Network Working Group                                           A.Farrel
Internet-Draft                                                   D. King
Intended status: Informational                        Old Dog Consulting
Expires: March 21, 2011                                     M.Venkatesan
                                                                 Aricent
                                                                 J. Ryoo
                                                                    ETRI
                                                            S. Mansfield
                                                                Ericsson
                                                              K. Koushik
                                                     Cisco Systems, Inc.
                                                      September 21, 2010


        Multiprotocol Label Switching Transport Profile (MPLS-TP)
                       MIB-based Management Overview
           draft-farrel-mpls-tp-mib-management-overview-02.txt

Abstract

   A range of Management Information Base (MIB) modules has been
   developed to help model and manage the various aspects of
   Multiprotocol Label Switching (MPLS) networks.  These MIB modules are
   defined in separate documents that focus on the specific areas of
   responsibility of the modules that they describe.

   The MPLS Transport Profile (MPLS-TP) is a profile of MPLS
   functionality specific to the construction of packet-switched
   transport networks.

   This document describes the MIB-based management architecture for
   MPLS-TP and indicates the interrelationships between the different
   MIB modules used for MPLS-TP network management.

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

   This Informational Internet-Draft is aimed at achieving IETF
   Consensus before publication as an RFC and will be subject to an IETF
   Last Call.

   [RFC Editor, please remove this note before publication as an RFC and
   insert the correct Streams Boilerplate to indicate that the published
   RFC has IETF Consensus.]




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Status of this Memo

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

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

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

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

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

   This Internet-Draft will expire on March 21, 2011.

Copyright Notice

   Copyright (c) 2010 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
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document. Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document. Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.


Table of Contents

   1. Introduction.................................................3
   2. Terminology..................................................4
   3. The SNMP Management Framework................................4
   4. Summary of MPLS-TP Management Function.......................4
   5. Overview of Existing Work....................................4
      5.1. MPLS Management Overview and Requirements...............5
      5.2. An Introduction to the MPLS and Pseudowire MIB Modules..5
           5.2.1. Structure of the MPLS MIB OID Tree...............5
           5.2.2. Textual Convention Modules.......................6

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           5.2.3. Mapping Data to LSPs.............................7
           5.2.4. Label Switching Router Modules...................8
           5.2.5. Label Switched Path Modules......................8
           5.2.6. Pseudowire Modules...............................8
           5.2.7. Routing and Traffic Engineering..................10
           5.2.8. Resiliency.......................................10
           5.2.9. Fault Management and Performance Management......10
           5.2.10. MIB Module Interdependencies....................11
           5.2.11. Dependencies on External MIB Modules............12
   6. Applicability of MPLS MIB modules to MPLS-TP.................13
      6.1  Gap Analysis............................................13
           6.1.1 MPLS-TP Tunnel....................................13
           6.1.2 MPLS-TP Pseudowire................................13
           6.1.3 MPLS-TP Sections..................................13
           6.1.4 MPLS-TP OAM.......................................13
           6.1.5 MPLS-TP Protection Switching......................14
           6.1.6 MIB Module Interdependencies......................15
   7. Interfaces...................................................17
      7.1. MPLS Tunnels as Interfaces..............................17
      7.2. Application of the Interfaces Group to TE Links.........17
      7.3. References to Interface Objects from MPLS MIB Modules...17
   8. Management Options...........................................18
   9. Security Considerations......................................18
   10. IANA Considerations.........................................18
   11. Acknowledgements............................................18
   12. Normative References........................................19
   13. Informational References....................................19
   14. Authors' Addresses..........................................20

1. Introduction

   The MPLS Transport Profile (MPLS-TP) is a packet transport
   technology based on a profile of the MPLS functionality specific
   to the construction of packet-switched transport networks.
   MPLS is described in [RFC3031] and requirements for MPLS-TP are
   specified in [RFC5654].

   A range of Management Information Base (MIB) modules has been
   developed to help model and manage the various aspects of
   Multiprotocol Label Switching (MPLS) networks. These MIB modules
   are defined in separate documents that focus on the specific areas of
   responsibility of the modules that they describe.

   An MPLS-TP network can be operated via static provisioning of
   transport paths, or the elective use of a Generalized MPLS (GMPLS)
   control plane to support dynamic provisioning of transport paths.

