One document matched: draft-papadimitriou-ccamp-gmpls-l2sc-lsp-03.txt

Differences from draft-papadimitriou-ccamp-gmpls-l2sc-lsp-02.txt


CCAMP Working Group                          D. Papadimitriou (Alcatel) 
Internet Draft                                        D. Brungard (ATT) 
Expiration Date: April 2005                      M. Vigoureux (Alcatel) 
                                                  A. Ayyangar (Juniper) 
                                                                        
                                                           October 2004 
 
    
               Generalized MPLS (GMPLS) RSVP-TE Signaling  
          in support of Layer-2 Label Switched Paths (L2 LSP) 
    
            draft-papadimitriou-ccamp-gmpls-l2sc-lsp-03.txt 
    
    
Status of this Memo 
        
   This document is an Internet-Draft and is subject to all provisions 
   of section 3 of RFC 3667. By submitting this Internet-Draft, each 
   author represents that any applicable patent or other IPR claims of 
   which he or she is aware have been or will be disclosed, and any of  
   which he or she become aware will be disclosed, in accordance with  
   RFC 3668.  
        
   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.  
        
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Copyright Notice  
        
   Copyright (C) The Internet Society (2004). All Rights Reserved. 
 
Abstract 
    
   Most efforts on Generalized MPLS (GMPLS) have been focused on 
   environments covering Circuit oriented LSPs (Sonet/SDH, OTH, etc.). 
   There is minimal documentation on GMPLS support of Layer-2 Label 
   Switched Paths (L2 LSPs), e.g. native Ethernet LSPs, Asynchronous 
   Transfer Mode (ATM) LSPs and Frame Relay (FR) LSPs. 
    
   This document details GMPLS capabilities for supporting L2 LSPs in 
   several network environments including overlays. As such, it 
   provides a reference detailing the applicability of GMPLS for Layer-
   2 switching environments in support of various deployment scenarios, 
  
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   including the integrated (e.g. multi LSP-region networks), the 
   augmented/peer and the overlay model (e.g. Generalized VPN (GVPN) 
   and user-network interfaces (GMPLS UNI)). 
    
1. 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. 
    
   In addition the reader is assumed to be familiar with the terms and 
   concepts developed in [RFC3945], [RFC3471], [RFC3473], [RFC3477], 
   and [GMPLS-UNI], [GMPLS-ENNI] as well as [HIER] and [BUNDLE]. 
    
   The following abbreviations are used in this document:  
    
   CN:     Core node 
   DLCI:   Data Link Connection Identifier 
   EN:     Edge node 
   ICN:    Ingress core node 
   ECN:    Egress core node 
   FA:     Forwarding Adjacency 
   FR:     Frame Relay  
   FSC:    Fiber-Switch Capable 
   HOVC:   Higher order virtual container   
   ISC:    Interface Switching Capability 
   L2-LSP: Layer-2 Label Switched Path 
   L2SC:   Layer-2 Switch Capable  
   LOVC:   Lower order virtual container  
   LSC:    Lambda Switch Capable   
   PSC:    Packet Switch Capable   
   OTH:    Optical transport hierarchy 
   SDH:    Synchronous digital hierarchy.  
   SONET:  Synchronous Optical Network.  
   TDM:    Time-Division Multiplex  
   VCI:    Virtual Channel Identifier 
   VPI:    Virtual Path Identifier       
    
2. Introduction 
    
   Generalized Multi-Protocol Label Switching (GMPLS) extends MPLS to 
   support four new classes of interfaces Layer-2 Switch Capable (L2SC), 
   Time-Division Multiplex (TDM) capable, Lambda Switch Capable (LSC) 
   and Fiber-Switch Capable (FSC) in addition to Packet Switch Capable 
   (PSC) already supported by MPLS. All these interface classes have 
   been considered in [GMPLS-ARCH], [GMPLS-RTG] and [RFC3471]. 
    
