 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  
     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 14] 
    

    Internet-Draft                                        October 16, 2009 
        

         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 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).   
     
     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 15] 
    

    Internet-Draft                                        October 16, 2009 
        

       Mechanisms for provisioning (pre-planned or not) LSP with 0 bandwidth   
       is straightforward for PSC the SENDER_TSPEC/FLOWSPEC, the Peak Data  
       Rate field of Int-Serv objects, see [RFC2210], is set to 0. For L2SC  
       LSP, the CIR, EIR, CBS, and EBS MUST be set of 0 in the Type 2 sub- 
       TLV of the Ethernet Bandwidth Profile TLV. In these cases, upon LSP  
       resource commitment, actual traffic parameter values are used to  
       perform corresponding resource reservation.  
            
       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 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.  
     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 16] 
    

    Internet-Draft                                        October 16, 2009 
        

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

       IANA has made the following assignments in the "Class Names, Class 
       Numbers, and Class Types" section of the "RSVP PARAMETERS" registry 
       located at http://www.iana.org/assignments/rsvp-parameters. 
        
       This document introduces a new class named CALL_ATTRIBUTES has been 
       created in the 11bbbbbb range (201) with the following definition: 
     
       Class Number  Class Name                            Reference 
       ------------  -----------------------               --------- 
       201           CALL ATTRIBUTES                [This I-D] 
        
                     Class Type (C-Type): 
        
                     1   Call Attributes                [This.I-D] 
        
       This document introduces 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) 
         
     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 17] 
    

    Internet-Draft                                        October 16, 2009 
        

       Value  Sub-TLV                                               
       -----  -------------------------------------------------    
       24     Interface Adjustment Capability Descriptor (IACD) 
        
    8.3 IS-IS   

       This document defines the following new sub-TLV type of top-level TLV 
       22 that need to be reflected in the ISIS sub-TLV registry for TLV 22: 

       Type   Description                                        Length 
       ----   -------------------------------------------------  ------ 
       24     Interface Adjustment Capability Descriptor (IACD)  Variable 
           
    9. References 
        
    9.1 Normative References 
        
       [GMPLS-RR] Berger, L., Papadimitriou, D., and JP. Vasseur, 
                  "PathErr Message Triggered MPLS and GMPLS LSP Reroute",    
                  draft-ietf-mpls-gmpls-lsp-reroute, Work in progress.   
        
       [HIER-BIS] Shiomoto, K., and Farrel, A., "Procedures for Dynamically  
                  Signaled Hierarchical Label Switched Paths", draft-ietf  
                  ccamp-lsp-hierarchy-bis, Work in progress.   
        
       [RFC2205]  Braden, R., et al., "Resource ReSerVation Protocol 
                  (RSVP) -- Version 1 Functional Specification", 
                  RFC2205, September 1997.  
            
       [RFC2210]  Wroclawski, J., "The Use of RSVP with IETF  
                  Integrated Services", RFC2210, September 1997.  
          
       [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",  
                  RFC3471, January 2003.  
            
       [RFC3473]  Berger, L., "Generalized Multi-Protocol Label  
                  Switching (GMPLS) Signaling Resource ReserVation  
                  Protocol-Traffic Engineering (RSVP-TE) Extensions",  
                  RFC3473, January 2003.  
        
     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 18] 
    

    Internet-Draft                                        October 16, 2009 
        

       [RFC3477]  Kompella, K., and Y. Rekhter, "Signalling Unnumbered Links 
                  in Resource ReSerVation Protocol - Traffic Engineering 
                  (RSVP-TE)", RFC3477, January 2003. 
             
       [RFC3630]  Katz, D., et al., "Traffic Engineering (TE) Extensions to  
                  OSPF Version 2," RFC3630, September 2003.  
            
       [RFC3945]  Mannie, E. and al., "Generalized Multi-Protocol Label  
                  Switching (GMPLS) Architecture", RFC3945, October 2004.  
            
       [RFC4201]  Kompella, K., et al., "Link Bundling in MPLS Traffic      
                  Engineering", RFC4201, October 2005.  
            
       [RFC4202]  Kompella, K., Ed., and Rekhter, Y. Ed., "Routing  
                  Extensions in Support of Generalized MPLS", RFC4202,  
                  October 2005.  
            
       [RFC4203]  Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions  
                  in Support of Generalized Multi-Protocol Label Switching  
                  (GMPLS)", RFC4203, October 2005.  
           
       [RFC4206]  Kompella, K., and Rekhter, Y., "LSP Hierarchy with 
                  Generalized MPLS TE", RFC4206, October 2005. 
        