   This document describes the MIB-based management architecture for
   MPLS-TP and indicates the interrelationships between the existing
   MIB modules used for MPLS-TP network management. The document also
   indentifies areas where additional MIB modules would be required to
   support an MPLS-TP network.

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


2. Terminology

   This document also uses terminology from the MPLS architecture
   document [RFC3031] and the following MPLS related MIB modules:
   MPLS TC MIB [RFC3811], MPLS LSR MIB [RFC3813], MPLS TE MIB [RFC3812],
   MPLS LDP MIB [RFC3815], MPLS FTN MIB [RFC3814] and TE LINK MIB
   [RFC4220].


3. The SNMP Management Framework

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  MIB objects are generally
   accessed through the Simple Network Management Protocol (SNMP).
   Objects in the MIB are defined using the mechanisms defined in the
   Structure of Management Information (SMI).

   For a detailed overview of the documents that describe the current
   Internet-Standard Management Framework, please refer to section 7 of
   RFC 3410 [RFC3410].

   This document discusses MIB modules that are compliant to the SMIv2,
   which is described in [RFC2578], [RFC2579] and [RFC2580].


4. Summary of MPLS-TP Management Function

   The management of the MPLS-TP networks is separable from that of its
   client networks so that the same means of management can be used
   regardless of the client. The management functions of MPLS-TP
   includes fault management, configuration management, performance
   monitoring, and security management.


5. Overview of Existing Work

   This section describes the existing tools and techniques for
   managing and modeling MPLS networks, devices, and protocols. It does
   not focus on MPLS-TP, but is intended to provide a description of the
   tool kit that is already available.


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   The following section (Section 6. Applicability of MPLS MIB modules
   to MPLS-TP) of this document describes the applicability of the MPLS
   and optional use of GMPLS MIB modules to MPLS-TP and examines the
   additional MIB modules and objects that would be required for
   managing an MPLS-TP network.

5.1. MPLS Management Overview and Requirements

   [RFC4378] outlines how data plane protocols can assist in providing
   the Operations and Management (OAM) requirements outlined in
   [RFC4377] and how it is applied to the management functions of fault,
   configuration, accounting, performance, and security (commonly known
   as FCAPS) for MPLS networks.

   [RFC4221] describes the management architecture for MPLS. In
   particular, it describes how the managed objects defined in various
   MPLS-related MIB modules model different aspects of MPLS, as well as
   the interactions and dependencies between each of these MIB modules.

   [RFC4377] describes the requirements for user and data plane OAM and
   applications for MPLS.

   [RFC5654] describes the requirements for the optional use of a
   control plane to support dynamic provisioning of MPLS-TP transport
   paths. The MPLS-TP LSP control plane is based on GMPLS and is
   described in [RFC3945].

5.2. An Introduction to the MPLS and Pseudowire MIB Modules

5.2.1. Structure of the MPLS MIB OID Tree

   The MPLS MIB OID tree has the following structure compatible for
   MPLS-TP.


















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    mib-2 -- RFC 2578 [RFC2578]
     |
     +-transmission
     |  |
     |  +- mplsStdMIB
     |  |    |
     |  |    +- mplsTCStdMIB -- MPLS-TC-STD-MIB [RFC3811]
     |  |    |
     |  |    +- mplsLsrStdMIB -- MPLS-LSR-STD-MIB [RFC3813]
     |  |    |
     |  |    +- mplsTeStdMIB -- MPLS-TE-STD-MIB [RFC3812]
     |  |    |
     |  |    +- mplsLdpStdMIB -- MPLS-LDP-STD-MIB [RFC3815]
     |  |    |
     |  |    +- mplsLdpGenericStdMIB -- MPLS-LDP-GENERIC-STD-MIB
     |  |    |
     |  |    +- mplsFTNStdMIB -- MPLS-FTN-STD-MIB [RFC3814]
     |  |    |
     |  |    +- gmplsTCStdMIB -- GMPLS-TC-STD-MIB [RFC4801]
     |  |    |
     |  |    +- gmplsTeStdMIB -- GMPLS-TE-STD-MIB [RFC4802]
     |  |    |
     |  |    +- gmplsLsrStdMIB -- GMPLS-LSR-STD-MIB [RFC4803]
     |  |    |
     |  |    +- gmplsLabelStdMIB -- GMPLS-LABEL-STD-MIB [RFC4803]
     |  |
     |  +- teLinkStdMIB -- TE-LINK-STD-MIB [RFC4220]
     |  |
     |  +- pwStdMIB -- PW-STD-MIB [RFC5601]
     |
     +- ianaGmpls -- IANA-GMPLS-TC-MIB [RFC4802]
     |
     +- ianaPwe3MIB -- IANA-PWE3-MIB [RFC5601]
     |
     +- pwEnetStdMIB -- PW-ENET-STD-MIB [RFC5603]
     |
     +- pwMplsStdMIB -- PW-MPLS-STD-MIB [RFC5602]
     |
     +- pwTDMMIB -- PW-TDM-MIB [RFC5604]
     |
     +- pwTcStdMIB -- PW-TC-STD-MIB [RFC5542]

