


 Network Working Group                                  Hing-Kam Lam 
 Internet Draft                                       Alcatel-Lucent 
 Expires: March, 2010                                Scott Mansfield 
 Intended Status: Standards Track                          Eric Gray 
                                                            Ericsson 
                                                    October 21, 2009 
                                     
                 MPLS TP Network Management Requirements 
                     draft-ietf-mpls-tp-nm-req-06.txt 


 Status of this Memo 

    This Internet-Draft is submitted to IETF in full conformance with 
    the provisions of BCP 78 and BCP 79. 

    Internet-Drafts are working documents of the Internet Engineering 
    Task Force (IETF), its areas, and its working groups.  Note that 
    other groups may also distribute working documents as Internet-
    Drafts. 

    Internet-Drafts are draft documents valid for a maximum of six 
    months and may be updated, replaced, or obsoleted by other 
    documents at any time.  It is inappropriate to use Internet-
    Drafts as reference material or to cite them other than as "work 
    in progress." 

    The list of current Internet-Drafts can be accessed at 
         http://www.ietf.org/ietf/1id-abstracts.txt 

    The list of Internet-Draft Shadow Directories can be accessed at 
         http://www.ietf.org/shadow.html 

    This Internet-Draft will expire on April 21, 2010. 

 Abstract 

    This document specifies the requirements for the management of 
    equipment used in networks supporting an MPLS Transport Profile 
    (MPLS-TP). The requirements are defined for specification of 
    network management aspects of protocol mechanisms and procedures 
    that constitute the building blocks out of which the MPLS 
    transport profile is constructed.  That is, these requirements 
    indicate what management capabilities need to be available in 
    MPLS for use in managing the MPLS-TP. This document is intended 
    to identify essential network management capabilities, not to 
    specify what functions any particular MPLS implementation 
    supports.  


  
  
  
 Gray, et al              Expires April, 2010               [Page 1]
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

 Table of Contents 

     
    1. Introduction................................................3 
       1.1. Terminology............................................4 
    2. Management Interface Requirements...........................6 
    3. Management Communication Channel (MCC) Requirements.........6 
    4. Management Communication Network (MCN) Requirements.........7 
    5. Fault Management Requirements...............................8 
       5.1. Supervision Function...................................8 
       5.2. Validation Function....................................9 
       5.3. Alarm Handling Function...............................10 
          5.3.1. Alarm Severity Assignment........................10 
          5.3.2. Alarm Suppression................................11 
          5.3.3. Alarm Reporting..................................11 
          5.3.4. Alarm Reporting Control..........................11 
    6. Configuration Management Requirements......................12 
       6.1. System Configuration..................................12 
       6.2. Control Plane Configuration...........................12 
       6.3. Path Configuration....................................12 
       6.4. Protection Configuration..............................13 
       6.5. OAM Configuration.....................................14 
    7. Performance Management Requirements........................14 
       7.1. Path Characterization Performance Metrics.............15 
       7.2. Performance Measurement Instrumentation...............16 
          7.2.1. Measurement Frequency............................16 
          7.2.2. Measurement Scope................................16 
    8. Security Management Requirements...........................17 
       8.1. Management Communication Channel Security.............17 
       8.2. Signaling Communication Channel Security..............17 
       8.3. Distributed Denial of Service.........................18 
    9. Security Considerations....................................18 
    10. IANA Considerations.......................................19 
    11. Acknowledgments...........................................19 
    12. References................................................19 
       12.1. Normative References.................................19 
       12.2. Informative References...............................20 
    Author's Addresses............................................21 
    Copyright Statement...........................................22 
    Acknowledgment................................................22 
    Appendix A - Communication Channel (CCh) Examples.............23 
     





  

 Gray, et al              Expires April, 2010               [Page 2] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

 1. Introduction 

    This document specifies the requirements for the management of 
    equipment used in networks supporting an MPLS Transport Profile 
    (MPLS-TP). The requirements are defined for specification of 
    network management aspects of protocol mechanisms and procedures 
    that constitute the building blocks out of which the MPLS 
    transport profile is constructed.  That is, these requirements 
    indicate what management capabilities need to be available in 
    MPLS for use in managing the MPLS-TP. This document is intended 
    to identify essential network management capabilities, not to 
    specify what functions any particular MPLS implementation 
    supports.   

    This document also leverages management requirements specified in 
    ITU-T G.7710/Y.1701 [1] and RFC 4377 [2], and attempts to comply 
    with best common practice as defined in [15].  

    ITU-T G.7710/Y.1701 defines generic management requirements for 
    transport networks. RFC 4377 specifies the OAM requirements, 
    including OAM-related network management requirements, for MPLS 
    networks.  

    This document is a product of a joint ITU-T and IETF effort to 
    include an MPLS Transport Profile (MPLS-TP) within the IETF MPLS 
    and PWE3 architectures to support capabilities and functionality 
    of a transport network as defined by ITU-T. 

    The requirements in this document derive from two sources: 

       1) MPLS and PWE3 architectures as defined by IETF, and 

       2) packet transport networks as defined by ITU-T. 

    Requirements for management of equipment in MPLS-TP networks are 
    defined herein.  Related functions of MPLS and PWE3 are defined 
    elsewhere (and are out of scope in this document). 

    This document expands on the requirements in [1] and [2] to cover 
    fault, configuration, performance, and security management for 
    MPLS-TP networks, and the requirements for object and information 
    models needed to manage MPLS-TP Networks and Network Elements. 

