One document matched: draft-jounay-pwe3-dynamic-pw-update-00.txt




Network Working Group                                         F. Jounay 
Internet Draft                                                 P. Niger 
Category: Standards Track                                France Telecom 
Expires: May 2008                                                       
                                                             Y(J) Stein 
                                                               RAD Data 
                                                         Communications 
                                                                        
                                                                H. Shah 
                                                             Ciena Corp 
                                                                        
                                                      November 12, 2007 
 
    
                    Dynamic Update of PW Parameters 
                    
                draft-jounay-pwe3-dynamic-pw-update-00.txt 
    
Status of this Memo 
 
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Abstract 
    
   This draft aims at providing a generic solution for updating PW 
   characteristics (interface parameters, label) on-the-fly without 
   service interruption. The document specifies a new generic PWE 
   control protocol mechanism called the PW Update. A PW Update LDP 
   sub-TLV is defined for that purpose. It defines the signaling 
   extension and describes the procedures to dynamically update the PW 
   parameters. A use case is provided for CESoPSN PWs.  
    
 
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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. 
 
    
    
    
 
Table of Contents 
    
    
   1. Terminology.....................................................3 
   2. Introduction....................................................3 
   3. Motivation......................................................3 
   4. Overview of the solution........................................3 
   5. PW Update LDP TYPE TLV..........................................5 
   6. Generic PW Capacity Update......................................6 
     6.1. Update Procedure............................................6 
     6.2. PW Update Mechanism Reference Model.........................7 
     6.3. Control Plane...............................................7 
     6.4. Data Plane..................................................8 
   7. Use Case: CESoPSN...............................................8 
     7.1. Interface Parameters for CESoPSN PWs................... ....9 
       7.1.1. CEP/TDM Payload Bytes (0x04)............................9 
       7.1.2. CEP/TDM Bit-Rate (0x07).................................9 
     7.2. CESoPSN Interface Parameters Update Mechanism Reference....10 
     7.3. Control Plane..............................................10 
     7.4. Data Plane.................................................11 
   8. MS-PW Applicability............................................11 
   9. Pseudowire Update Backward Compatibility.......................11 
   10. Security Considerations.......................................12 
   11. IANA Considerations...........................................12 
     11.1. LDP TLV Type..............................................12 
     11.2. LDP PW Update Codes.......................................12 
   12. Acknowledgments...............................................12 
   13. References....................................................13 
     13.1. Normative References......................................13 
     13.2. Informative References....................................13 
    
    
    
    
    
    
    
    
    

 
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1. Terminology 
    
   The document uses terminology defined in [RFC4447], [PW TDM CTRL]. 
    
2. Introduction 
    
   This draft aims at providing a generic solution for on-the-fly 
   updating of PW characteristics (interface parameters, PW label) 
   without service interruption.  
   Section 5 specifies a new LDP TYPE TLV, PW Update sub-TLV, which is 
   used to advertise the parameters (interface parameters, label..) to 
   be changed.  
   Section 6 defines the related signaling extension and describes the 
   procedures to update dynamically the PW characteristics. 
   Section 7 provides an example use-case, for CESoPSN PWs. 
     
3. Motivation 
    
   The specification of a PW update mechanism is motivated by the need 
   to update a PW parameters, while avoiding service disruption. That 
   is particularly valuable for voice service applications, for 
   example, mobile backhauling. Although interface parameter update 
   will generally be a rare event for most applications, it is still 
   highly recommended not to negatively impact customer services. This 
   is even truer when the number of customers already in use is 
   significant. 
    
   Alternatives to PW parameter update are available when facing 
   traffic evolution. For instance, it would be possible to setup a new 
   PW dedicated to handle the traffic overload. However, this scenario 
   does not scale since each update would result in setting up a new 
   PW, leading to management fragmentation.   
    
4. Overview of the solution 
    
    
   The proposed solution is only applicable to the Generalized PWid FEC 
   element. This is because we desire to change some of the interface 
   parameters while keeping the same PW FEC element. Note that the PWid 
   FEC element described in [RFC4447] includes the interface parameters 
   and so does not allow maintaining the FEC. The update mechanism with 
   PWid FEC element is left for further study. 
    