   Note: The OIDs for MIB modules are assigned and managed by IANA.
   They can be found in the referenced MIB documents.

5.2.2. Textual Convention Modules

   MPLS-TC-STD-MIB [RFC3811] contains the Textual Conventions for
   Multiprotocol Label Switching (MPLS) networks.  These Textual
   Conventions should be imported by MIB modules which manage MPLS
   networks.

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5.2.3. Mapping Data to LSPs

   MPLS is a packet switching protocol that operates between the
   Network layer and the data link layer in the OSI model.

   There is a clean separation between the control and forwarding
   planes in the MPLS protocol. This helps in easy portability and
   extensibility to the forwarding functions.

   A router which supports MPLS is known as a "Label Switching Router",
   or LSR. An LSR implements the control and forwarding plane of MPLS.

   The LSR "control plane" provides information in terms of label
   bindings which are part of the information used to populate
   forwarding tables in an LSR.  An LSR determines which label bindings
   to seek and retain based on configuration and other information.

   The LSR forwarding plane then uses an index which is the incoming
   interface and label (usually of 20-bit length) to forward the
   packet.

   Each entry in this forwarding table corresponds to a forwarding
   equivalence class (FEC). This can be loosely defined as the set of
   characteristics that are being shared by the packets which will be
   forwarded in a similar fashion and may share the same label.

   MPLS packets are encapsulated by one more more label entries
   referred to as the label stack. Each label stack entry consists of a
   label, the 3 TC-bits for classifying the Traffic Class, the bottom of
   stack bit, and TTL.

   The ingress and the egress devices of the MPLS network are called
   Label Edge routers. These routers "Push" an MPLS label into an
   incoming packet and "pop" off the MPLS label from an outgoing packet
   respectively.

   At the ingress when an unlabeled packet enters, one or more label
   stack entries are (each label stack with one or more labels) is
   prefixed to this packet based on its FEC as discussed above. In
   addition, the "MPLS-specific" L2 encapsulation  (including, for
   instance, the MPLS PID) is also added at the ingress. Then the packet
   is sent to the next-hop router for further processing. The next-hop
   router examines the topmost label in the label stack and then does a
   swap, 'push' or 'pop' operations based on the contents.

   A label stack entry can be 'popped' or removed from the top of the
   label stack or a label stack entry is 'pushed' or inserted into the
   top of the stack based on the FEC information.

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   When a 'swap' operation is executed, the topmost label stack entry is
   replaced with a different one and the depth of the label stack
   remains the same. After the swap the packet is forwarded based on the
   new entry.

5.2.4. Label Switching Router Modules

   MPLS-LSR-STD-MIB [RFC3813] describes the managed objects for modeling
   a Multiprotocol Label Switching (MPLS) [RFC3031] LSR.

   MPLS-TP is specific to the use of MPLS in transport networks.
   According to [RFC5654] multipoint-to-point LSPs do not form part of
   MPLS-TP, so multipoint-to-point cross connects are not configured in
   this MIB module for use in MPLS-TP.

5.2.5. Label Switched Path Modules

   The path taken through the MPLS domain by a packet is referred to as
   a label switched path (LSP). It is possible that this path may not be
   understood or completely stored in one LSR within the MPLS domain.

   This label switched path can be programmed using a variety of
   mechanisms. These include manual programming and using a signalling
   protocol.

