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Versions: (draft-gray-mpls-tp-nm-req) 00 01 02 03 04 05 06 RFC 5951

Network Working Group                                  Hing-Kam Lam
Internet Draft                                       Alcatel-Lucent
Expires: March 18, 2010                             Scott Mansfield
Intended Status: Standards Track                          Eric Gray
                                                           Ericsson
                                                 September 18, 2009

               MPLS TP Network Management Requirements
                   draft-ietf-mpls-tp-nm-req-05.txt


Status of this Memo

   This Internet-Draft is submitted to IETF in full conformance
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   This Internet-Draft will expire on March 14, 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.



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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.......6
   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 .............................10
         5.3.3. Alarm Reporting................................11
         5.3.4. Alarm Reporting Control........................11
   6. Configuration Management Requirements....................11
      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...................................13
   7. Performance Management Requirements......................14
      7.1. Path Characterization Performance Metrics...........14
      7.2. Performance Measurement Instrumentation.............16
         7.2.1. Measurement Frequency..........................16
         7.2.2. Measurement Scope .............................16
   8. Security Management Requirements.........................16
      8.1. Management Communication Channel Security...........17
      8.2. Signaling Communication Channel Security............17
      8.3. Distributed Denial of Service ......................17
   9. Security Considerations..................................18
   10. IANA Considerations.....................................18
   11. Acknowledgments.........................................18
   12. References..............................................18
      12.1. Normative References...............................18
      12.2. Informative References.............................19
   Author's Addresses..........................................21
   Copyright Statement.........................................21
   Acknowledgment..............................................22
   Appendix A - Communication Channel (CCh) Examples...........23









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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 [14].

   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 [12] and [15].




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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).






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   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.

   Signaling Communication Channel (SCC): A CCh dedicated for
   control plane communications. The SCC may be used for GMPLS/ASON



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   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 which management interface
   protocol should 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/XML ([16]) or SNMP/SMI ([17]), and another
   domain via CORBA/IDL ([18]), is allowed.

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

3. Management Communication Channel (MCC) Requirements

   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.

   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.

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.




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   RFC 5586 [13] 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 [8]
   describes how the G-ACh may 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. The MPLS-TP MCN MUST support the
   requirements (in reference [6]) for:

     - CCh access functions specified in section 7.1.1;

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

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

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

     - 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 addressing in [15] for further
   information.

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

     . 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;





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     . 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.

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

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

     . 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);

     . Supervision of failure detection;

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

   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.

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

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




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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.

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

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

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

   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:

      Time-D = 2.5 +/- 0.5 seconds

      Time-C = 10 +/- 0.5 seconds

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

   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



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   specifications SHOULD define the level of granularity at which
   tables of these values are to be defined.

   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.

   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.

   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.

5.3.2. Alarm Suppression

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

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










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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.

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

   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.

   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.

   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.

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).



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6.1. System Configuration

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

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

   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.

   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.

   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

   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

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

   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.

   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




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   hand-off of Path control. See, for example, references [19] and
   [20].

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

   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

   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.

6.5. OAM Configuration

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

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

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




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   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.

   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.

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

      1) one-time on-demand immediately or

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

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

      4) proactive on-going.

   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.

   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

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



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   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.

   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.

   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].

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

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

   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),



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      . etc.

   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

   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:

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

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

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

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

   On Delay measurement:

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

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

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

8. Security Management Requirements

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






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8.1. Management Communication Channel Security

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

   The MPLS-TP NE MUST support the following:

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

     - Authentication - allow management connectivity only from
       authenticated entities.

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

     - 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.

   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.

   Management of control plane security MUST also be defined at
   that time.

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



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   ingress filtering.  RFC 4732 [26] provides background on DOS in
   the context of the Internet.

   An MPLS-TP NE MUST support secure management protocols and
   SHOULD do so in a manner the reduce potential impact of a DoS
   attack.

   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.

   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.

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.






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   [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.

12.2. Informative References

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

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

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

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

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

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

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



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   [15]  Mansfield, S. et al, "MPLS-TP Network Management
         Framework", draft-ietf-mpls-tp-nm-framework, work in
         progress.

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

   [17]  McCloghrie, K. et al, "Structure of Management Information
         Version 2 (SMIv2)", RFC 2578, April 1999.

   [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.

   [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.






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Editors' 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

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.










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Acknowledgment

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














































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Appendix A- Communication Channel (CCh) Examples

   A CCh may be realized in a number of ways.

   1. The CCh may 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 may 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 may be provided by a link in the transport network
      that is terminated at the ends of the CCh 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 may 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 may 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 may provided by a dedicated channel associated with
      the data link. For example, the generic associated label (GAL)
      [13] may be used to label CCh traffic being exchanged on a data




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      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 may be provided by a dedicated channel associated
      with a data channel. For example, in MPLS-TP the GAL [13] may be
      imposed under the top label in the label stack for an MPLS-TP
      LSP to create a channel associated with the LSP that may 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 may 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 may 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 may be
   realized by the same DCN or as separate networks. In practice,
   that means that, between any pair of nodes, the MCC and SCC may
   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





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   pair of adjacent nodes may 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 may be deployed for DCN resilience or
   load sharing. Links may 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 should be noted that the DCN may 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 may substantially simplify the topology of the
   DCN and improve its resilience, but does increase the complexity
   of operating the DCN.

   See also RFC 3877 [9], ITU-T M.20 [10], and Telcordia document
   GR-833-CORE [11] for further information.





























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