    








 
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           |<-------------- Emulated Service ---------------->| 
           |                                                  | 
           |          |<------- Pseudowire ------->|          | 
           |          |                            |          | 
           |Attachment|    |<-- PSN Tunnel -->|    |Attachment| 
           |  Circuit V    V                  V    V  Circuit | 
           V   (AC)   +----+                  +----+   (AC)   V 
     +-----+    |     | PE1|==================| PE2|     |    +-----+ 
     |     |    |     |    |                  |    |     |    |     | 
     | CE1 |----------|............PW1.............|----------| CE2 | 
     |     |          |    |                  |    |          |     | 
     +-----+          |    |==================|    |          +-----+ 
                      +----+                  +----+         
                         LLM (FEC1, L1, int. Par.) 
                        -----------------------> 
                         LLM (FEC1, L2, int. Par.) 
                        <-----------------------                
                                      

                         Figure 1 Reference Model 

    
   Referring to Figure 1, PE1 is assumed as the ingress PE, and so 
   initiates the first LDP Label Mapping (LLM) message. PE2 is assumed 
   as the egress PE. The interface parameters included in the LLM 
   message allow the egress PE to be informed of the payload format 
   used by the ingress PE. The egress PE forwards the payload received 
   from CE2 in the appropriate format with the PW Label L1 to the 
   ingress PE. The Label L1 carries the (forwarding) semantics for the 
   ingress PE to correctly forward the traffic to CE1 over its local 
   AC. The same process applies in the reverse direction for the 
   traffic from the ingress PE to the egress PE.  
    
   Let's assume that some time after CE1 and CE2 have been in 
   communications, the need arises to change the traffic bandwidth. 
   This warrants a mechanism whereby operator can adjust the PW 
   capacity without incurring service disruption. We describe below how 
   the sequence of events at the control plane and data plane is 
   coordinated to bring about this capacity adjustment with no service 
   disruption. The concept employed is "make-before-break".  
    
    
   Control plane: The method consists of re-advertising the new 
   interface parameters in a new LLM message. The LLM message may also 
   carry a new label in addition to the updated interface parameters 
   for the same PW FEC element. A new LDP TLV Type is defined to 
   identify the update purpose of this LLM message, since otherwise the 
   new mapping of an already advertised FEC would be rejected. The PW 
   Update sub-TLV is included in the LLM message with the interface 
   parameters codes that are changed. The receiving PE verifies the 
   updates and acknowledges the acceptance by reciprocating the LLM 
   message to the sender.  
 
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   Note that if the If asymmetric parameters are allowed such that 
   egress PE2 does not need to increase the b/w then there is no need 
   to acknowledge the acceptance. LLM messages are assumed accepted 
   unless corresponding LDP label release is received. 
    
   Data plane: Upon reception of the new LLM message the egress PE 
   sends the traffic in the new format while initiating the new LLM 
   message for the reverse direction. Note that the possible new 
   assigned Label is required to allow the ingress PE to detect in-band 
   the traffic corresponding to the new format. Therefore the ingress 
   PE is capable of forwarding traffic correctly over its local AC in 
   its new format, since it recognizes the new Label it assigned and 
   previously advertised.        
    
5. PW Update LDP TYPE TLV 
    
   The PW Update LDP sub-TLV is included in the LLM message to identify 
   its update role, thus allowing the receiving PE to accept the new 
   interface parameters and also the possible new Label required for 
   the in-band detection. 
   The PW Update sub-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   
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+  
    |1|0|   PW Update Type (0x096D)|          Length                | 
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--++  
    |                          Update Code                          |  
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
                        
                        Figure 2 PW Update sub-TLV 


   U = 1 F= 0 implies that a legacy PE must silently discard the TLV. 
    
   The PW Update sub-TLV MUST be included in the Label Mapping message 
   generated by a PE to update some PW characteristics. 
    
   The TLV information length field contains the length of the update 
   code, namely the number of parameters to be updated in octets. Hence 
   the number of parameters to be changed included in the PW Update is 
   deduced from this field. 
    