   RSVP-TE (Resource reservation protocol for Traffic Engineering) is
   normally used for signalling LSPs used for Traffic Engineering.


5.2.6. Pseudowire Modules

   The PW (Pseudowire) MIB modules architecture provides a layered
   modular model into which any supported emulated service can be
   connected to any supported packet switched network (PSN) type.  This
   specific MIB module provides the glue for mapping between the
   emulated service onto the native PSN service. As such, the defining
   of a PW emulated service requires the use of at least three types of
   MIB modules.

   Starting from the emulated service, the first type is a service-
   specific module, which is dependent on the emulated signal type.
   These modules are defined in other documents.

   The second type is this module, the PW-STD-MIB module, which
   configures general parameters of the PW that are common to all types
   of emulated services and PSN types.

   The third type of module is a PSN-specific module.  There is a
   different module for each type of PSN.  These modules associate the
   PW with one or more "tunnels" that carry the service over the PSN.
   These modules are defined in other documents.

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   PW-STD-MIB [RFC5601] defines a MIB module that can be
   used to manage pseudowire (PW) services for transmission over a
   Packet Switched Network (PSN) [RFC3931] [RFC4447].  This MIB module
   provides generic management of PWs that is common to all types of
   PSN and PW services defined by the IETF PWE3 Working Group.

   PW-MPLS-STD-MIB [RFC5602] describes a model for managing pseudowire
   services for transmission over different flavors of MPLS tunnels.
   The general PW MIB module [RFC5601] defines the parameters global to
   the PW regardless of the underlying Packet Switched Network (PSN)
   and emulated service.  This document is applicable for PWs that use
   MPLS PSN type in the PW-STD-MIB.

   This document describes the MIB objects that define pseudowire
   association to the MPLS PSN, in a way that is not specific to the
   carried service.

   Together, [RFC3811] and [RFC3812] describe the modeling of an MPLS
   tunnel, and a tunnel's underlying cross-connects.  This MIB module
   supports MPLS-TE PSN, non-TE MPLS PSN (an outer tunnel created by the
   Label Distribution Protocol (LDP) or manually), and MPLS PW label
   only (no outer tunnel).

   PW-ENET-STD-MIB [RFC5603] describes a model for managing Ethernet
   pseudowire services for transmission over a PSN. This MIB module is
   generic and common to all types of PSNs supported in the Pseudowire
   Emulation Edge-to-Edge (PWE3) architecture [RFC3985], which describes
   the transport and encapsulation of L1 and L2 services over supported
   PSN types.

   In particular, the MIB module associates a port or specific VLANs on
   top of a physical Ethernet port or a virtual Ethernet interface (for
   Virtual Private LAN Service (VPLS)) to a point-to-point PW.  It is
   complementary to the PW-STD-MIB [RFC5601], which manages the generic
   PW parameters common to all services, including all supported PSN
   types.

   PW-TDM-MIB [RFC5604] describes a model for managing TDM pseudowires,
   i.e., TDM data encapsulated for transmission over a Packet Switched
   Network (PSN).  The term TDM in this document is limited to the
   scope of Plesiochronous Digital Hierarchy (PDH).  It is currently
   specified to carry any TDM Signals in either Structure Agnostic
   Transport mode (E1, T1, E3, and T3) or in Structure Aware
   Transport mode (E1, T1, and NxDS0) as defined in the Pseudowire
   Emulation Edge-to-Edge (PWE3) TDM Requirements document [RFC4197].

   The PW MIB modules architecture provides a layered modular model
   into which any supported emulated service can be connected to any
   supported PSN type.  This specific MIB module provides the glue for
   mapping between the emulated service onto the native PSN service.  As
   such, the defining of a PW emulated service requires the use of at
   least three types of MIB modules.

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5.2.7. Routing and Traffic Engineering

   In MPLS traffic engineering, its possible to specify explicit routes
   or choose routes based on QOS metrics in setting up a path such that
   some specific data can be routed around network hot spots.

   MPLS-TE-STD-MIB [RFC3812] describes managed objects for modeling a
   Multiprotocol Label Switching (MPLS) [RFC3031] based traffic
   engineering.  This MIB module should be used in conjunction with the
   companion document [RFC3813] for MPLS based traffic engineering
   configuration and management.