    In writing this document, the authors assume the reader is 
    familiar with references [8] and [9]. 


  
  
 Gray, et al              Expires April, 2010               [Page 3] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

  1.1. Terminology 

    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 [5]. Although this document is not a protocol 
    specification, the use of this language clarifies the 
    instructions to protocol designers producing solutions that 
    satisfy the requirements set out in this document.   

    Anomaly: The smallest discrepancy which can be observed between 
    actual and desired characteristics of an item. The occurrence of 
    a single anomaly does not constitute an interruption in ability 
    to perform a required function. Anomalies are used as the input 
    for the Performance Monitoring (PM) process and for detection of 
    defects (from [21], 3.7). 

    Communication Channel (CCh): A logical channel between network 
    elements (NEs) that can be used - e.g. - for management or 
    control plane applications. The physical channel supporting the 
    CCh is technology specific.  See Appendix A. 

    Data Communication Network (DCN): A network that supports Layer 1 
    (physical layer), Layer 2 (data-link layer), and Layer 3 (network 
    layer) functionality for distributed management communications 
    related to the management plane, for distributed signaling 
    communications related to the control plane, and other operations 
    communications (e.g., order-wire/voice communications, software 
    downloads, etc.).  

    Defect: The density of anomalies has reached a level where the 
    ability to perform a required function has been interrupted. 
    Defects are used as input for performance monitoring, the control 
    of consequent actions, and the determination of fault cause (from 
    [21], 3.24). 

    Failure: The fault cause persisted long enough to consider the 
    ability of an item to perform a required function to be 
    terminated. The item may be considered as failed; a fault has now 
    been detected (from [21], 3.25).  

    Fault: A fault is the inability of a function to perform a 
    required action. This does not include an inability due to 
    preventive maintenance, lack of external resources, or planned 
    actions (from [21], 3.26). 


  
  
 Gray, et al              Expires April, 2010               [Page 4] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

    Fault Cause: A single disturbance or fault may lead to the 
    detection of multiple defects. A fault cause is the result of a 
    correlation process which is intended to identify the defect that 
    is representative of the disturbance or fault that is causing the 
    problem (from [21], 3.27). 

    Fault Cause Indication (FCI): An indication of a fault cause. 

    Management Communication Channel (MCC): A CCh dedicated for 
    management plane communications.  

    Management Communication Network (MCN): A DCN supporting 
    management plane communication is referred to as a Management 
    Communication Network (MCN).  

    MPLS-TP NE: A network element (NE) that supports the functions of 
    MPLS necessary to participate in an MPLS-TP based transport 
    service. See [7] for further information on functionality 
    required to support MPLS-TP. 

    MPLS-TP network: a network in which MPLS-TP NEs are deployed.  

    OAM, On-Demand and Proactive: One feature of OAM that is largely 
    a management issue is control of OAM; on-demand and proactive are 
    modes of OAM mechanism operation defined - for example - in 
    Y.1731 ([22] - 3.45 and 3.44 respectively) as: 

       . On-demand OAM - OAM actions which are initiated via manual 
          intervention for a limited time to carry out diagnostics. 
          On-demand OAM can result in singular or periodic OAM actions 
          during the diagnostic time interval. 

       . Proactive OAM - OAM actions which are carried on 
          continuously to permit timely reporting of fault and/or 
          performance status. 

    (Note that it is possible for specific OAM mechanisms to only 
    have a sensible use in either on-demand or proactive mode.) 

    Operations System (OS): A system that performs the functions that 
    support processing of information related to operations, 
    administration, maintenance, and provisioning (OAM&P) for the 
    networks, including surveillance and testing functions to support 
    customer access maintenance. 



  
  
 Gray, et al              Expires April, 2010               [Page 5] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

    Signaling Communication Channel (SCC): A CCh dedicated for 
    control plane communications. The SCC can be used for GMPLS/ASON 
    signaling and/or other control plane messages (e.g., routing 
    messages).  

    Signaling Communication Network (SCN): A DCN supporting control 
    plane communication is referred to as a Signaling Communication 
    Network (SCN). 

 2. Management Interface Requirements  

    This document does not specify a preferred management interface 
    protocol to be used as the standard protocol for managing MPLS-TP 
    networks. Managing an end-to-end connection across multiple 
    operator domains where one domain is managed (for example) via 
    NETCONF ([16]) or SNMP ([17]), and another domain via CORBA 
    ([18]), is allowed.  

       1) For the management interface to the management system, an 
         MPLS-TP NE MAY actively support more than one management 
         protocol in any given deployment.  

    For example, an operator can use one protocol for configuration 
    of an MPLS-TP NE and another for monitoring. The protocols to be 
    supported are at the discretion of the operator.  

 3. Management Communication Channel (MCC) Requirements 

       1) Specifications SHOULD define support for management 
         connectivity with remote MPLS-TP domains and NEs, as well as 
         with termination points located in NEs under the control of 
         a third party network operator.  See ITU-T G.8601 [23] for 
         example scenarios in multi-carrier multi-transport-
         technology environments. 

