Internet DRAFT - draft-mda-mpls-tp-p2mp-oam-framework

draft-mda-mpls-tp-p2mp-oam-framework



MPLS Working Group                                          K.Arai, Ed. 
                                                                 H.Date 
                                                             M.Murakami 
                                                                    NTT 
Internet Draft                                                  W.Cheng 
                                                                   CMCC 
                                                                      
Intended status: Informational     
                                                                      
                                                                       
                                                                       
                                                                      
                                                                      
 
Expires: October 2, 2015                                March 31, 2015 
                                   
 
               Framework for Point-to-Multipoint MPLS-TP OAM 
                draft-mda-mpls-tp-p2mp-oam-framework-01.txt 


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Copyright Notice 

   Copyright (c) 2015 IETF Trust and the persons identified as the 
   document authors. All rights reserved. 
 
 
 
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   This document is subject to BCP 78 and the IETF Trust's Legal 
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   publication of this document. Please review these documents 
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Abstract 

   The MPLS transport profile (MPLS-TP) is being standardized to enable 
   carrier-grade packet transport.  

   This document discusses and specifies the P2MP framework primarily 
   related to OAM and related management in MPLS-TP networks. This 
   document mainly refers to RFC5654 and RFC6371. The main focus is on 
   the details that are not covered or not clarified in relevant RFCs 
   such as RFC5654, RFC5860, RFC5921, RFC5951, RFC6371, and RFC7167. 

   Note: This I-D was made and updated including the discussions in 
   ITU-T SG15, which were described in Liaison Statements such as 
   (https://datatracker.ietf.org/liaison/1235/) 

   This document is a product of a joint Internet Engineering Task 
   Force (IETF) / International Telecommunications Union 
   Telecommunications Standardization Sector (ITU-T) effort to include 
   an MPLS Transport Profile within the IETF MPLS and PWE3 
   architectures to support the capabilities and functionalities of a 
   packet transport network. 

    

Table of Contents 

    
   1. Introduction ................................................ 3 
   2. Conventions used in this document............................ 4 
      2.1. Terminology ............................................ 4 
      2.2. Definitions ............................................ 5 
   3. P2MP OAM and management...................................... 5 
      3.1. General aspects of architecture ........................ 5 
 
 
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         3.1.1. Return path ........................................ 5 
         3.1.2. M-leaves management scenario in P2MP path........... 6 
         3.1.3. Refinement of existing requirements on P2MP transport 
         path  ..................................................... 7 
         3.1.4. Addition and removal of branch tree in P2MP transport 
         path  ..................................................... 8 
      3.2. General aspects of P2MP OAM ............................. 8 
      3.3. OAM functions for proactive monitoring ................. 11 
         3.3.1. Continuity Check and Connectivity Verification(CC-V)11 
         3.3.2. Remote Defect Indication .......................... 12 
         3.3.3. Alarm Reporting ................................... 12 
         3.3.4. Lock Reporting .................................... 12 
         3.3.5. Packet Loss Measurement ........................... 12 
         3.3.6. Packet Delay Measurement .......................... 12 
         3.3.7. Client Failure Indication ......................... 12 
      3.4. OAM functions for on-demand monitoring ................. 12 
         3.4.1. Connectivity verification ......................... 12 
         3.4.2. Packet loss measurement ........................... 13 
         3.4.3. Diagnostic tests .................................. 13 
         3.4.4. Route Tracing ..................................... 13 
         3.4.5. Packet delay measurement .......................... 13 
      3.5. OAM functions for administration control ............... 13 
         3.5.1. Lock Instruct ..................................... 13 
   4. Layer Models ................................................ 14 
   5. Applicable Scenarios ........................................ 15 
   6. Security Considerations ..................................... 15 
   7. IANA Considerations ......................................... 15 
   8. References .................................................. 15 
      8.1. Normative References ................................... 15 
      8.2. Informative References ................................. 15 
   9. Acknowledgments ............................................. 15 
    
1. Introduction 

   The demand for P2MP traffic is expected to quickly increase due to 
   the increase in new services such as IP-TV,compressed & uncompressed 
   video distribution, and smart TV. In light of the global trend in 
   improving energy efficiency as well as general network cost 
   reduction, a point-to-multipoint (P2MP) transport function in MPLS-
   TP could be one of the solutions for providing these services from 
   the perspective of efficient use of network resources.  