   However, most of the efforts have been concentrated in facilitating 
   the realization of seamless control integration of IP/MPLS networks 
   with SONET/SDH (see [T1.105]/[G.707]) or OTH (see [G.709]) transport 
   networks. The integration of packet and circuit switching 
   technologies under a unified GMPLS control plane provides an 
   homogeneous control management approach for both provisioning 
  
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   resources and recovery techniques (including protection and re-
   routing). 
    
   While being introduced in [GMPLS-ARCH], [GMPLS-RTG] and [RFC3471], 
   the GMPLS capability to control L2SC TE links and L2 LSPs has 
   received very little attention. [RFC3471] defines the Ethernet 
   encoding types (i.e. the encoding of the LSP being requested) and 
   Layer-2 as switching capability (i.e. the type of switching to be 
   performed on a particular link). In this document, a L2 LSP is 
   defined as a LSP being established between intermediate L2SC 
   interfaces. These interfaces are defined as being capable of 
   recognizing frame/cell boundaries and can switch data based on the 
   content of the frame/cell header (example: interfaces on Ethernet 
   switches that switch data based on the content of the MAC header). 
    
   The motivation for considering GMPLS control of L2 LSPs can be 
   summarized as follows: 
   - it automates the provisioning of transparent LAN services. Today,  
     the delivery of such services can not be automated due to the  
     control plane/topology driven nature of GMPLS that precludes the  
     automated triggering of the server layer LSP from an incoming data  
     flow.  
   - it facilitates the transport of Ethernet flows without introducing  
     additional intermediate packet layer LSPs that require themselves  
     pre-provisioning actions as network trunks that can not be  
     triggered from external traffic demands.   
   - it delivers control plane driven recovery capabilities for  
     a range of technologies (e.g. Ethernet) making classically usage  
     of mechanisms adapted only for environments where these data plane  
     technologies had been initially introduced. For instance, Ethernet  
     Spanning Tree Protocol is less suitable in meshed environments  
     where control plane driven fast recovery is required and available  
   - it simplifies the carrier network operations by avoiding dedicated  
     control protocols for managing Ethernet environments that are not  
     adapted for large scale environments and for which an IP-based  
     protocol counter-part exists (e.g. OSPF). 
   - the use of an IP based addressing scheme elevates the scaling  
     issues generated by the non-hierarchical MAC addressing scheme.  
     This capability allows constructing large scale networks taking  
     advantage of the IP addressing properties (at the control plane  
     level). 
   - it delivers an homogeneous set of signaling mechanisms for  
     controlling L2 technologies for which integration in common  
     infrastructure is made difficult due to their particularities  
     (e.g. ATM and FR).  
 
3. Context 
    
   The reference network considered (but not restricted to) in this 
   document is provided in [GMPLS-UNI], [GMPLS-ENNI] and [RFC3473].  
    
3.1 GMPLS UNI 
    
  
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   This network is constituted by a core network including core-nodes 
   (CN) surrounded by edge nodes (EN) that form the overlay networks. In 
   addition, the present document assumes the Traffic Engineering (TE) 
   links inter-connecting the edge and the core nodes are of type 
   [X,L2SC], where X is any ISC whose switched payload can be carried 
   over L2SC TE links.  
    
   Within the network, the links interconnecting the core nodes can be 
   either [L2SC,L2SC] or any other technology that can carry Layer-2 
   payload, in particular [TDM,TDM] and [LSC,LSC]. Note also that in the 
   first case, the EN-CN interface defines an LSP region boundary (see 
   [HIER]). In the second case, this boundary may be found within the 
   network. 
    
   As defined in [HIER], a (data plane) switching layer is mapped to a 
   (control plane) LSP region. Following this approach, TE links have 
   been extended to non adjacent nodes by the introduction of 
   Forwarding Adjacency (FA). Using this concept, a node may (under the 
   control of its local policy configuration) advertise an LSP as a TE 
   link into the same IGP routing instance as the one that induces this 
   LSP. Such a link is referred to as a Forwarding Adjacency (FA) and 
   the corresponding LSP to a Forwarding Adjacency LSP (FA-LSP). Since 
   the advertised entity appears as a TE link, both end-point nodes of 
   the FA-LSP must belong to the same OSPF area/IS-IS level. 
   Afterwards, OSPF/IS-IS floods the link-state information about FAs 
   just as it floods the information about any other TE link. This 
   allows other nodes to use FAs as any other TE links for path 
   computation purposes. 
 