       2) For management purpose, every MPLS-TP NE MUST connect to an 
         OS. The connection MAY be direct (e.g. - via a software, 
         hardware or proprietary protocol connection) or indirect 
         (via another MPLS-TP NE). In this document, any management 
         connection that is not via another MPLS-TP NE is a direct 
         management connection.  When an MPLS-TP NE is connected 
         indirectly to an OS, an MCC MUST be supported between that 
         MPLS-TP NE and any MPLS-TP NE(s) used to provide the 
         connection to an OS.   

     

  
  
 Gray, et al              Expires April, 2010               [Page 6] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

 4. Management Communication Network (MCN) Requirements 

    Entities of the MPLS-TP management plane communicate via a DCN, 
    or more specifically via the MCN. The MCN connects management 
    systems with management systems, management systems with MPLS-TP 
    NEs, and (in the indirect connectivity case discussed in section 
    3) MPLS-TP NEs with MPLS-TP NEs.  

    RFC 5586 [14] defines a Generic Associated Channel (G-ACh) to 
    enable the realization of a communication channel (CCh) between 
    adjacent MPLS-TP NEs for management and control. Reference [10] 
    describes how the G-ACh can be used to provide infrastructure 
    that forms part of the MCN and SCN. It also explains how MCN and 
    SCN messages are encapsulated, carried on the G-ACh, and 
    decapsulated for delivery to management or signaling/routing 
    control plane components on a label switching router (LSR). 

    ITU-T G.7712/Y.1703 [6], section 7, describes the transport DCN 
    architecture and requirements.  

       1) The MPLS-TP MCN MUST support the requirements (in reference 
          [6]) for: 

         a) CCh access functions specified in section 7.1.1; 

         b) MPLS-TP SCC data-link layer termination functions 
            specified in section 7.1.2.3; 

         c) MPLS-TP MCC data-link layer termination functions 
            specified in section 7.1.2.4; 

         d) Network layer PDU into CCh data-link frame encapsulation 
            functions specified in section 7.1.3; 

         e) Network layer PDU forwarding (7.1.6), interworking (7.1.7) 
            and encapsulation (7.1.8) functions, as well as tunneling 
            (7.1.9) and routing (7.1.10) functions specified in [6]. 

    As a practical matter, MCN connections will typically have 
    addresses. See the section on Identifiers in [8] for further
    information. 

    In order to have the MCN operate properly, a number of management 
    functions for the MCN are needed, including: 



  
  
 Gray, et al              Expires April, 2010               [Page 7] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

       . Retrieval of DCN network parameters to ensure compatible 
         functioning, e.g. packet size, timeouts, quality of service, 
         window size, etc.; 

       . Establishment of message routing between DCN nodes;  

       . Management of DCN network addresses; 

       . Retrieval of operational status of the DCN at a given node; 

       . Capability to enable/disable access by an NE to the DCN. 
         Note that this is to allow isolating a malfunctioning NE 
         from impacting the rest of the network. 

 5. Fault Management Requirements 

    The Fault Management functions within an MPLS-TP NE enable the 
    supervision, detection, validation, isolation, correction, and 
    reporting of abnormal operation of the MPLS-TP network and its 
    environment. 

 5.1. Supervision Function 

    The supervision function analyses the actual occurrence of a 
    disturbance or fault for the purpose of providing an appropriate 
    indication of performance and/or detected fault condition to 
    maintenance personnel and operations systems. 

       1) The MPLS-TP NE MUST support supervision of the OAM 
         mechanisms that are deployed for supporting the OAM 
         requirements defined in [3]. 

       2) The MPLS-TP NE MUST support the following data-plane 
         forwarding path supervision functions:  

         a) Supervision of loop-checking functions used to detect 
            loops in the data-plane forwarding path (which result in 
            non-delivery of traffic, wasting of forwarding resources 
            and unintended self-replication of traffic); 

         b) Supervision of failure detection; 

       3) The MPLS-TP NE MUST support the capability to configure 
         data-plane forwarding path related supervision mechanisms to 
         perform on-demand or proactively.  


  
  
 Gray, et al              Expires April, 2010               [Page 8] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

       4) The MPLS-TP NE MUST support supervision for software 
         processing - e.g., processing faults, storage capacity, 
         version mismatch, corrupted data and out of memory problems, 
         etc. 

       5) The MPLS-TP NE MUST support hardware-related supervision for 
         interchangeable and non-interchangeable unit, cable, and 
         power problems.  

       6) The MPLS-TP NE SHOULD support environment-related 
         supervision for temperature, humidity, etc.  

 5.2. Validation Function 

    Validation is the process of integrating Fault Cause indications 
    into Failures. A Fault Cause Indication (FCI) indicates a limited 
    interruption of the required transport function. A Fault Cause is 
    not reported to maintenance personnel because it might exist only 
    for a very short time. Note that some of these events are summed 
    up in the Performance Monitoring process (see section 7), and 
    when this sum exceeds a configured value, a threshold crossing 
    alert (report) can be generated. 

    When the Fault Cause lasts long enough, an inability to perform 
    the required transport function arises. This failure condition is 
    subject to reporting to maintenance personnel and/or an OS 
    because corrective action might be required. Conversely, when the 
    Fault Cause ceases after a certain time, clearing of the Failure 
    condition is also subject to reporting. 

       1) The MPLS-TP NE MUST perform persistency checks on fault 
         causes before it declares a fault cause a failure.  

       2) The MPLS-TP NE SHOULD provide a configuration capability for 
         control parameters associated with performing the 
         persistency checks described above. 

       3) An MPLS-TP NE MAY provide configuration parameters to 
         control reporting, and clearing, of failure conditions. 