   RFC5654[1] defines the following requirements that are specific to 
   P2MP. 



 
 
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   - Traffic-engineered point-to-multipoint (P2MP) transport 
   paths.(item 6). 
   - Unidirectional point-to-multipoint(P2MP) transport paths (item 8) 
   - Being capable of using P2MP server (sub)layer capabilities when 
   supporting P2MP MPLS-TP transport paths(item 40) 
   - The MPLS-TP control plane MUST support establishing all the 
   connectivity patterns defined for the MPLS-TP data plane (i.e. 
   unidirectional P2MP) including the configuration of protection 
   functions and any associated maintenance functions.(item 50) 
   - Unidirectional 1+1 protection for P2MP connectivity (item 65 C) 
   - Unidirectional 1:n protection for P2MP connectivity(item 67 B) 
   - MPLS-TP recovery in a ring MUST protect unidirectional P2MP        
   transport paths.(item 95) 
    

   RFC5860 [2] defines MPLS-TP OAM requirements including those for 
   unidirectional P2MP transport paths. With a unidirectional P2MP 
   transport path, two cases are assumed as per Section 3.3 of 
   RFC6371[3]. One is when no return path exists or not used and the 
   other is when an "out-of-band" return path exists and used.  

   In I-D[4], only a summary of various items specific to MPLS-TP P2MP 
   framework. For example, according to the editor's note, this section 
   will contain a summary of P2MP OAM, as described in RFC6371 [3], 
   which defines the overall OAM architecture for MPLS-TP. 
    
   Therefore, this draft intends to specify details of a P2MP framework 
   that complements P2MP requirements and the framework of existing 
   RFCs, particularly in terms of OAM, management, and recovery. 
    
   Note: MPLS-TP functions that are applicable specifically to P2MP 
   transport paths are outside the scope of RFC5921.  
    
2. 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 [1].  

  2.1. Terminology 

    

   EMS  Element management system 

   LSP  Label Switched Path 

 
 
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   NE   Network Element 

   NMS  Network Management System 

    

  2.2. Definitions 

   None  

    

3. P2MP OAM and management 

  3.1. General aspects of architecture 

3.1.1. Return path 

   The support of P2MP OAM on the data path should be independent of 
   the availability of a return path or the mechanism that supports the 
   return path. Basically, only unidirectional P2MP is supported in 
   MPLS-TP. This means that an "in-band" return path is out of the 
   scope of MPLS-TP requirements. In this section, two cases, with out-
   band return path and without return path, are considered basic and 
   the requirements that should be met when return paths exist should 
   be independently specified in other document, if needed.  

   P2MP considerations are described in Section 3.7 of RFC6371. The RFC 
   has already described some requirements with out-band return path(s). 
   On the other hand, even if there is no return path, most OAM 
   requirements in RFC5860 can be met by supporting the management 
   interface through which EMS/NMS can retrieve the received OAM 
   packets.  

   The "return path" may be considered to be directed to the entity 
   that originally requested the measurements because this may not be 
   the head end of the P2MP connection. Therefore, the following return 
   path should be distinctly differentiated. 

      RP-N: A return path to the EMS/NMS through the management 
      interface (RP-N) (this case is referred to as that in which no 
      return path exists) 

      RP-HE: A return path to a head end (root) of a P2MP path using any 
      kind of out-of-band path (this case is referred to as that in 
      which an out-of-band return path exists) 

 
 
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   The interpretation of return path usually corresponds to RP-HE. 
   These two kinds of return paths may be applied at the same time, 
   depending on the situations.  