   The Update Code indicates the parameters that must be updated. Two 
   update code are identified for the purpose of this document 
   (interface parameters iP, PW Label L). 
    
   (IANA assignment required). 
    
    


 
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   The PW Update sub-TLV is carried as follows in the Label Mapping 
   message: 
     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 
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    |                                                               | 
    +                       Generalized ID FEC                      + 
    |                                                               | 
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    |                          PW Update TLV                        | 
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    |                       Interface Parameters                    | 
    |                              "                                | 
    |                              "                                | 
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    |0|0| Generic Label (0x0200)    |      Length                   | 
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    |                             Label                             | 
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
                     Figure 3 PW Update sub-TLV in LLM 

    
   Note that the new values of the PW interface parameters defined in 
   [RFC4446] are indicated in the classic fields (i.e. the Interface 
   parameters sub-TLV as defined in [RFC4447]).    
    
6. Generic PW Capacity Update 
    
  6.1. Update Procedure 
    
   Two possible scenarios are possible when the PW capacity is 
   renegotiated, i.e. increase or decrease the PW capacity via the 
   interface parameters. The operator must take care to configure the 
   new interface parameters while not impacting existing services. The 
   update procedure must apply as follows: 
    
   - Increase the PW capacity:  
   Step1: Negotiate the new interface parameters at the both PW 
   endpoints (ingress and egress PE) according to the procedure 
   described in this document. 
   Step2: Configure on CEs the new payload related to the new interface 
   parameters. 
    
   - Decrease the PW capacity:  
   Step1: Configure on CEs the new payload related to the new interface 
   parameters. 
   Step2: Negotiate the new interface parameters at the both PW 
   endpoints (PE1, PE2) according to the procedure described in this 
   document. 
    
    
 
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  6.2. PW Update Mechanism Reference Model 
    
                     +----+                  +----+          
    +-----+          | PE1|==================| PE2|          +-----+ 
    |     |          |    |                  |    |          |     | 
    | CE1 |----------|............PW1.............|----------| CE2 | 
    |     |          |    |                  |    |          |     | 
    +-----+          |    |==================|    |          +-----+ 
                     +----+                  +----+         
        F1->      LLM (FEC1, L1, int. Par. [iP1,iP2])       <-F1     
                       ----------------------> 
                  LLM (FEC1, L2, int. Par. [iP1,iP2]) 
                       <-----------------------  
                         
                        ==========L2==========> 
                         
                        <=========L1=========== 
                                   . 
                                   .   
       LLM (FEC1, L10, Update (iP, L), new int. Par. [iP1, iP2new]) 
                       -----------------------. 
                        <=========L10========== 
       LLM (FEC1, L20, Update (iP, L), new int. Par. [iP1, iP2new]) 
                        <----------------------- 
                         =========L20=========> 
          F2->                                             <-F2  
                                      
               Figure 4 PW Update Mechanism Reference Model 
    
    

   Figure 4 depicts the procedure to update PW interface parameters and 
   the PW label. Initially PE1, the ingress PE and egress PE has a PW 
   setup with two interface parameters iP1 and iP2 that defines how the 
   traffic received from the attached CEs must be forwarded over the PW.  

   CE1 and CE2 are sending traffic in a payload format F1.  
     
   Note that the mechanism reference provides the most challenging case 
   where interface parameters and PW label must be both updated. Some 
   use cases may require only to change the PW label or only to change 
   some PW interface parameters. 
    
    
  6.3. Control Plane 
    
   Referring to Figure 4, after the operator configures a new value 
   P2new for the interface parameter (iP2), the ingress PE sends an 
   "update" LLM message to indicate the new PW parameters to the egress 
   PE. The LLM message includes the PW Update sub-TLV that specifies 
   that the interface parameters and the Label must be updated. The LLM 
   message contains a new Label L10. 
 
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   Upon reception of the LLM message the egress PE checks the presence 
   of the PW Update sub-TLV. If the PW Update sub-TLV is included in the 
   LLM message, the egress PE carries on the process by responding to 
   the ingress PE with a new LMM message as described in [RFC4447] with 
   the new interface parameter iP2 and a new Label L20. The value of 
   this new interface parameter correspond to the one learnt from the 
   LLM message received from the ingress PE.  
    