5.2.8. Resiliency

   MPLS Fast Reroute is a local restoration network resiliency mechanism
   in MPLS TE for link and node protection. Two different modes of local
   protection are described in the [RFC4090] to protect LSP.

   o One-to-One Backup
   o Facility Backup

   Facility backup uses label stacking to reroute multiple protected TE
   LSPs using a single backup TE LSP. One-to-one backup does not use
   label stacking, and every protected TE LSP requires a dedicated
   backup TE LSP.

   MPLS-FRR-GENERAL-STD-MIB [draft-ietf-mpls-fastreroute-mib-14]
   contains objects that apply to any MPLS LSR implementing MPLS TE fast
   reroute functionality.

   MPLS-FRR-ONE2ONE-STD-MIB [draft-ietf-mpls-fastreroute-mib-14]
   contains objects that apply to one-to-one backup method.

   MPLS-FRR-FACILITY-STD-MIB [draft-ietf-mpls-fastreroute-mib-14]
   contains objects that apply to facility backup method.

5.2.9. Fault Management and Performance Management

   MPLS manages the LSP and Pseudowire faults through LSP ping
   [RFC4379], VCCV [RFC5085], BFD for LSPs [RFC5884] and BFD for VCCV
   [RFC5885] tools.

   There is no MIB management model currently available for the above
   fault management tools.

   There is no performance management tool currently available for MPLS.


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5.2.10. MIB Module Interdependencies

   This section provides an overview of the relationship between the
   MPLS MIB modules for managing MPLS networks. More details of these
   relationships are given below.

   The relationship "A --> B" means A depends on B and that MIB module
   A uses an object, object identifier, or textual convention defined
   in MIB module B, or that MIB module A contains a pointer (index or
   RowPointer) to an object in MIB module B.


   +-------> MPLS-TC-STD-MIB <-----------------------------------------+
   |            ^                                                      |
   |            |                                                      |
   |         MPLS-LSR-STD-MIB <--------------------------------+       |
   |                                                           |       |
   +<----------------------- MPLS-LDP-STD-MIB ---------------->+       |
   |                                    ^                      |       |
   |                                    |                      |       |
   +<-- MPLS-LDP-GENERIC-STD-MIB ------>+                      |       |
   |                                                           |       |
   +<------ MPLS-FTN-STD-MIB ---------+----------------------->+       |
   |                 ^                |                                |
   |                 |                |                                |
   +<------------- MPLS-TE-STD-MIB  ->+                                |
                              ^       |  GMPLS-TC-STD-MIB ------------>+
                              |       |    ^                           |
                              |       |    |                           |
                              |   +---+    +<-- GMPLS-LABEL-STD-MIB -->+
                              |   |   ^    ^      ^                    |
                              |   |   |    |      |                    |
   +----> PW-TC-STD-MIB       |   |  GMPLS-LSR-STD-MIB --------------->+
   |                          |   |      ^       ^                     |
   |                          |   |      |       |                     |
   |   IANA-PWE3-MIB          |   |      |       | IANA-GMPLS-TC-MIB   |
   |         ^                |   |      |       |    ^                |
   |         |                |   |      |       |    |                |
   |         |                |   +<--- GMPLS-TE-STD-MIB ------------->+
   |         |                |   ^                                    |
   +<--- PW-STD-MIB <------+  |   |                                    |
   |                       |  |   |                                    |
   +<--- PW-ENET-STD-MIB ->+  |   |                                    |
   |                       ^  |   |                                    |
   |                       |  |   |                                    |
   +<---------------- PW-MPLS-STD-MIB -------------------------------->+

   Thus:

   -  All the MPLS MIB modules depend on MPLS-TC-STD-MIB.

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   -  All the GMPLS MIB modules depend on GMPLS-TC-STD-MIB.

   -  All the PW MIB modules depend on PW-TC-STD-MIB.

   -  MPLS-LDP-STD-MIB, MPLS-TE-STD-MIB, MPLS-FTN-STD-MIB,
      GMPLS-LSR-STD-MIB, and PW-MPLS-STD-MIB contain references to
      objects in MPLS-LSR-STD-MIB.

   -  MPLS-LDP-GENERIC-STD-MIB contains references to objects in
      MPLS-LDP-STD-MIB.