3.1.2. M-leaves management scenario in P2MP path 

   Generally, a function to monitor only the subset leaves of a P2MP 
   transport path is required to appropriately monitor the status of 
   P2MP transport paths. The supplemental requirements are as follows. 

   1) M-leaves management, which enables NMS to perform OAM functions 
        at a set of leaves on a P2MP transport path, must be supported.  

   2) M-leaves must be selectable by the operator or administrator 
        using NMS. 

   3) M-leaves management should be independently enabled/disabled in 
        each OAM function.  

   4) In M-leave monitoring, one scenario should be selected to avoid 
        future interoperability problems between related entities (NE, 
        EMS, and NMS). 

   There are four scenarios considered in MPLS-TP networks that consist 
   of NEs, EMS, and NMS. 

   In scenario 1, OAM protocol extension is necessary. OAM packets sent 
   from the source MEP must include a subset of leaf-MEPs. A sink MEP 
   determines if it should be notified of the management process within 
   an NE based on the leaf-IDs included in the OAM packet. However, 
   this is not supported in RFC6371. 

   In scenario 2, OAM packets that are supported in RFC6371 and are 
   targeted at all leaves can be utilized. As a result, no extension is 
   necessary in the P2MP OAM protocol. On the other hand, a subset of 
   M-leave/sink MEPs must be configured at an EMS from an NMS. In 
   addition, a pre-configuration of a subset of M-leave/sink MEPs is 
   needed at related NEs from the EMS. Only the notification-enabled M-
   leaves/nodes notify the EMS of its monitoring results. 

   In scenario 3, OAM packets that are supported in RFC6371 and are 
   targeted at all leaves can also be utilized. There is no P2MP OAM 
   protocol extension. On the other hand, NMS configuration on M-
   leaves/sink MEPs is needed. In addition, a subset of M-leave/sink 
   MEPs must be configured at the EMS from the NMS. However, no pre-
   configuration of a subset of M-leaves/NEs is needed. 

 
 
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   In scenario 4, OAM packets that are supported in RFC6371 and are 
   targeted at all leaves can also be utilized. There is no P2MP OAM 
   protocol extension. Only NMS configuration on M-leaves/sink MEPs is 
   needed. A configuration of a subset of M-leave/sink MEPs at the EMS 
   from the NMS is not necessary. No pre-configuration of a subset of 
   M-leaves/NEs is needed. 

   Considering some negative impacts such as the efficient use of a 
   data communication network (DCN), insufficient manageability of 
   network element (NE), traffic congestion at EMS/NMS, and heavy load 
   for OAM packet processes at EMS/NMS,  scenario 2 is required in 
   MPLS-TP p2mp network. 

3.1.3. Refinement of existing requirements on P2MP transport path 

   MPLS-TP RFCs are sufficiently mature in terms of the requirements 
   and framework of MPLS-TP P2P. On the other hand, in terms of MPLS-TP 
   P2MP, some parts of MPLS-TP RFCs and Recommendations could be 
   refined and clarified. 

   (R1) CV requirement of RFC5860 

   CV is ambiguously defined in RFC5860 "MPLS-TP OAM requirement". 
   According to this definition of RFC5860, it seems to be source-MEP 
   oriented and not correct in P2MP.  

   Current text: The MPLS-TP OAM toolset MUST provide a function to 
   enable an End Point to determine whether or not it is connected to 
   specific End Point(s) by means of the expected PW, LSP, or Section. 

   In unidirectional P2MP, the source MEP cannot determine whether or 
   not it is connected to specific End Point(s). Therefore, in P2MP, 
   the definition of connectivity verification should be corrected in 
   P2MP framework draft and OAM Recommendation as follows. 

   Proposed text: The MPLS-TP OAM toolset MUST provide a function to 
   enable a sink End Point to determine whether or not it is connected 
   to a specific source End Point by means of the expected PW or LSP. 