   The interface parameters could be different and configured by the 
   operator at the ingress/egress PE for asymmetrical traffic. 
    
    
  6.4. Data Plane 
    
   Referring to Figure 4, after checking the presence of the PW Update 
   sub-TLV, the egress PE updates its PW-to-Label bindings with the 
   newly assigned Label L10. This Label is associated to the new format 
   defined by [iP1,iP2new] of the PW packet. The egress PE changes over 
   the traffic received from CE2 to the new format [iP1, iP2new] with 
   the new Label L10 thus deprecating the use of older format [iP1, iP2] 
   with label L2. This new Label assignment allows in-band detection. 
   Indeed, the ingress PE identifies the Label L10 and hence deduces the 
   associated format. This in-band detection is essential to allow it to 
   restitute correctly the traffic over its AC. That is particularly 
   required when the length field of the PW header is not sufficient to 
   correctly forward the traffic to the AC (e.g. CESoPSN PW). 
    
   The same procedure applies for the reverse direction. 
    
   Figure 4 corresponds to the "increase PW capacity" case since CE1 and 
   CE2 here send the new payload format F2 once the PW has been updated. 
    
   Note that the requirement to update the interface parameters without 
   any service disruption implies that each direction of the PW must 
   follow the procedure separately. This means that for some duration of 
   time during the update process, traffic from the egress PE to the 
   ingress PE may be in the new format, while traffic in the reverse 
   direction remains in the previous format.   
    
    
7. Use Case: CESoPSN 
    
   The need to update interface parameters without service interruption 
   is particularly relevant for CESoPSN PWs. CESoPSN PWs carry TDM 
   traffic in a structure-aware fashion, with explicit specification of 
   the PW capacity (in multiples of 64 kbps). When using CESoPSN PWs, 
   there is an inherent trade-off between bandwidth consumption and 
   latency. It is thus very important to carefully match the capacity to 
   the actual payload.  
    
    

 
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   CESoPSN PWs are frequently used to encapsulate traffic in the mobile 
   backhauling architectures. When setting up such backhauling PWs the 
   needed capacity is known, but when growing the network the capacity 
   of particular PWs needs to grow without interrupting ongoing voice 
   services used by numerous customers.   
    
    
  7.1. Interface Parameters for CESoPSN PWs 
    
   This section refers to [PW TDM CTRL]. 
    
    
    7.1.1. CEP/TDM Payload Bytes (0x04) 
    
   The interface parameter CEP/TDM Payload Bytes (0x04) (P) is defined 
   in [PW TDM CTRL] for a set of TDM PW types including SAToP. For 
   CESoPSN PWs, The specified value P MUST be an integer multiple factor 
   of N, where N is the number of timeslots in the attachment circuit. 
    
    
    7.1.2. CEP/TDM Bit-Rate (0x07) 
    
   For all kinds of structure-aware emulation, this parameter MUST be 
   set to N where N is the number of DS0 channels in the corresponding 
   attachment circuit that must be retrieved from the E1 frames and 
   must be transported over the CESoPSN PW.  
    
   Note that the number of frames to be encapsulated per PW packet is 
   derived from the value (P) and (N). 
    
   Packetization latency, number of timeslots and payload size are 
   linked by the following obvious relationship: 
     
         L = 8*N*D 
     
    where: 
         o  D is packetization latency, milliseconds 
         o  L is packet payload size, octets 
         o  N is number of DS0 channels.  
    
   The payload corresponding to the value N are selected from the E1 
   frames, so as the CEP/TDM Payload Bytes (P) defined in [PW TDM CTRL] 
   corresponds to the value L multiplied by a number of E1 frames to be 
   encapsulated over the CESoPSN PW. 
    