       4) A data-plane forwarding path failure MUST be declared if the 
         fault cause persists continuously for a configurable time 
         (Time-D). The failure MUST be cleared if the fault cause is 
         absent continuously for a configurable time (Time-C).   

    Note: As an example, the default time values might be as follows: 

  
  
 Gray, et al              Expires April, 2010               [Page 9] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

       Time-D = 2.5 +/- 0.5 seconds 

       Time-C = 10 +/- 0.5 seconds 

    These time values are as defined in G.7710 [1]. 

       5) MIBs - or other object management semantics specifications - 
         defined to enable configuration of these timers SHOULD 
         explicitly provide default values and MAY provide guidelines 
         on ranges and value determination methods for scenarios 
         where the default value chosen might be inadequate. In 
         addition, such specifications SHOULD define the level of 
         granularity at which tables of these values are to be 
         defined.  

       6) Implementations MUST provide the ability to configure the 
         preceding set of timers, and SHOULD provide default values 
         to enable rapid configuration. Suitable default values, 
         timer ranges, and level of granularity are out of scope in 
         this document and form part of the specification of fault 
         management details. Timers SHOULD be configurable per NE for 
         broad categories (for example, defects and/or fault causes), 
         and MAY be configurable per-interface on an NE and/or per 
         individual defect/fault cause. 

       7) The failure declaration and clearing MUST be time stamped. 
         The time-stamp MUST indicate the time at which the fault 
         cause is activated at the input of the fault cause 
         persistency (i.e. defect-to-failure integration) function, 
         and the time at which the fault cause is deactivated at the 
         input of the fault cause persistency function. 

 5.3. Alarm Handling Function 

 5.3.1. Alarm Severity Assignment 

    Failures can be categorized to indicate the severity or urgency 
    of the fault.  

       1) An MPLS-TP NE SHOULD support the ability to assign severity 
         (e.g., Critical, Major, Minor, Warning) to alarm conditions 
         via configuration. 

    See G.7710 [1], section 7.2.2 for more detail on alarm severity 
    assignment. For additional discussion of Alarm Severity 
    management, see discussion of alarm severity in RFC 3877 [11]. 

  
  
 Gray, et al              Expires April, 2010              [Page 10] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

 5.3.2. Alarm Suppression 

    Alarms can be generated from many sources, including OAM, device 
    status, etc. 

       1) An MPLS-TP NE MUST support suppression of alarms based on 
         configuration.  

 5.3.3. Alarm Reporting 

    Alarm Reporting is concerned with the reporting of relevant 
    events and conditions, which occur in the network (including the 
    NE, incoming signal, and external environment). 

    Local reporting is concerned with automatic alarming by means of 
    audible and visual indicators near the failed equipment.  

       1) An MPLS-TP NE MUST support local reporting of alarms. 

       2) The MPLS-TP NE MUST support reporting of alarms to an OS. 
         These reports are either autonomous reports (notifications) 
         or reports on request by maintenance personnel. The MPLS-TP 
         NE SHOULD report local (environmental) alarms to a network 
         management system. 

       3) An MPLS-TP NE supporting one or more other networking 
         technologies (e.g. - Ethernet, SDH/SONET, MPLS) over MPLS-TP 
         MUST be capable of translating an MPLS-TP defects into 
         failure conditions that are meaningful to the client layer, 
         as described in RFC 4377 [2], section 4.7. 

 5.3.4. Alarm Reporting Control 

    Alarm Reporting Control (ARC) supports an automatic in-service 
    provisioning capability. Alarm reporting can be turned off on a 
    per-managed entity (e.g., LSP) basis to allow sufficient time for 
    customer service testing and other maintenance activities in an 
    "alarm free" state. Once a managed entity is ready, alarm 
    reporting is automatically turned on. 

       1) An MPLS-TP NE SHOULD support the Alarm Reporting Control 
         function for controlling the reporting of alarm conditions. 

    See G.7710 [1] (section 7.1.3.2) and RFC 3878 [24] for more 
    information about ARC.    


  
  
 Gray, et al              Expires April, 2010              [Page 11] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

 6. Configuration Management Requirements 

    Configuration Management provides functions to identify, collect 
    data from, provide data to and control NEs.  Specific 
    configuration tasks requiring network management support include 
    hardware and software configuration, configuration of NEs to 
    support transport paths (including required working and 
    protection paths), and configuration of required path 
    integrity/connectivity and performance monitoring (i.e. - OAM). 

 6.1. System Configuration 

       1) The MPLS-TP NE MUST support the configuration requirements 
         specified in G.7710 [1] section 8.1 for hardware.  

       2) The MPLS-TP NE MUST support the configuration requirements 
         specified in G.7710 [1] section 8.2 for software.  

       3) The MPLS-TP NE MUST support the configuration requirements 
         specified in G.7710 [1] section 8.13.2.1 for local real time 
         clock functions. 

       4) The MPLS-TP NE MUST support the configuration requirements 
         specified in G.7710 [1] section 8.13.2.2 for local real time 
         clock alignment with external time reference. 

       5) The MPLS-TP NE MUST support the configuration requirements 
         specified in G.7710 [1] section 8.13.2.3 for performance 
         monitoring of the clock function. 