   (R2) CC Requirement of RFC6371 

   According to RFC6371, it is assumed that CC means that CC OAM packet 
   does not include either a source MEP or destination MEP. Only 
   unidirectional P2MP is supported in MPLS-TP, so the continuity of 
   the CC OAM packets are received by sink MEPs, and a sink MEP should 
   notify the equipment fault management process of the detected defect. 
   However, the following current text doesn't correctly describe the 
 
 
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   unidirectional feature that is specific to P2MP transport path. 
   Therefore, the requirement should be modified.  

   Current text in RFC: Proactive Continuity Check functions, as 
   required in Section 2.2.2 of RFC 5860 [11], are used to detect a 
   loss of continuity (LOC) defect between two MEPs in an MEG. 
   Proactive Connectivity Verification functions, as required in 
   Section 2.2.3 of RFC 5860 [11], are used to detect an unexpected 
   connectivity defect between two MEGs (e.g., mismerging or 
   misconnection), as well as unexpected connectivity within the MEG 
   with an unexpected MEP. 

   Proposed text: Proactive Continuity Check functions, as required in 
   Section 2.2.2 of RFC5860, are used to detect a loss of continuity 
   (LOC) defect from the source MEP to sink MEP(s). Proactive 
   Connectivity Verification functions, as required in Section 2.2.3 of 
   RFC5860, are used to detect an unexpected connectivity defect from 
   the source MEP to sink MEP(s) (e.g., mismerging or misconnection), 
   as well as unexpected connectivity within MEG with an unexpected 
   source MEP. 

   (R3) Optional requirements on CC-V OAM packets 

   In a P2MP transport path, it is highly desirable that in order to 
   save OAM bandwidth consumption, CV, when used, be linked with CC 
   into CC-V OAM packets. 

3.1.4. Addition and removal of branch tree in P2MP transport path 

   When additional branches, in other words, additional destination NEs 
   (leaves) need to be added to an existing transport path after a 
   connection service is provided via the P2MP path, an operator must 
   be capable of adding a new branch tree to the P2MP transport path 
   flexibly from any point on the path without service interruption. 
   The reason is that merging and crossover of the P2MP LSP branch tree 
   must be rejected because it is not efficient in terms of network 
   resources. As a result, the following requirement must be supported 
   in the MPLS-TP P2MP transport path. 

  3.2. General aspects of P2MP OAM 

   P2MP transport paths are unidirectional; therefore, there is 
   generally no in-band return path as in the MPLS-TP transport path 
   per se. However, there are basically two approaches for handling OAM 
   requirements in P2MP MPLS-TP.  


 
 
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   The first one is used to report the results of the 
   monitoring/measurement of OAM packets from the OAM target node to 
   the EMS/NMS when the NMS usually instantiates OAM functions and 
   requires the results of OAM monitoring functions. This approach is 
   called RP-N. The second approach is the return path to a root 
   (source MEP) of a P2MP path using different methods such as a 
   unidirectional p2p transport paths, and other technology-layers, 
   such as IP, Ethernet, and OTN, when an NE within which a root MEP 
   resides instantiates OAM functions or receive results of OAM 
   monitoring functions. This approach is called as RP-HE. The 
   following requirements are supported in terms of network elements 
   when considering RP-N. 

   1. OAM functions of a MEG of a P2MP transport path should be 
      configurable using the EMS/NMS.  

   2. Source nodes at which the source MEP reside and OAM packets are 
      generated should receive OAM related information such as 
      enabling/disabling OAM functions and setting/changing OAM 
      attributes from the EMS/NMS on a P2MP transport path. 

   3. Sink nodes at which targeting MIPs or MEPs reside and OAM packets 
      are parsed should report OAM related information such as OAM 
      monitoring results and consequent OAM actions to the EMS/NMS. 

   4. Each OAM function of a P2MP transport path should be able to be 
      independently configured using the EMS/NMS based on the 
      classification of OAM functional requirements in RFC5860.  