    
    
    
    
    
    

 
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  7.2. CESoPSN Interface Parameters Update Mechanism Reference Model 
    
    
                     +----+                  +----+          
    +-----+          | PE1|==================| PE2|          +-----+ 
    |     |          |    |                  |    |          |     | 
    | CE1 |----------|............PW1.............|----------| CE2 | 
    |     |          |    |                  |    |          |     | 
    +-----+          |    |==================|    |          +-----+ 
                     +----+                  +----+         
          N1->      LLM (FEC1, L1, int. Par. [N1, P1])     <-N1     
                       ----------------------> 
                    LLM (FEC1, L2, int. Par. [N1, P1]) 
                       <-----------------------  
                         
                        ==========L2==========> 
                         
                        <=========L1=========== 
                                   . 
                                   .   
         LLM (FEC1, L10, Update (iP, L), new int. Par. [N2, P2]) 
                       -----------------------. 
                        <=========L10========== 
         LLM (FEC1, L20, Update (iP, L), new int. Par. [N2, P2]) 
                        <----------------------- 
                         =========L20=========> 
          N2->                                             <-N2  
    
           Figure 5 CESoPSN PW Update Mechanism Reference Model 
    
    
   Figure 5 depicts the procedure to update CESoPSN interface 
   parameters. Initially PE1, the ingress PE is assumed to setup a 
   CESoPSN PW with PE2, the egress PE with the two interface parameters 
   (N, P) defined in section 7.1.1, 7.1.2.  
    
   CE1 and CE2 are sending E1 frames with N1 timeslots payload. 
    
   The ingress PE picks the N1 timeslots from E1 frames to reach a 
   total payload of (P), encapsulates them in a PW packet and forwards 
   the PW packet to the ingress PE with Label L2. 
    
    
    
  7.3. Control Plane 
    
   Referring to Figure 5, after the operator configures the new 
   interface parameters (N2, P2), the ingress PE initiates a new LLM 
   message to indicate them to the egress PE. The LLM message includes 
   the PW Update sub-TLV which specifies the parameters to be updated 
   (interface parameter iP, PW Label L). The LLM message contains the 
   new interface paramters'value and the new Label L10.  
 
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   Upon reception of the LLM message the egress PE checks the presence 
   of the PW Update sub-TLV. Since the PW Update sub-TLV is included in 
   the LLM message, the egress PE carries on the process by responding 
   to the ingress PE with a new LMM message as described in [RFC4447] 
   with the new interface parameters and a new Label L20. 
    
  7.4. Data Plane 
    
   Referring to Figure 5, after checking the presence of the PW Update 
   sub-TLV, the egress PE updates its PW-to-Label bindings with the new 
   assigned Label L10. This Label is associated to the new format 
   defined by [N, P] of the PW packet. The egress PE switches the 
   traffic received from CE2 from PW1 in the previous format [N1, P1] 
   with the Label L1 to PW1 in the new format [N2, P2] with the new 
   Label L10. This new Label assignment allows in-band detection. Indeed 
   the ingress PE identifies the Label L10 and hence deduces the 
   associated format. This in-band detection is essential to allow it to 
   restitute correctly the traffic over its AC.  
    
   The same procedure applies for the reverse direction. 
    
   Figure 5 corresponds to the "increase PW capacity" case since CE1 and 
   CE2 here send the new payload (N2 timeslots payload per E1 frames) 
   once the PW has been updated. 
    
   Note that the procedure assumes that some empty payload is 
   encapsulated per PW packet between the both steps.   
    
    
8. MS-PW Applicability 
    
   The PW update mechanism applies in an MS-PW environment as described 
   in [MS-PW ARCH]. 
    
   The S-PEs must accept the new assigned Label, so must also be 
   capable to interpret the PW Update sub-TLV. The S-PEs must initiate 
   new LLM messages to the next hop with the new interface parameters 
   received from the ingress T-PE. These messages must contain a new PW 
   Label, so must also include the PW Update sub-TLV.  
    
   This section will be completed with more detail in a future version. 
    
9. Pseudowire Update Backward Compatibility 
    
   TBD: in this draft a new capability bit, following procedures 
   defined in draft-thomas-mpls-ldp-capabilities-01.txt 
   With regards to Figure 4, since the ingress PE initiates the LLM 
   message, it MUST specify the PW Update sub-TLV without any Update 
   Code in the initial message in order to negotiate it with the egress 
   PE. 
    