 6.2. Control Plane Configuration 

       1) If a control plane is supported in an implementation of 
         MPLS-TP, the MPLS-TP NE MUST support the configuration of 
         MPLS-TP control plane functions by the management plane. 
         Further detailed requirements will be provided along with 
         progress in defining the MPLS-TP control plane in 
         appropriate specifications. 

 6.3. Path Configuration 

       1) In addition to the requirement to support static 
         provisioning of transport paths (defined in [7], section 2.1 
         - General Requirements - requirement 18), an MPLS-TP NE MUST 
         support the configuration of required path performance 
         characteristic thresholds (e.g. - Loss Measurement <LM>, 

  
  
 Gray, et al              Expires April, 2010              [Page 12] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

         Delay Measurement <DM> thresholds) necessary to support 
         performance monitoring of the MPLS-TP service(s). 

       2) In order to accomplish this, an MPLS-TP NE MUST support 
         configuration of LSP information (such as an LSP identifier 
         of some kind) and/or any other information needed to 
         retrieve LSP status information, performance attributes, 
         etc. 

       3) If a control plane is supported, and that control plane 
         includes support for control-plane/management-plane hand-off 
         for LSP setup/maintenance, the MPLS-TP NE MUST support 
         management of the hand-off of Path control. See, for 
         example, references [19] and [20]. 

       4) Further detailed requirements SHALL be provided along with 
         progress in defining the MPLS-TP control plane in 
         appropriate specifications. 

       5) If MPLS-TP transport paths cannot be statically provisioned 
         using MPLS LSP and pseudo-wire management tools (either 
         already defined in standards or under development), further 
         management specifications MUST be provided as needed. 

 6.4. Protection Configuration 

       1) The MPLS-TP NE MUST support configuration of required path 
         protection information as follows: 

       . designate specifically identified LSPs as working or 
          protecting LSPs; 

       . define associations of working and protecting paths; 

       . operate/release manual protection switching; 

       . operate/release force protection switching; 

       . operate/release protection lockout; 

       . set/retrieve Automatic Protection Switching (APS) 
          parameters, including -  

         o  Wait to Restore time, 

         o  Protection Switching threshold information. 

  
  
 Gray, et al              Expires April, 2010              [Page 13] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

          
 6.5. OAM Configuration 

       1) The MPLS-TP NE MUST support configuration of the OAM 
         entities and functions specified in [3].

       2) The MPLS-TP NE MUST support the capability to choose which 
         OAM functions are enabled. 

       3) For enabled OAM functions, the MPLS-TP NE MUST support the 
         ability to associate OAM functions with specific maintenance 
         entities.   

       4) The MPLS-TP NE MUST support the capability to configure the 
         OAM entities/functions as part of LSP setup and tear-down, 
         including co-routed bidirectional point-to-point, associated 
         bidirectional point-to-point, and uni-directional (both 
         point-to-point and point-to-multipoint) connections.  

       5) The MPLS-TP NE MUST support the configuration of maintenance 
         entity identifiers (e.g. MEP ID and MIP ID) for the purpose 
         of LSP connectivity checking.  

       6) The MPLS-TP NE MUST support configuration of OAM parameters 
         to meet their specific operational requirements, such as 
         whether - 

         a) one-time on-demand immediately or  

         b) one-time on-demand pre-scheduled or  

         c) on-demand periodically based on a specified schedule or 

         d) proactive on-going.  

       7) The MPLS-TP NE MUST support the enabling/disabling of the 
         connectivity check processing. The connectivity check 
         process of the MPLS-TP NE MUST support provisioning of the 
         identifiers to be transmitted and the expected identifiers. 

 7. Performance Management Requirements 

    Performance Management provides functions for the purpose of 
    Maintenance, Bring-into-service, Quality of service, and 
    statistics gathering.  


  
  
 Gray, et al              Expires April, 2010              [Page 14] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

    This information could be used, for example, to compare behavior 
    of the equipment, MPLS-TP NE or network at different moments in 
    time to evaluate changes in network performance. 

    ITU-T Recommendation G.7710 [1] provides transport performance 
    monitoring requirements for packet-switched and circuit-switched 
    transport networks with the objective of providing coherent and 
    consistent interpretation of the network behavior in a multi-
    technology environment. The performance management requirements 
    specified in this document are driven by such an objective. 

 7.1. Path Characterization Performance Metrics 

       1) It MUST be possible to determine when an MPLS-TP based 
         transport service is available and when it is unavailable.   

    From a performance perspective, a service is unavailable if there 
    is an indication that performance has degraded to the extent that 
    a configurable performance threshold has been crossed and the 
    degradation persists long enough (i.e. - the indication persists 
    for some amount of time - which is either configurable, or well-
    known) to be certain it is not a measurement anomaly. 

    Methods, mechanisms and algorithms for exactly how unavailability 
    is to be determined - based on collection of raw performance data 
    - are out of scope for this document.  

       2) The MPLS-TP NE MUST support collection and reporting of raw 
         performance data that MAY be used in determining the 
         unavailability of a transport service. 

       3) MPLS-TP MUST support the determination of the unavailability 
         of the transport service. The result of this determination 
         MUST be available via the MPLS-TP NE (at service termination 
         points), and determination of unavailability MAY be 
         supported by the MPLS-TP NE directly. To support this 
         requirement, the MPLS-TP NE management information model 
         MUST include objects corresponding to availability-state of 
         services. 