   5. An on-demand OAM function must be able to perform an OAM function 
      for only a specific target MIP or MEP as well as all MEPs in a 
      P2MP transport path, as specified in Section 3.7 of RFC6371[3]. 

   6. To manage M leaves(i.e., subset of all leaves) in an on-demand OAM 
      function from the EMS/NMS, a unified mechanism must be provided.  

      Note: Currently, sending an OAM packet that is targeted at a 
      subset of M leaves by using an aggregating mechanism such as an 
      OAM packet including several MIP or MEP identifiers is out of the 
      scope of RFC6371[3] as described in Section 3.7 of that document. 

   7. Mismatches of configuration information between a root MEP and any 
      leaf-MEP, at which proactive or on-demand monitoring is enabled, 
      should be detected as a configuration mismatch alarm and be 
      reported to the EMS/NMS by parsing received OAM packets, 
      particularly when a static setting is applied.  

 
 
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   Generally when each OAM function is enabled, as described in Section 
   5.1 of RFC6371[3], the source MEP function should be enabled prior 
   to the corresponding sink MEPs' function.  

   Regarding configuration considerations, the following are additional 
   requirements for unidirectional P2MP transport path, particularly 
   when RP-HE does not exist. 

   8. The configuration of each OAM function between the source MEP and 
      sink MEP(s) in an MEG of a transport path should be able to be 
      synchronized using the NMS, when a new P2MP transport path is set.  

   9. OAM functions of a newly added/deleted branch transport path from 
      any point of an existing transport path must be able to be 
      configured and enabled/disabled on a newly integrated/combined 
      P2MP transport path without affecting client traffic to existing 
      end points of the P2MP transport path other than the added/removed 
      branch transport path. 

   10.The configuration of newly added/removed specific sink 
      MEP(s)to the existing source MEP in the MEG in proactive 
      monitoring should be able to be synchronized with that of the 
      source MEP by using the NMS. 

   11.The EMS/NMS should provide a tool for manually configuring 
      consistent values of each piece of configuration information to a 
      root MEP and all the related leaf MEPs in a MEG of a P2MP 
      transport path for both pro-active and on-demand OAM functions. 

   12.Mismatches of configuration information between a leaf MEP and 
      any other leaf MEP(s) or a root MEP and leaf MEP(s), at which 
      proactive monitoring will be enabled, should be able to be 
      detected through the configuration management process of the 
      EMS/NMS as a configuration mismatch alarm or notification without 
      receiving OAM packets from a source MEP(before OAM functions are 
      enabled). 

      Note: This requirement is not necessary if the EMS/NMS provides a 
      tool to manually configure a consistent value of each piece of 
      configuration information to a root MEP. 

   13.The enabling or disabling of proactive OAM functions and 
      configuration mismatch alarms of the OAM functions must be 
      independently configurable at each leaf-MEP as well as on all the 
      leaf MEPs on a P2MP transport path, considering maintenances or a 
      case in which one or more leaf MEPs is newly added or removed 
      later. 
 
 
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   14.Mismatches of configuration information between a leaf MEP and 
      any other leaf MEP(s) or a root MEP and leaf MEP(s), at which on-
      demand OAM monitoring is enabled, must be detected as a 
      configuration management process before conducting OAM functions. 

    

  3.3. OAM functions for proactive monitoring 

   The proactive OAM functions are used to detect a fault/defect or to 
   automatically reports a change in the status of a transport path. 

3.3.1. Continuity Check and Connectivity Verification(CC-V) 

   The continuity Check function enables one or more leaf MEPs on a 
   unidirectional P2MP transport path to monitor the continuity of OAM 
   packets from root MEP and detect one or more loss of continuity(LOC) 
   defects between the root MEP and leaf MEPs.  