3.2 GMPLS E-NNI 
    
   When two core networks (1 and 2) are interconnected by two core 
   nodes (CN1 and CN2), they define an external network-network 
   interface, as illustrated by the following (simplified) topology: 
         
            B---C           F---G 
           /     \         /     \ 
        --A   1   CN1---CN2   2   H-- 
           \     /         \     / 
            E---D           J---I 
    
   In this topology, [A,B], [A,E] and their network 2 counter part are 
   [L2SC,Y] TE links. Then, the first possibility is that [C,CN1], 
   [D,CN1] TE links and their network 2 counter part are [Y,L2SC] TE 
   Links, and [CN1,CN2] is a [L2SC,L2SC] TE link. Therefore, the L2 LSP 
   that can be setup between node A (ingress) and node H (egress) may 
   be constituted by two FA LSPs (the first between A and CN1 and the 
   second between CN2 and H) interconnected by the [L2SC,L2SC] TE link 
   defined at the E-NNI. 
    
   The other possibility is that the [CN1,CN2] TE link is not a 
   [L2SC,L2SC] TE link. For example, this could be a multi-AS transport 
   scenario where [CN1,CN2] TE link cannot terminate the L2 LSP. In 
  
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   this case, CN1 and CN2 would only be transporting the L2 LSP from A 
   to H on top of some other LSP. So, the TE link between [CN1,CN2] 
   would then have to be [Y,Y] in which case there would be a single 
   FA-LSP from A to H. 
    
   Applicability of GMPLS RSVP-TE signaling [RFC-3473] at the E-NNI is 
   detailed in [GMPLS-ENNI]. 
    
3.3 GMPLS Signaling Channel 
    
   For nodes inter-connected by point-to-point native L2 interfaces, the 
   signaling channel may be out-of-band or in-band. In the latter case, 
   several implementation choices are possible for the GMPLS signaling 
   channel: 1) specific Ethertype that allows discrimination between 
   data and control traffic (that may be directed towards a dedicated 
   destination MAC address), 2) dedicated VLAN ID, VPI/VCI (see 
   [RFC3035], Section 7) or DLCI (see [RFC3034], Section 6) for the 
   control traffic, and 3) use of a dedicated destination MAC address 
   for reaching the peering GMPLS controller. Nevertheless, the 
   signaling transport implementation MUST be strictly independent of 
   the signaling transport mechanism used between peering GMPLS nodes. 
 
4. Addressing 
    
   Addressing follows the rules defined in [GMPLS-UNI] and [GMPLS-
   ENNI]. The SESSION and SENDER_TEMPLATE/FILTER_SPEC objects are end-
   to-end significant i.e. a single end-to-end RSVP session is defined 
   (in compliance with the RSVP paradigm).  
 
5. Signaling 
    
   L2 LSP setup, notification, graceful and non-graceful deletion 
   procedures follow [RFC3471], [RFC3473] including Graceful Restart 
   upon control channel and node failure, [GMPLS-UNI] and [GMPLS-ENNI]. 
   Signaling mechanisms applies to both uni- and bi-directional L2 LSP. 
    
   Translation of the L2 LSP request at the edge CN can make use of one 
   of the following method: 1) direct end-to-end LSP [RFC3473], 2) LSP 
   splicing i.e. the tail-end of the incoming LSP is attached to the 
   head-end of the outgoing LSP (see [RFC3471]) and stitching, 3) LSP 
   nesting into a FA-LSP [HIER]. Note that techniques for automated LSP 
   stitching are described in [MPLS-IRN].  
    