   -  MPLS-FTN-STD-MIB, PW-MPLS-STD-MIB, and GMPLS-TE-STD-MIB contain
      references to objects in MPLS-TE-STD-MIB.

   -  PW-MPLS-STD-MIB, and PW-ENET-STD-MIB contains references to
      objects in PW-STD-MIB.

   -  PW-STD-MIB contains references to objects in IANA-PWE3-MIB.

   -  GMPLS-TE-STD-MIB contains references to objects in
      IANA-GMPLS-TC-MIB.

   -  GMPLS-LSR-STD-MIB contains references to objects in
      GMPLS-LABEL-STD-MIB.

   Note that there is a textual convention (MplsIndexType) defined in
   MPLS-LSR-STD-MIB that is imported by MPLS-LDP-STD-MIB.

5.2.11. Dependencies on External MIB Modules

   In addition to the MPLS management overview [RFC4221]
   section 4.12 (Dependencies on External MIB Modules), some of the
   existing MPLS MIBs, PW MIBs and GMPLS MIBs are re-used with
   extensions for achieving the MPLS-TP functionality.

   MPLS MIB modules have dependencies with the TE-LINK-STD-MIB
   for maintaining the traffic engineering information.

   MPLS MIB modules depend on the CSPF module to get the paths for MPLS
   tunnel to traverse to reach the end point of the tunnel and BFD
   module to verify the data-plane failures of LSPs and PWs.

   Finally, all of the MIB modules import standard textual conventions
   such as integers, strings, timestamps, etc., from the MIB modules in
   which they are defined.

   This is business as usual for a MIB module and is not discussed
   further in this document.



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6. Applicability of MPLS MIB modules to MPLS-TP

   [RFC5951] specifies the requirements for the management of
   equipment used in networks supporting an MPLS-TP. It also details the
   essential network management capabilities for operating networks
   consisting of MPLS-TP equipment.

   [RFC5950] provides the network management framework for
   MPLS-TP. The document explains how network elements and networks that
   support MPLS-TP can be managed using solutions that satisfy the
   requirements defined in [RFC5951]. The relationship between
   MPLS-TP management and OAM is described in the MPLS-TP framework
   [RFC5950] document.

   Fault management and performance management form key parts of
   Operations, Administration, and Maintenance (OAM) function. MPLS-TP
   OAM is described in [MPLS-TP-OAM-FWK].

   This section also provides the information about the extensions of
   existing MPLS MIB modules for MPLS-TP and the new MPLS-TP MIB
   modules.

6.1 Gap Analysis

6.1.1 MPLS-TP Tunnel

   MPLS-TP tunnel table MPLSTP-STD-MIB is an extension of
   MPLS tunnel table [RFC3812] to support MPLS-TP requirements.
   Tunnel identifiers are defined based on [MPLS-TP-IDENTIFIERS].

6.1.2 MPLS-TP Pseudowire

   MPLS-TP Pseudowire table MPLSTP-STD-MIB is an extension of
   Pseudowire table MPLS-PW-STD-MIB to support MPLS-TP requirements.
   Pseudowire identifiers are defined based on [MPLS-TP-IDENTIFIERS].

6.1.3 MPLS-TP Sections

   This section needs to be updated with the section layer network
   managed objects based on the draft-ietf-mpls-tp-data-plane-04.txt
   (Section 3.2.) draft.

6.1.4 MPLS-TP OAM

   MPLS-LSP-PING-STD-MIB describes managed objects used to model and
   manage the MPLS LSP ping [RFC4379]. LSP ping is used for
   connectivity verification and fault isolation in an MPLS LSPs.

   PW-VCCV-STD-MIB describes managed objects used to model and manage
   the VCCV [RFC5085]. VCCV used for end-to-end fault detection and
   diagnostics for a Pseudowire.

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   BFD-MPLS-STD-MIB describes the managed objects for modeling the
   BFD for MPLS LSPs [RFC5884]. BFD for LSPs used for detecting
   MPLS LSP data plane failures.

   BFD-PW-VCCV-STD-MIB describes the managed objects for modeling
   the BFD for Pseudowires [RFC5885]. BFD for Pseudowires used for
   detecting data plane failures.