       [RFC4306]  Kaufman, C., Ed., "Internet Key Exchange (IKEv2)  
                  Protocol", RFC4306, 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. RFC4606, August 2006.  
                  
       [RFC5305]  Smit, H. and T. Li, "Intermediate System to  
                  Intermediate System (IS-IS) Extensions for Traffic  
                  Engineering (TE)", RFC5305, 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)", RFC5307, 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,"  
     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 19] 
    

    Internet-Draft                                        October 16, 2009 
        

                  RFC4874, April 2007.  
            
       [RFC4974]  Papadimitriou, D., and Farrel, A., "Generalized MPLS  
                  (GMPLS) RSVP-TE Signaling Extensions in support of Calls,"    
                  RFC4974, August 2007. 
        
    9.2 Informative References 
     
       [GMPLS-OAM] Nadeau, T., Otani, T. Brungard, D., and A. Farrel, "OAM 
                   Requirements for Generalized Multi-Protocol Label 
                   Switching (GMPLS) Networks", Work in Progress, October 
                   2007. 
        
       [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. 
        
       [MLN-EVAL]  Leroux, J.-L., et al., "Evaluation of existing GMPLS   
                   Protocols against Multi Region and Multi Layer Networks  
                   (MRN/MLN)", RFC 5339, September 2008. 
            
       [RFC5212]   Shiomoto, K., et al., "Requirements for GMPLS-based  
                   multi-region and multi-layer networks (MRN/MLN)",    
                   RFC5212, July 2008.  
        
       [MPLS-SEC]  Fang, L. Ed., "Security Framework for MPLS and GMPLS 
                   Networks", draft-ietf-mpls-mpls-and-gmpls-security-
                   framework, Work in progress. 
            
       [MLRT]      Imajuku, W., et al., "Multilayer routing using multilayer  
                   switch capable LSRs", draft-imajuku-ml-routing-02.txt, 
                   Work in Progress. 
     
    Acknowledgments 
     
       The authors would like to thank Mr. Wataru Imajuku for the 
       discussions on adjustment between regions [MLRT]. 
                 
    Author's Addresses 
        
       Dimitri Papadimitriou 
       Alcatel-Lucent Bell 
       Copernicuslaan 50 
       B-2018 Antwerpen, Belgium 
       Phone: +32 3 2408491 
       E-mail: dimitri.papadimitriou@alcatel-lucent.be 
        
     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 20] 
    

    Internet-Draft                                        October 16, 2009 
        

       Martin Vigoureux  
       Alcatel-Lucent    
       Route de Villejust  
       91620 Nozay, France  
       Tel : +33 1 30 77 26 69  
       Email: martin.vigoureux@alcatel-lucent.fr  
            
       Kohei Shiomoto   
       NTT   
       3-9-11 Midori-cho  
       Musashino-shi, Tokyo 180-8585, Japan  
       Phone: +81 422 59 4402  
       Email: shiomoto.kohei@lab.ntt.co.jp  
            
       Deborah Brungard   
       ATT  
       Rm. D1-3C22 - 200 S. Laurel Ave.  
       Middletown, NJ 07748, USA  
       Phone: +1 732 420 1573  
       Email: dbrungard@att.com   
            
       Jean-Louis Le Roux   
       France Telecom  
       Avenue Pierre Marzin  
       22300 Lannion, France  
       Phone: +33 (0)2 96 05 30 20  
       Email: jean-louis.leroux@rd.francetelecom.com 
        
    Contributors 
         
       Eiji Oki   
       NTT Network Service Systems Laboratories  
       3-9-11 Midori-cho  
       Musashino-shi, Tokyo 180-8585, Japan  
       Phone : +81 422 59 3441  
       Email: oki.eiji@lab.ntt.co.jp  
     
       Ichiro Inoue  
       NTT Network Service Systems Laboratories  
       3-9-11 Midori-cho  
       Musashino-shi, Tokyo 180-8585, Japan  
       Phone : +81 422 59 6076  
       Email: ichiro.inoue@lab.ntt.co.jp  
         
       Emmanuel Dotaro    
       Alcatel-Lucent France  
       Route de Villejust  
     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 21] 
    

    Internet-Draft                                        October 16, 2009 
        

       91620 Nozay, France  
       Phone : +33 1 6963 4723  
       Email: emmanuel.dotaro@alcatel-lucent.fr  
         
       Gert Grammel   
       Alcatel-Lucent SEL  
       Lorenzstrasse, 10  
       70435 Stuttgart, Germany  
       Email: gert.grammel@alcatel-lucent.de 
        
        



































     
     
    D. Papadimitriou       Expires April 15, 2010                [Page 22]