    Transport network unavailability is based on Severely Errored 
    Seconds (SES) and Unavailable Seconds (UAS). ITU-T is 
    establishing definitions of unavailability generically applicable 
    to packet transport technologies, including MPLS-TP, based on SES 
    and UAS. Note that SES and UAS are already defined for Ethernet 
    transport networks in ITU-T Recommendation Y.1563 [25]. 

  
  
 Gray, et al              Expires April, 2010              [Page 15] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

       4) The MPLS-TP NE MUST support collection of loss measurement 
         (LM) statistics. 

       5) The MPLS-TP NE MUST support collection of delay measurement 
         (DM) statistics. 

       6) The MPLS-TP NE MUST support reporting of Performance 
         degradation via fault management for corrective actions.  

    "Reporting" in this context could mean: 

          . reporting to an autonomous protection component to 
            trigger protection switching, 

          . reporting via a craft interface to allow replacement of a 
            faulty component (or similar manual intervention), 

          . etc. 

       7) The MPLS-TP NE MUST support reporting of performance 
         statistics on request from a management system. 

 7.2. Performance Measurement Instrumentation 

 7.2.1. Measurement Frequency 

       1) For performance measurement mechanisms that support both 
         proactive and on-demand modes, the MPLS-TP NE MUST support 
         the capability to be configured to operate on-demand or 
         proactively.  

 7.2.2. Measurement Scope 

    On measurement of packet loss and loss ratio: 

       1) For bidirectional (both co-routed and associated) P2P 
          connections -  

          a) on-demand measurement of single-ended packet loss, and 
            loss ratio, measurement is REQUIRED; 

          b) proactive measurement of packet loss, and loss ratio, 
            measurement for each direction is REQUIRED. 

       2) For unidirectional (P2P and P2MP) connection, proactive 
          measurement of packet loss, and loss ratio, is REQUIRED. 

  
  
 Gray, et al              Expires April, 2010              [Page 16] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

    On Delay measurement:  

       3) For unidirectional (P2P and P2MP) connection, on-demand 
       measurement of delay measurement is REQUIRED. 

       4) For co-routed bidirectional (P2P) connection, on-demand 
       measurement of one-way and two-way delay is REQUIRED. 

       5) For associated bidirectional (P2P) connection, on-demand 
       measurement of one-way delay is REQUIRED. 

 8. Security Management Requirements 

       1) The MPLS-TP NE MUST support secure management and control 
          planes. 

 8.1. Management Communication Channel Security 

       1) Secure communication channels MUST be supported for all 
         network traffic and protocols used to support management 
         functions.  This MUST include, at least, protocols used for 
         configuration, monitoring, configuration backup, logging, 
         time synchronization, authentication, and routing.   

       2) The MCC MUST support application protocols that provide 
         confidentiality and data integrity protection.   

       3) The MPLS-TP NE MUST support the following: 

         a) Use of open cryptographic algorithms (See RFC 3871 [4]) 

         b) Authentication - allow management connectivity only from 
            authenticated entities.  

         c) Authorization - allow management activity originated by an 
            authorized entity, using (for example) an Access Control 
            List (ACL). 

         d) Port Access Control - allow management activity received 
            on an authorized (management) port. 

 8.2. Signaling Communication Channel Security 

    Security requirements for the SCC are driven by considerations 
    similar to MCC requirements described in section 8.1.  


  
  
 Gray, et al              Expires April, 2010              [Page 17] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

    Security Requirements for the control plane are out of scope for 
    this document and are expected to be defined in the appropriate 
    control plane specifications.  

       1) Management of control plane security MUST be defined in the 
         appropriate control plane specifications.. 

 8.3. Distributed Denial of Service 

    A Denial of Service (DoS) attack is an attack that tries to 
    prevent a target from performing an assigned task, or providing 
    its intended service(s), through any means. A Distributed DoS 
    (DDoS) can multiply attack severity (possibly by an arbitrary 
    amount) by using multiple (potentially compromised) systems to 
    act as topologically (and potentially geographically) distributed 
    attack sources. It is possible to lessen the impact and potential 
    for DoS and DDoS by using secure protocols, turning off 
    unnecessary processes, logging and monitoring, and ingress 
    filtering.  RFC 4732 [26] provides background on DoS in the 
    context of the Internet. 

       1) An MPLS-TP NE MUST support secure management protocols and 
         SHOULD do so in a manner that reduces potential impact of a 
         DoS attack. 

       2) An MPLS-TP NE SHOULD support additional mechanisms that 
         mitigate a DoS (or DDoS) attack against the management 
         component while allowing the NE to continue to meet its 
         primary functions. 

 9. Security Considerations 

    Section 8 includes a set of security requirements that apply to 
    MPLS-TP network management. 

       1) Solutions MUST provide mechanisms to prevent unauthorized 
         and/or unauthenticated access to management capabilities and 
         private information by network elements, systems or users. 

    Performance of diagnostic functions and path characterization 
    involves extracting a significant amount of information about 
    network construction that the network operator might consider 
    private. 




  
  
 Gray, et al              Expires April, 2010              [Page 18] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

 10. IANA Considerations 

    There are no IANA actions associated with this document. 

 11. Acknowledgments 

    The authors/editors gratefully acknowledge the thoughtful review, 
    comments and explanations provided by Adrian Farrel, Alexander 
    Vainshtein, Andrea Maria Mazzini, Ben Niven-Jenkins, Bernd 
    Zeuner, Dan Romascanu, Daniele Ceccarelli, Diego Caviglia, Dieter 
    Beller, He Jia, Leo Xiao, Maarten Vissers, Neil Harrison, Rolf 
    Winter, Yoav Cohen and Yu Liang. 