   Also, in the overlay context, L2 LSPs nesting into a FA-LSP can be 
   used when the ingress/egress edge CN provides (flow) multiplexing 
   capabilities. 
    
5.1 L2 Generalized Label Request 
    
   The Generalized Label Request is defined in [RFC3471], Section 3.1. 
   The different LSP Encoding Type and Switching Type (of the 
   GENERALIZED_LABEL REQUEST object) that can be used for requesting L2 
   LSP label is detailed in Table 1.  
  
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   Value        LSP Encoding type       Value   Switching Type   
   -----        -----------------       -----   --------         
   2            Ethernet                51      L2SC     
   14 (new)     ATM                     51      L2SC             
   15 (new)     Frame-Relay             51      L2SC              
    
         Table 1: LSP Encoding Type and Switching Type code-points  
                       for Ethernet, ATM and FR LSPs 
                                      
   For the Generalized PID (G-PID) that identifies the payload carried 
   by an LSP, standard Ethertype values are used for Ethernet LSPs.  
 
5.2 L2 SENDER_TSPEC and FLOWSPEC 
    
   New L2 SENDER_TSPEC and FLOWSPEC objects are introduced to describe 
   bandwidth and delay/jitter characteristics for the L2 LSP as well as 
   any such L2 traffic specific characteristics.  
    
   As per [RFC3471], GMPLS allows the inclusion of technology specific 
   parameters in signaling. The intent is for all technology specific 
   parameters to be carried, when using RSVP-TE, in the SENDER_TSPEC 
   and other related objects. So new L2 SENDER_TSPEC and FLOWSPEC 
   objects are defined as follows. These traffic parameters MUST be 
   used when L2SC is specified in the LSP Switching Type field of a 
   Generalized Label Request (see [RFC3471]) and the LSP encoding type 
   is Ethernet, ATM or Frame-Relay.  
    
5.2.1 L2 SENDER_TSPEC object 
    
   The L2 SENDER_TSPEC object (Class-Num = 12, Class-Type = 6) has the 
   following format: 
 
       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 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |            Length             | Class-Num (12)|   C-Type (6)  | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |     Switching Granularity     |              MTU              | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                                                               | 
      ~                              TLVs                             ~ 
      |                                                               | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
      Switching Granularity (SG): 16 bits 
    
        This field indicates the type of L2 link that comprises the  
        requested LSP. 
     
        The permitted L2 Link Type values: 
    
        Value   Switching Granularity 
  
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        -----   ------------------------ 
        1       Ethernet Port 
        2       Ethernet VLAN 
        3       ATM Port 
        4       ATM VP Bundle 
        5       ATM VP 
        6       ATM VC 
        7       Frame Relay Port 
        8       Frame Relay DLCI 
    
        Value 0 is reserved. Values 128 through 255 are reserved for  
        vendor specific usage. 
    
      MTU: 16 bits 
         
        This is a two-octet value indicating the MTU in octets. 
         
        Note: the notion of MTU does not apply to ATM LSPs (fixed cell 
        size of 53 bytes) and MUST thus be set to 53. 
         
      TLV: 
    
        The L2 SENDER_TSPEC object MUST include at least one (i.e. the 
        Type 1 TLV) and MAY include more than one optional TLV (for 
        which the Type is > 1). Type 1 TLV MAY appear at most once 
        per SENDER_TSPEC object.  
    
        Each TLV has the following format: 
 
       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                             ~ 
      |                                                               | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
      Length: 16 bits 
    
         Indicates the total length of the TLV, i.e., 4 + the length of 
         the value field in octets. A value field whose length is not  
         a multiple of four MUST be zero-padded so that the TLV is  
         four-octet aligned. 
    
      Type: 16 bits 
    
         Defined values are: 
    
         Type    Length         Format          Description 
         -------------------------------------------------- 
         1       20             See below       L2_QoS  
  
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         Types 128 through 255 are reserved for vendor specific TLVs. 
         Additional L2 technology specific TLVs MAY be defined in 
         future revision of this document. 
    