   MPLS-LSP-PING-STD-MIB, PW-VCCV-STD-MIB, BFD-MPLS-STD-MIB and
   BFD-PW-VCCV-STD-MIB are newly defined for MPLS. The new MPLS-TP
   managed objects for LSP ping and BFD are based on
   draft-ietf-mpls-tp-lsp-ping-bfd-procedures-00.

   All MPLS-TP managed for OAM is defined in the MPLSTP-OAM-STD-MIB.

   MPLSTP-TC-STD-MIB describes the textual conventions used for MPLS-TP.

   MPLSTP-STD-MIB describes managed objects used to model and manage
   the new extensions for LSPs, section and Pseudowires for IP and
   non-IP packet based MPLS-TP transport networks.

   The following MPLS-TP OAM functionalities can be achieved using the
   MPLSTP-OAM-STD-MIB mib extensions:

   o Continuity Check and Connectivity Verification,
   o Alarm Reporting, Diagnostic,
   o Route Tracing,
   o Loopback tool,
   o Lock Instruct,
   o Lock Reporting Remote Defect Indication,
   o Client Failure Indication,
   o Packet Loss Measurement and
   o Packet Delay Measurement

   MPLS-TP OAM managed objects are defined based on the drafts:

   o draft-ietf-mpls-tp-oam-requirements-06,
   o draft-ietf-mpls-tp-oam-framework-06 and
   o draft-ietf-mpls-tp-identifiers-01

6.1.5 MPLS-TP Protection Switching

   An important aspect that MPLS-TP technology provides is protection
   switching. In general, the mechanism of protection switching
   can be described as the substitution of a protection or standby
   facility for a working or primary facility. An MPLS-TP protection
   switching can be managed with the following parameters:



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   o Topology (linear, ring, mesh)
   o Protection architecture (1+1, 1:1, or others as defined in
     different topologies)
   o Switching type (unidirectional, bidirectional)
   o Operation mode (revertive, non-revertive)
   o Automatic protection channel
   o Protection state
   o Position of the switch
   o Timer values (hold-off, Wait-to-Restore)
   o Failure of protocol

   Among those parameters for protection switching, the topology on
   that a  protection switching applies has the most significant
   influence on the other parameters. Besides, the mechanism of a
   particular protection switching heavily depends on its topology.
   Therefore, three MIB modules are to be defined to model and
   manage each of three different topologies protection switching.

   MPLSTP-LPS-STD-MIB describes managed objects used to model and
   manage the linear protection switching.

   MPLSTP-RPS-STD-MIB describes managed objects used to model and
   manage the ring protection switching.

   MPLSTP-MPS-STD-MIB describes managed objects used to model and
   manage the mesh protection switching.

6.1.6 MIB Module Interdependencies

   This section provides an overview of the relationship between
   the MPLS-TP MIB modules. More details of these relationships
   are given below.

   The arrows in the following diagram show a 'depends on'
   relationship. A relationship "MIB module A depends on MIB module
   B" means that MIB module A uses an object, object identifier, or
   textual convention defined in MIB module B, or that MIB module A
   contains a pointer (index or RowPointer) to an object in MIB
   module B.












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   +-------------->MPLSTP-TC-STD-MIB <--------------------------+
   |                                                            |
   |       MPLS-TE-STD-MIB  PW-STD-MIB                          |
   |              ^          ^                                  |
   |              |          |                                  |
   +<----------- MPLSTP-STD-MIB <-------------------------------+
   |                 ^                                          |
   |                 |     +---------> MPLS-LSP-PING-STD-MIB    |
   |                 |     ^             ^         ^            |
   |                 |     |             |         |            |
   |                 |     |   PW-VCCV-STD-MIB     |            |
   |                 |     |    ^        ^         |            |
   |                 |     |    |        |         |            |
   |                 | BFD-MPLS-STD-MIB  |         |            |
   |                 |   ^    +----------+         |            |
   |                 |   |    ^                    |            |
   |                 |   |    |                    |            |
   +<-----------  MPLSTP-OAM-STD-MIB ------------->+            |
                     ^                                          |
                     |                                          |
                     +- MPLSTP-LPS-STD-MIB -------------------->+
                     |                                          |
                     +- MPLSTP-RPS-STD-MIB -------------------->+
                     |                                          |
                     +- MPLSTP-MPS-STD-MIB -------------------->+

  Thus:

   -  All the MPLS-TP MIB modules depend on MPLSTP-TC-STD-MIB.