 12. References  

 12.1. Normative References 

    [1]   ITU-T Recommendation G.7710/Y.1701, "Common equipment 
          management function requirements", July, 2007. 

    [2]   Nadeau, T., et al, "Operations and Management (OAM) 
          Requirements for Multi-Protocol Label Switched (MPLS) 
          Networks", RFC 4377, February 2006. 

    [3]   Vigoureux, M., et al, "Requirements for OAM in MPLS 
          Transport Networks", draft-ietf-mpls-tp-oam-requirements,
          work in progress. 

    [4]   Jones, G., "Operational Security Requirements for Large 
          Internet Service Provider (ISP) IP Network Infrastructure", 
          RFC 3871, September 2004. 

    [5]   Bradner, S., "Key words for use in RFCs to Indicate 
          Requirement Levels", RFC 2119, March 1997. 

    [6]   ITU-T Recommendation G.7712/Y.1703, "Architecture and 
          specification of data communication network", June 2008. 

    [7]   Niven-Jenkins, B. et al, "MPLS-TP Requirements", draft-
          ietf-mpls-tp-requirements, work in progress.  

    [8]   Bocci, M. et al, "A Framework for MPLS in Transport 
          Networks", draft-ietf-mpls-tp-framework, work in progress.  

    [9]   Mansfield, S. et al, "MPLS-TP Network Management 
          Framework", draft-ietf-mpls-tp-nm-framework, work in 
          progress. 
  
  
 Gray, et al              Expires April, 2010              [Page 19] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

 12.2. Informative References 

    [10]  Beller, D., et al, "An Inband Data Communication Network 
          For the MPLS Transport Profile", draft-ietf-mpls-tp-gach-
          dcn, work in progress.  

    [11]  Chisholm, S. and D. Romascanu, "Alarm Management 
          Information Base (MIB)", RFC 3877, September 2004. 

    [12]  ITU-T Recommendation M.20, "Maintenance philosophy for 
          telecommunication networks", October 1992. 

    [13]  Telcordia, "Network Maintenance: Network Element and 
          Transport Surveillance Messages" (GR-833-CORE), Issue 5, 
          August 2004. 

    [14]  Bocci, M. et al, "MPLS Generic Associated Channel", RFC 
          5586, June 2009. 

    [15]  Harrington, D., "Guidelines for Considering Operations and 
          Management of New Protocols and Protocol Extensions", 
          draft-ietf-opsawg-operations-and-management, work in 
          progress. 

    [16]  Enns, R. et al, "NETCONF Configuration Protocol", draft-
          ietf-netconf-4741bis, work in progress. 

    [17]  Presuhn, R. et al, "Version 2 of the Protocol Operations 
          for the Simple Network Management Protocol (SNMP)", RFC 
          3416, December 2002. 

    [18]  OMG Document formal/04-03-12, "The Common Object Request 
          Broker: Architecture and Specification", Revision 3.0.3. 
          March 12, 2004. 

    [19]  Caviglia, D. et al, "Requirements for the Conversion 
          between Permanent Connections and Switched Connections in a 
          Generalized Multiprotocol Label Switching (GMPLS) Network", 
          RFC 5493, April 2009. 

    [20]  Caviglia, D. et al, "RSVP-TE Signaling Extension For The 
          Conversion Between Permanent Connections And Soft Permanent 
          Connections In A GMPLS Enabled Transport Network", draft-
          ietf-ccamp-pc-spc-rsvpte-ext, work in progress. 



  
  
 Gray, et al              Expires April, 2010              [Page 20] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

    [21]  ITU-T Recommendation G.806, "Characteristics of transport 
          equipment - Description methodology and generic 
          functionality", January, 2009. 

    [22]  ITU-T Recommendation Y.1731, "OAM functions and mechanisms 
          for Ethernet based networks", February, 2008.  

    [23]  ITU-T Recommendation G.8601, "Architecture of service 
          management in multi bearer, multi carrier environment", 
          June 2006. 

    [24]  Lam, H., et al, "Alarm Reporting Control Management 
          Information Base (MIB)", RFC 3878, September 2004. 

    [25]  ITU-T Recommendation Y.1563, "Ethernet frame transfer and 
          availability performance", January 2009.  

    [26]  Handley, M., et al, "Internet Denial-of-Service 
          Considerations", RFC 4732, November 2006. 

  Authors' Addresses  

     
    Eric Gray 
    Ericsson 
    900 Chelmsford Street 
    Lowell, MA, 01851 
    Phone: +1 978 275 7470 
    Email: Eric.Gray@Ericsson.com 

    Scott Mansfield 
    Ericsson 
    250 Holger Way 
    San Jose CA, 95134 
    +1 724 931 9316 
    EMail: Scott.Mansfield@Ericsson.com 
     
    Hing-Kam (Kam) Lam 
    Alcatel-Lucent 
    600-700 Mountain Ave 
    Murray Hill, NJ, 07974 
    Phone: +1 908 582 0672 
    Email: hklam@Alcatel-Lucent.com  
     



  
  
 Gray, et al              Expires April, 2010              [Page 21] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

 Contributor's Address 

     
    Adrian Farrel 
    Old Dog Consulting 
    Email: adrian@olddog.co.uk 
     
 Copyright Statement 

    Copyright (c) 2009 IETF Trust and the persons identified as the 
    document authors.  All rights reserved. 