         Type 1 TLV (L2 QoS) Indicates the QoS type of the traffic. 
         This TLV has the following format: 
    
       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 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      | Service Class |                   Reserved                    | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |           Bandwidth (32-bit IEEE floating point number)       | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                      Jitter (microseconds)                    | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                      Delay (microseconds)                     | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
      Service Class: 8 bits 
    
         Identifies the service class i.e. the tuples <bandwidth,  
         jitter, delay> that can be constructed using this TLV. Default  
         value is 0x0001. Value range 0x0000 to 0x0008 is reserved as 
         part of this document. 
    
      Reserved: 24 bits 
    
         These bits SHOULD be set to zero when sent and MUST be ignored  
         when received. 
    
      Bandwidth: 32 bits  
    
         The requested bandwidth for the L2 LSP. The unit is bytes per  
         second. For instance, a 1Gbps Ethernet LSP will have a value  
         of 0x4CEE6B28.  
    
      Jitter: 32 bits 
    
         Indicates the maximum acceptable jitter (in microseconds) for  
         this LSP. If unspecified, this value is set to 0x00000000. 
    
      Delay: 32 bits 
    
         Indicates the maximum acceptable delay (in microseconds) for  
         this LSP. If unspecified, this value is set to 0x00000000. 
 
5.2.2 L2 FLOWSPEC object 
    
   The L2 FLOWSPEC object (Class-Num = 12, Class-Type = 6) has the same 
   format as the L2 SENDER_TSPEC object. 
    
  
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5.2.3 Processing 
    
   The L2 SENDER_TSPEC object carries the traffic specification 
   generated by RSVP session sender. The L2 SENDER_TSPEC object SHOULD 
   be forwarded and delivered unchanged to both intermediate and egress 
   nodes. The L2 FLOWSPEC object carries reservation request 
   information generated by receivers. As any FLOWSPEC object, the 
   information content of the L2 FLOWSPEC object flows upstream towards 
   ingress node. 
 
   For a particular sender in a RSVP session the contents of the 
   FLOWSPEC object received in a Resv message SHOULD be identical to 
   the contents of the SENDER_TSPEC object sent in the corresponding 
   Path message. If the objects do not match, a ResvErr message with a 
   "Traffic Control Error/Bad Flowspec value" error SHOULD be 
   generated. 
    
   Intermediate and egress nodes MUST verify that the node itself and 
   the interfaces on which the LSP will be established can support the 
   requested Switching Granularity, MTU and values included in sub-
   object TLVs. If the requested value(s) can not be supported, the 
   receiver node MUST generate a PathErr message with a "Traffic 
   Control Error/Service unsupported" indication (see [RFC2205]).  
    
   In addition, if the MTU field is received with a value smaller than 
   the minimum transfer unit size of the L2 specific technology (e.g. 
   46 bytes for Ethernet, 38 bytes for IEEE 802.3), the node MUST 
   generate a PathErr message with a "Traffic Control Error/ Bad Tspec 
   value" indication (see [RFC2205]). 
    
   There is no specific Adspec associated with the L2 SENDER_TSPEC. 
   Either the Adspec is omitted or an Int-serv Adspec with the Default 
   General Characterization Parameters and Guaranteed Service fragment 
   is used, see [RFC2210]. 
    
5.3 L2 Label  
    
   L2 LABEL object follows the generic rules of the GENERALIZED_LABEL 
   object (Class-Num = 16) defined in [RFC3471] for the C-Type 2. This 
   is a 32-bit label value that allows the sending and receiving node 
   performing the link local operations for the requested L2 LSP.  
    
   The interpretation of the received label depends on the type of the 
   link over which the label is used. The received label MUST be 
   interpreted according the requestor traffic parameters, i.e. a label 
   by itself does not allow knowing the detailed properties of the L2 
   LSP being requested (i.e. L2 labels are context sensitive). 
     