 
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   When the egress PE receives the LLM message from the ingress PE, if 
   it supports the PW Update sub-TLV, at turn it MUST include it in the 
   LLM message in response to the initial message.  
    
   If the egress PE does not support the PW Update sub-TLV, it will 
   silently discard the sub-TLV as the U bit is set and the F bit is 
   cleared and will continue to perform the PW setup by initiating a 
   LLM message to the ingress PE. 
    
   In that case the egress PE sends a LLM message to the ingress PE 
   without the PW Update sub-TLV. The absence of this sub-TLV informs 
   the ingress PE that the egress PE is not capable to deal with the PW 
   Update sub-TLV. 
    
10. Security Considerations 
    
   This security considerations of RFC4447 apply here as well. 
    
11. IANA Considerations 
    
   Most of the IANA assignments required by this draft are already 
   listed in [RFC4446].  
    
  11.1. LDP TLV Type 
    
   This document uses a new LDP TLV types; IANA already maintains a 
   registry of name "TLV TYPE NAME SPACE" defined by RFC 3036. The 
   following values are suggested for assignment: 
    
   Sub-TLV PW Update 
    
    
  11.2. LDP PW Update Codes 
    
   This document proposes the definition of two new LDP PW Update codes 
   corresponding to the interface parameters and to the PW label 
   change. 
    
   The following values are suggested for assignment: 
    
      Range/Value     E     Description                       Reference 
      ------------- -----   ----------------------            --------- 
    
12. Acknowledgments 
    
   This draft borrows from concepts developed by Himanshu Shah in an 
   earlier draft entitled "Dynamic Parameters Signaling for MPLS-based 
   Pseudowires". 
    
    
    

 
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13. References 

    
  13.1. Normative References 
    
[RFC2119]       Bradner, S., "Key words for use in RFCs to Indicate 
                Requirement Levels", BCP 14, March 1997. 
 
[RFC4234]       Crocker, D. and Overell, P.(Editors), "Augmented BNF 
                for Syntax Specifications: ABNF", Internet Mail 
                Consortium and Demon Internet Ltd., November 1997. 
 
[RFC4446]       Martini, L., "IANA Allocations for Pseudowire Edge to 
                Edge Emulation (PWE3)", April 2006 
 
[RFC4447]       El-Aawar, N., Heron, G., Martini, L., Smith, T., Rosen, 
                E., "Pseudowire Setup and Maintenance Using the Label 
                Distribution Protocol (LDP)", April 2006 
 

 
 
  13.2. Informative References 
    
[PW TDM CTRL]     Stein, Y., Vainshtein, A., "Control Protocol 
                  Extensions for Setup of TDM Pseudowires", Internet 
                  Draft, draft-ietf-pwe3-tdm-control-extensi-04.txt, 
                  March 2008 

[MS-PW ARCH]      Bocci, M., and Bryant, S.,T., "An Architecture for 
                  Multi-Segment Pseudo Wire Emulation Edge-to-Edge", 
                  Internet Draft, draft-ietf-pwe3-ms-pw-arch-03.txt, 
                  October 2006 

[PWE3 CESoPSN]    Vainstein, A, and al., "Structure-aware TDM Circuit 
                  Emulation Service over Packet Switched Network 
                  (CESoPSN)", Internet Draft, draft-ietf-pwe3-cesopsn-
                  07, LC 
                  

    
Author's Addresses 
    
   Frederic Jounay   
   France Telecom   
   2, avenue Pierre-Marzin   
   22307 Lannion Cedex   
   FRANCE  
   Email: frederic.jounay@orange-ftgroup.com 

    
 
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   Philippe Niger   
   France Telecom   
   2, avenue Pierre-Marzin   
   22307 Lannion Cedex   
   FRANCE  
   Email: philippe.niger@orange-ftgroup.com 
    
   Yaakov (Jonathan) Stein 
   RAD Data Communications 
   24 Raoul Wallenberg St., Bldg C 
   Tel Aviv  69719 
   ISRAEL 
   Email: yaakov_s@rad.com 
    
   Himanshu Shah 
   Ciena Corp 
   35 Nagog Park 
   Acton, MA 01720 
   USA 
   Email: hshah@ciena.com 
    
    
    
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