    This document is subject to BCP 78 and the IETF Trust's Legal 
    Provisions Relating to IETF Documents in effect on the date of 
    publication of this document (http://trustee.ietf.org/license-
    info).  Please review these documents carefully, as they describe 
    your rights and restrictions with respect to this document. 

 Acknowledgment 

    Funding for the RFC Editor function is currently provided by the 
    Internet Society. 

























  
  
 Gray, et al              Expires April, 2010              [Page 22] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

 Appendix A- Communication Channel (CCh) Examples 

    A CCh can be realized in a number of ways. 

    1. The CCh can be provided by a link in a physically distinct 
    network.  That is, a link that is not part of the transport 
    network that is being managed. For example, the nodes in the 
    transport network can be interconnected in two distinct physical 
    networks: the transport network and the DCN. 

    This is a "physically distinct out-of-band CCh". 

    2. The CCh can be provided by a link in the transport network 
    that is terminated at the ends of the DCC and which is capable of 
    encapsulating and terminating packets of the management 
    protocols.  For example, in MPLS-TP a single-hop LSP might be 
    established between two adjacent nodes, and that LSP might be 
    capable of carrying IP traffic. Management traffic can then be 
    inserted into the link in an LSP parallel to the LSPs that carry 
    user traffic. 

    This is a "physically shared out-of-band CCh." 

    3. The CCh can be supported as its native protocol on the 
    interface alongside the transported traffic. For example, if an 
    interface is capable of sending and receiving both MPLS-TP and 
    IP, the IP-based management traffic can be sent as native IP 
    packets on the interface. 

    This is a "shared interface out-of-band CCh". 

    4. The CCh can use overhead bytes available on a transport 
    connection. For example, in TDM networks there are overhead bytes 
    associated with a data channel, and these can be used to provide 
    a CCh. It is important to note that the use of overhead bytes 
    does not reduce the capacity of the associated data channel. 

    This is an "overhead-based CCh". 

    This alternative is not available in MPLS-TP because there is no 
    overhead available. 

    5. The CCh can provided by a dedicated channel associated with 
    the data link. For example, the generic associated label (GAL) 
    [14] can be used to label DCC traffic being exchanged on a data 


  
  
 Gray, et al              Expires April, 2010              [Page 23] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

    link between adjacent transport nodes, potentially in the absence 
    of any data LSP between those nodes. 

    This is a "data link associated CCh". 

    It is very similar to case 2, and by its nature can only span a 
    single hop in the transport network. 

    6. The CCh can be provided by a dedicated channel associated with 
    a data channel. For example, in MPLS-TP the GAL [14] can be 
    imposed under the top label in the label stack for an MPLS-TP LSP 
    to create a channel associated with the LSP that can carry 
    management traffic. This CCh requires the receiver to be capable 
    of demultiplexing management traffic from user traffic carried on 
    the same LSP by use of the GAL. 

    This is a "data channel associated CCh". 

    7. The CCh can be provided by mixing the management traffic with 
    the user traffic such that is indistinguishable on the link 
    without deep-packet inspection. In MPLS-TP this could arise if 
    there is a data-carrying LSP between two nodes, and management 
    traffic is inserted into that LSP. This approach requires that 
    the termination point of the LSP is able to demultiplex the 
    management and user traffic. Such might be possible in MPLS-TP if 
    the MPLS-TP LSP was carrying IP user traffic. 

    This is an "in-band CCh". 

    These realizations can be categorized as: 

       A. Out-of-fiber, out-of-band (types 1 and 2) 
       B. In-fiber, out-of-band (types 2, 3, 4, and 5) 
       C. In-band (types 6 and 7) 

    The MCN and SCN are logically separate networks and can be 
    realized by the same DCN or as separate networks. In practice, 
    that means that, between any pair of nodes, the MCC and SCC can 
    be the same link or separate links. 

    It is also important to note that the MCN and SCN do not need to 
    be categorised as in-band, out-of-band, etc. This definition only 
    applies to the individual links, and it is possible for some 
    nodes to be connected in the MCN or SCN by one type of link, and 
    other nodes by other types of link. Furthermore, a pair of 

  
  

 Gray, et al              Expires April, 2010              [Page 24] 
  




 Internet-Draft         MPLS-TP NM Requirements        October, 2009 
     

    adjacent nodes can be connected by multiple links of different 
    types. 

    Lastly note that the division of DCN traffic between links 
    between a pair of adjacent nodes is purely an implementation 
    choice. Parallel links can be deployed for DCN resilience or load 
    sharing. Links can be designated for specific use. For example, 
    so that some links carry management traffic and some carry 
    control plane traffic, or so that some links carry signaling 
    protocol traffic while others carry routing protocol traffic. 

    It is important to note that the DCN can be a routed network with 
    forwarding capabilities, but that this is not a requirement. The 
    ability to support forwarding of management or control traffic 
    within the DCN can substantially simplify the topology of the DCN 
    and improve its resilience, but does increase the complexity of 
    operating the DCN. 

    See also RFC 3877 [11], ITU-T M.20 [12], and Telcordia document 
    GR-833-CORE [13] for further information. 

     

























  
  
 Gray, et al              Expires April, 2010              [Page 25] 
  