   Table 2 summarizes the L2 labels representation (that can be 
   supported over [X,L2SC], [L2SC,L2SC] and [L2SC,X] TE links) and 
   assigned upon reception of the LSP Encoding and Switching Types: 
    
   LSP Encoding type    Switching Type  Label   
  
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   -----------------    --------------  ----------------------------- 
   Ethernet             L2SC            Port, VLAN ID 
   ATM                  L2SC            Port, VPI, VCI, VP Bundle ID 
   Frame-Relay          L2SC            Port, DLCI  
    
                            Table 2. L2 Labels 
    
   Ethernet Port, ATM Port and Frame Relay Port labels are encoded 
   right justified aligned in 32 bits (4 octets). Ethernet VLAN ID 
   labels are encoded with the VLAN ID value (12 bits) right justified 
   in bits 20-31 (and preceding bits must be set to 0). ATM VPI/VCI 
   labels are encoded per [RFC3036] Section 3.4.2.2. Frame-Relay DLCI 
   label values are encoded per [RFC3036] Section 3.4.2.3. Note that 
   the VLAN label space should be applicable on per port basis, 
   otherwise the number of LSP per node is limited to 4096. This 
   applies also most likely to ATM and FR nodes. 
    
   Bi-directional L2 LSPs are indicated by the presence of an upstream 
   label in the Path message. Upstream label assignment follows the 
   format of the UPSTREAM LABEL object and the procedures defined in 
   [RFC3473]. 
    
5.4 Interface Identification 
    
   Interface identification follows the rules defined in [RFC3473], 
   Section 8.1 and [RFC3477]. 
 
6. Explicit Routing 
 
6.1 EXPLICIT_ROUTE Object (ERO) Processing 
    
   EXPLICIT ROUTE objects can make use of the subobjects defined in 
   [RFC3209] for numbered TE links, [RFC3477] for unnumbered TE links 
   and finally [RFC3473] for labels. EXPLICIT ROUTE objects processing 
   MUST follow the procedures defined in [RFC3209], [RFC3473], 
   [RFC3477], and [GMPLS-UNI] and [GMPLS-ENNI] when applicable. 
    
6.2 RECORD_ROUTE Object (RRO) Processing 
    
   RECORD ROUTE objects can make use of the subobjects defined in  
   [RFC3209] for numbered TE links and labels, [RFC3477] for unnumbered 
   TE links. RECORD ROUTE objects processing MUST follow the procedures 
   defined in [RFC3209], [RFC3473], [RFC3477], and [GMPLS-UNI], [GMPLS-
   ENNI] when applicable. 
    
6.3 Explicit Label Control 
    
   Explicit label control refers to the label identification of the 
   egress TE link. An ingress node may include an ERO for which the 
   last hop includes the node_ID of the egress node and any other sub-
   objects necessary to uniquely identify the TE link, component link 
   and labels for the requested Ethernet LSP. See [EGRESS-CONTROL] for 
   procedural details. 
  
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   Note: in the overlay context, when the L-bit is set, this last-hop 
   may be the only hop included in the ERO (see [GMPLS-UNI]). 
 
7. Security considerations 
    
   The introduction of layer-2 label switched path, particularly in 
   Ethernet networks may raise some security issues that need to be 
   solved.  
    
   The solution MUST protect against the traditional following security 
   threats: 
    
   - Possibility for the network to control the traffic injected by the  
     client in the data plane (BPDU, Multicast, Broadcasts, etc.) or  
     the control plane (using RSVP-TE signaling for setting-up or  
     tearing down the L2 LSPs)      
   - All usual threats brought by IP functionalities (control and data  
     plane) 
   - Entry points induced by the possible coexistence of the two  
     technologies (L2LSPs and usual Broadcast Ethernet mode) 
    
   Current RSVP security mechanisms [RFC2207], [RFC3097] should also be 
   analyzed/evaluated in the context of L2 LSPs. 
    
7.1 Attacks on the Data Plane 
    
   This category encompasses attacks on the Data Plane. Attacks on the 
   data plane can be of the following form:  
        - modification of data traffic 
        - insertion of non-authentic data traffic 
        - Denial of Service (DoS) attacks 
        - traffic snooping 
    
   Introduction of L2 LSP signaling MUST prevent these attacks by 
   offering adequate filters (like ACLs or some new means). 
    
