Network Working Group                                  Hing-Kam Lam
     Internet Draft                                       Alcatel-Lucent
     Expires: March, 2010                                Scott Mansfield
     Intended Status: Standards Track                          Eric Gray
                                                                Ericsson
                                                         August 31, 2009
     
                    MPLS TP Network Management Requirements
                        draft-ietf-mpls-tp-nm-req-03.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 31, 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............................10
              5.3.4. Alarm Reporting Control.....................11
        6. Configuration Management Requirements..................11
           6.1. System Configuration............................11
           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..........16
           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
     
        Although this document is not a protocol specification, 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]
        and are to be interpreted as 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 [8] 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
     
     
     
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        NEs, and (in the indirect connectivity case discussed in section
        3) MPLS-TP NEs with MPLS-TP NEs.
     
        RFC 5586 (Error! Reference source not found.) 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 [7] 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;
     
     
     
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          . 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.
     
        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.
     
     
     
     
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        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.
     
        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
     
     
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        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.
     
        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 [8], 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", 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]   Beller, D., et al, "An Inband Data Communication Network
              For the MPLS Transport Profile", draft-ietf-mpls-tp-gach-
              dcn, work in progress.
     
        [8]   Niven-Jenkins, B. et al, "MPLS-TP Requirements", draft-
              ietf-mpls-tp-requirements, work in progress.
     
     12.2. Informative References
     
        [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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      Author's Addresses
     
        Editors:
     
        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
     
        Author(s):
     
        Contributor(s):
     
        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 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 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 DCC 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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