   The connectivity verification function enables one or more leaf MEPs 
   on a P2MP transport path to monitor the connectivity of OAM packets 
   from a specific root MEP and detect an unexpected connectivity 
   defect between two MEGs(two P2MP transport paths) 

   As described in Sections 2.2.2 and 2.2.3 of RFC5860[2], CC-V MUST be 
   supported even when RP-HE does not exist. 

   As described in RFC6371[3], CC-V OAM packets are used for a P2MP 
   transport path. Defect detection mechanisms in P2MP transport paths 
   are the same as those of the P2MP transport path specified in 
   section 5.1.1 of RFC6371 [3]. That is, loss of continuity(LoC) 
   defect, mis-connectivity defect, period mis-configuration defect and 
   unexpected encapsulation defect. Entry and exit criteria are also 
   the same as those of the P2MP transport paths in RFC6371 [3]. 
   However, in a P2MP transport path, all the leaf MEPs that detect a 
   defect must be indentified and differentiated from a normal leaf 
   MEP(s), which does not detect a defect. 

   Configuration is specified in Section 5.1.3 of RFC6371[3]. The 
   following configuration information must be configured: MEG-ID, MEP-
   ID, list of the other MEPs in the MEG that are different between the 
   root MEP and leaf MEP, PHB for E-LSP and transmission rate. 

   Consequent actions of a unidirectional P2MP transport path are also 
   covered in Section 5.1.2 of RFC6371 [3]. Operators should be able to 
   enable/disable each consequent action. 

 
 
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   All MEPs inside a MEG need to be configured and retain the 
   information when a proactive OAM function is enabled, as described 
   in Section 5.1.3 of RFC6371[3]. If there is no RP-HE, it is premised 
   that the EMS/NMS exists. Therefore, the above parameters are 
   statically configured. 

    

3.3.2. Remote Defect Indication 

   This OAM function is not available on a P2MP transport path when 
   return paths do not exist. This OAM function can be implemented only 
   in RP-HE. However, the return path is out of the scope of MPLS-TP 
   requirements.  

3.3.3. Alarm Reporting 

   For further study(FFS)   

3.3.4. Lock Reporting 

   FFS 

3.3.5. Packet Loss Measurement 

   FFS 

3.3.6. Packet Delay Measurement 

   FFS 

3.3.7. Client Failure Indication 

   FFS 

  3.4. OAM functions for on-demand monitoring 

    

3.4.1. Connectivity verification 

   The connectivity verification function enables one or more leaf MEPs 
   on a P2MP transport path to monitor the connectivity of OAM packets 
   from a specific root MEP and detect an unexpected connectivity 
   defect between two MEGs (two P2MP transport paths) 


 
 
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   1. Connectivity verification functions MUST be supported when return 
      paths in a unidirectional P2MP transport path do not exist. 

   As described in RFC6371 [3], CC-V OAM packets are used for a P2MP 
   transport path. Defect detection mechanisms in P2MP transport paths 
   are the same as those of the P2MP transport path specified in 
   section 5.1 of RFC6371. That is, loss of continuity defect, mis-
   connectivity defect, period mis-configuration defect and unexpected 
   encapsulation defect. Entry and exit criteria are also the same as 
   those of the P2MP transport path in RFC6371 [3]. Moreover, 
   consequent actions of a unidirectional P2MP transport path are also 
   covered in Section 5.1.2 of the RFC [3] 

   Regarding configuration consideration, the following additional 
   requirements on a unidirectional P2MP transport path when a return 
   path does not exist. 

3.4.2. Packet loss measurement 

   FFS 

3.4.3. Diagnostic tests 

      Diagnostic test functions MUST be supported when a return path in 
      a unidirectional P2MP transport path doesn't exist. 

   Other requirements are ffs. 

3.4.4. Route Tracing 

      Route tracing function MUST be supported when a return path in a 
      unidirectional P2MP transport path doesn't exist. 

   Other requirements are ffs. 

    

3.4.5. Packet delay measurement 

   FFS 

  3.5. OAM functions for administration control 

3.5.1. Lock Instruct 

   FFS. 