   L2 LSP SHOULD reduce data plane threats, as the number of network 
   entry points to control is reduced. A L2 LSP is by nature a hermetic 
   tunnel, with a single entry point (head-end LSR). Policing and 
   filtering is required only on the head-end LSR. 
    
   Moreover, some mechanism MUST be provided at the network edges (on 
   the head-end LSRs), in order to rate limit the amount of traffic 
   that can transit into a given L2 LSP.  
    
7.2 Attacks on the Control Plane 
    
   There are two threats concerning the control plane. The first one 
   corresponds to the potential initiation of the signaling by the 
   client side. As LSP tunnels MAY be signaled from the client site 
   using RSVP-TE, control of such activity MUST be provided so that it 


  
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   cannot be used to fail the entire network. Note that this applies 
   generally to any client signaling approach.  
    
   There MUST be a way to limit, by configuration, the number of TE-
   LSPs that can be signaled by a particular client, also there must be 
   a way to rate limit RSVP client control plane traffic (mainly 
   refresh interval).   
    
   Also the operator MUST be able to rate limit, by configuration, the 
   total amount of memory and CPU allocated to the RSVP process on a 
   given LSR, and react appropriately when such bound is reached (see 
   [SHORT]) 
    
   Another threat with regards to the Control Plane comes from the 
   introduction of IP functions in L2 equipments (such as the handling 
   of multicast and so on). Indeed L2 networks will inherit all 
   security issue of IP networks. 
    
7.3 Security problems induced by the migration 
    
   If both L2 LSPs and classical Ethernet are used on the same network, 
   then different ranges of VLANs must be considered so that different 
   traffics, with different VLAN semantics do not get mixed for 
   example. 
    
8. IANA Considerations 
    
   Two values have to be defined by IANA for this document. 
    
   Two RSVP C-Types in registry:  
    
   http://www.iana.org/assignments/rsvp-parameters 
 
   - L2 SENDER_TSPEC object: Class = 12, C-Type = 6 (Suggested value)  
    
   - L2 FLOWSPEC object: Class = 9, C-Type = 6 (Suggested value) 
    
   IANA is also requested to track the code-point spaces extended 
   and/or updated by this document. That is: 
   - LSP Encoding Type 
   - Generalized PID (G-PID) 
 
9. Acknowledgments 
    
   The authors would like to acknowledge Emmanuel Dotaro for the 
   fruitful discussions and Mastuura Nobuaki for his useful comments to 
   this document. 
    
   The author would like to thank Jean-Louis Leroux, Simon Delord and 
   Romain Insler for their contribution on the security section.  
    
10. References 
    
  
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10.1 Normative References 
    
   [BUNDLE]    K.Kompella et al., "Link Bundling in MPLS Traffic 
               Engineering", Internet Draft, Work in Progress, draft-
               ietf-mpls-bundle-04.txt, July 2002. 
    
   [GMPLS-ENNI]D.Papadimitriou et al., "Generalized MPLS (GMPLS) RSVP-
               TE Signalling in support of Automatically Switched 
               Optical Network (ASON)." Internet Draft, Work in 
               progress, draft-ietf-ccamp-gmpls-rsvp-te-ason-02.txt, 
               July 2004. 
         
   [GMPLS-UNI] G.Swallow et al., "GMPLS UNI: RSVP Support for the 
               Overlay Model", Internet Draft, Work in Progress, draft-
               ietf-ccamp-gmpls-overlay-04.txt, April 2004. 
                
   [GMPLS-RTG] K.Kompella and Y.Rekhter (Editors) et al., "Routing 
               Extensions in Support of Generalized MPLS", Internet 
               Draft, Work in Progress, draft-ietf-ccamp-gmpls-routing-
               09.txt, October 2003. 
 
   [HIER]      K.Kompella and Y.Rekhter, "LSP Hierarchy with 
               Generalized MPLS TE", Internet Draft, Work in Progress, 
               draft-ietf-mpls-lsp-hierarchy-08.txt, September 2002.  
 
   [RFC2205]   R.Braden (Editor) et al., "Resource ReserVation 
               Protocol -- Version 1 Functional Specification", RFC 
               2205, September 1997. 
    
   [RFC2210]   J.Wroclawski, "The Use of RSVP with IETF Integrated 
               Services", RFC 2210, September 1997. 
                       
   [RFC2961]   L.Berger et al., "RSVP Refresh Overhead Reduction 
               Extensions", RFC 2961, April 2001. 
    
   [RFC3034]   A.Conta et al., "Use of Label Switching on Frame Relay 
               Networks Specification", RFC 3034, January 2001. 
    
   [RFC3035]   B.Davie et al., "MPLS using LDP and ATM VC Switching", 
               RFC 3035, January 2001. 
    
   [RFC3036]   L.Andersson et al., "LDP Specification", RFC 3036, 
               January 2001. 
    
   [RFC3209]   D.Awduche et al., "RSVP-TE: Extensions to RSVP for 
               LSP Tunnels", RFC 3209, December 2001. 
 
   [RFC3471]   L.Berger (Editor) et al., "Generalized Multi-Protocol 
               Label Switching (GMPLS) - Signaling Functional 
               Description", RFC 3471, January 2003. 
    



  
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   [RFC3473]   L.Berger (Editor) et al., "Generalized Multi-Protocol 
               Label Switching (GMPLS) Signaling Resource ReserVation 
               Protocol-Traffic Engineering (RSVP-TE) Extensions", 
               RFC 3473, January 2003. 
 
   [RFC3477]   K.Kompella and Y.Rekhter, "Signalling Unnumbered 
               Links in Resource ReserVation Protocol-Traffic 
               Engineering (RSVP-TE)", RFC 3477, January 2003. 
    
   [RFC3667]   S.Bradner, "IETF Rights in Contributions", BCP 78, 
               RFC 3667, February 2004. 
    
   [RFC3668]   S.Bradner, Ed., "Intellectual Property Rights in IETF 
               Technology", BCP 79, RFC 3668, February 2004. 
    
   [RFC3945]   E.Mannie (Editor) et al., "Generalized Multi-Protocol 
               Label Switching (GMPLS) Architecture", RFC 3945, 
               October 2004. 
    
   [SHORT]     Le Roux, J.L., Mazeas, J.Y, "Procedure to handle RSVP-
               TE control resources shortages", Work in progress, 
               draft-leroux-mpls-rsvp-rsc-shortage-00.txt, October 
               2004. 
    
10.2 Informative References 
    
   [MPLS-IRN]  A.Ayyangar et al., "Inter-region MPLS Traffic 
               Engineering", Internet Draft, Work in progress, draft-
               ayyangar-inter-region-te-01.txt, October 2003. 
                   
11. Author's addresses 
    
   Dimitri Papadimitriou (Alcatel) 
   Francis Wellensplein 1,  
   B-2018 Antwerpen, Belgium 
   Phone : +32 3 240 8491 
   EMail: dimitri.papadimitriou@alcatel.be 
    
   Deborah Brungard (AT&T) 
   Rm. D1-3C22 - 200 S. Laurel Ave. 
   Middletown, NJ 07748, USA 
   Phone: +1 732 420 1573 
   EMail: dbrungard@att.com 
    
   Martin Vigoureux (Alcatel) 
   Route de Nozay,  
   91461 Marcoussis cedex, France 
   Phone: +33 1 6963 1852 
   EMail: martin.vigoureux@alcatel.fr 
    
   Arthi Ayyangar (Juniper) 
   1194 N.Mathilda Ave 
   Sunnyvale, CA 94089, USA 
  
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   EMail: arthi@juniper.net 
 




















































  
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Acknowledgment 
 
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PAFTECH AB 2003-20262026-04-21 21:48:28