 
 
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4. Layer Models 

   Generally, MPLS-TP technology consists of two technical basis: one 
   is LSP and the other is Pseudowire (PW). In PW, two types of multi-
   segment PW are supported: one is single-segment PW(SS-PW) and multi-
   segment PW(MS-SW). Considering the combination of those technologies, 
   there are a few types of combinations considered in layering models 
   of MPLS-TP. Fig.1 shows those examples. 

    
                  ------------     ------------     ------------ 
   Channel layer | P2MP SS-PW |   | P2MP MS-PW |   | P2MP MS-PW | 
                  ------------     ------------     ------------ 
   Path layer    | P2MP LSP   |   |  P2P LSP   |   | P2MP LSP   | 
                  ------------     ------------     ------------ 
   Server layer  | P2P any    |   |  P2P any   |   |  P2P any   | 
                  ------------     ------------     ------------ 
                    Model 1          Moldel 2         Model 3 
 
             Figure 1 : Examples of Layer models in P2MP MPLS-TP 

In principal, server layer is provided by any technologies such as 
Ethernet, OTN and MPLS-TP in P2P link. On the other hand, channel layer 
and path layer are provided by PW and LSP and both technologies support 
P2MP as well as P2P in current MPLS technology. From the perspective, 
three possible models are described in Fig.1.  

There are still some discussion on which model should be adopted in 
MPLS-TP. The key issue is on some ambiguity of the boundary of PW 
function and LSP function. This OAM framework draft firstly focuses on 
Model 1, in which P2MP SS-PW is applied in a channel layer and P2MP LSP 
is applied in a path layer. Model 2 and Model 3 are for further study. 
Regarding P2MP PW, as shown in [4], P2MP PW survivability has not been 
discussed yet. P2MP PW requirements are being developed in [5]. 









 
 
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5. Applicable Scenarios 

P2MP MPLS-TP LSP could be applied not only to point to multi-point 
topology networks, but also to p2mp portions which constructs multi-
point to multi-point services. OAM functions described in this document 
can be utilized for meeting those requirements. 
  
 
 
6. Security Considerations 

   This document does not raise any particular security considerations. 

7. IANA Considerations 

   There are no IANA actions required by this draft. 

8. References 

  8.1. Normative References 

   [1]  Niven-Jenkins, B., et all, "Requirements of an MPLS Transport 
         Profile", RFC5654, September 2009 

   [2]  Vigoureux, M., Betts, M., Ward, D., "Requirements for OAM in 
         MPLS Transport Networks", RFC5860, May 2010 

   [3]  Busi, I., Dave, A. , "Operations, Administration and 
         Maintenance Framework for MPLS-based Transport Networks ", 
         RFC6371, September 2011 

   [4]  Frost, Dan.,et all, "A Framework for Point-to-Multipoint MPLS 
         in Transport Networks", RFC7167, April 2014 

   [5]  Bocci, M., Heron, G., Jounay, F. and Y. Kamite, "Requirements 
         and Framework for Point-to-Multipoint Pseudowires over MPLS 
         PSNs", RFC7338, September 2014, October 2013. 

9. Acknowledgments 

   The author would like to thank all members (including MPLS-TP 
   steering committee, the Joint Working Team, the MPLS-TP Ad Hoc Group 
   in ITU-T) involved in the definition and specification of MPLS 
   Transport Profile. 

   This document was prepared using 2-Word-v2.0.template.dot. 

 
 
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Authors' Addresses 

    
   Kaoru Arai 
   NTT 
   arai.kaoru@lab.ntt.co.jp 
    
   Hiroki Date 
   NTT 
   date.hiroki@lab.ntt.co.jp 
    
   Makoto Murakami 
   NTT 
   murakami.makoto@lab.ntt.co.jp 
    
   Weiqiang Cheng 
   China Mobile 
   chengweiqiang@chinamobile.com 




























 
 
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