   -  MPLSTP-OAM-STD-MIB and MPLSTP-PS-STD-MIB contain references to
      objects in MPLSTP-STD-MIB.

   -  MPLSTP-PS-STD-MIB contains references to objects in
      MPLSTP-OAM-STD-MIB.

   -  MPLSTP-STD-MIB contains references to objects in
      MPLS-TE-STD-MIB and PW-STD-MIB.

   -  MPLSTP-OAM-STD-MIB contains references to objects in
      MPLS-LSP-PING-STD-MIB, and
      PW-VCCV-STD-MIB and BFD-MPLS-STD-MIB.

   -  BFD-MPLS-STD-MIB contains references to objects in
      MPLS-LSP-PING-STD-MIB and PW-VCCV-STD-MIB.

   -  PW-VCCV-STD-MIB contains references to objects in
      MPLS-LSP-PING-STD-MIB.



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7. Interfaces

  MPLS-TP can be carried over the existing and evolving physical
  transport technologies such as SONET/SDH, OTN/WDM, and Ethernet.

  The Interfaces Group of IF-MIB [RFC2863] defines generic managed
  objects for managing interfaces.  The MPLS-TP MIB modules make
  references to interfaces so that it can be clearly determined where
  the procedures managed by the MIB modules should be performed.
  Additionally, the MPLS-TP MIB modules (notably MPLS-TE-STD-MIB and
  TE-LINK-STD-MIB, PW-STD-MIB) utilize interface stacking within the
  Interface Group.

  Please refer to section 4. (Node and Interface Identifiers) in
  [MPLS-TP-IDENTIFIERS] for more information on MPLS-TP specific
  interfaces.

7.1. MPLS Tunnels as Interfaces

  mplstpTunnelTable is extended from mplsTunnelTable for achieving the
  MPLS-TP tunnel requirements.

  MPLS Tunnel logical interfaces can be stacked over
  PDH/SDH/OTH/Ethernet physical interfaces. For more information on
  Tunnel interfaces, refer section 11.1 (MPLS Tunnels as Interfaces) of
  RFC-4221.

7.2. Application of the Interfaces Group to TE Links

  TE links can be formed over PDH/SDH/OTH/Ethernet physical interfaces.
  For more information on TE links, Refer section 11.2. Application of
  the Interfaces Group to TE Links of RFC-4221.

7.3. References to Interface Objects from MPLS MIB Modules

  MPLSTP-STD-MIB includes the extensions of Tunnel table, PW table
  for MPLS-TP.

  More information on Tunnel interfaces can be found in the RFC-3812,
  section 8. (Application of the Interface Group to MPLS Tunnels)

  The PW in general is not an ifIndex on its own, for agent
  scalability reasons. The PW is typically associated via
  the PWE3 MIB modules to an ifIndex (physical entity) the PW is
  emulating. Some implementations may manage the PW as an ifIndex in the
  ifTable. A special ifType to represent a PW virtual interface (246)
  will be used in the ifTable in this case. More information on PW
  interfaces can be found in the RFC-5601, section 8 (PW relations to
  the IF-MIB).


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8. Management Options

   It is not the intention of this document to provide instructions or
   advice to implementers of management systems, management agents, or
   managed entities.  It is, however, useful to make some observations
   about how the MIB modules described above might be used to manage
   MPLS systems.

   For MPLS specific management options, refer [RFC4221] Section 12
   (Management Options).

   [Editors Note: MPLS-TP specific management gaps and options will be
   documented in this document and will be referenced here.]


9. Security Considerations

   This document describes the interrelationships amongst the different
   MIB modules relevant to MPLS-TP management and as such does not have
   any security implications in and of itself.

   Each IETF MIB document that specifies MIB objects for MPLS-TP must
   provide a proper security considerations section that explains the
   security aspects of those objects.

   The attention of readers is particularly drawn to the security
   implications of making MIB objects available for create or write
   access through an access protocol such as SNMP.  SNMPv1 by itself is
   an insecure environment.  Even if the network itself is made secure
   (for example, by using IPSec), there is no control over who on the
   secure network is allowed to access the objects in this MIB.  It is
   recommended that the implementers consider the security features as
   provided by the SNMPv3 framework.  Specifically, the use of the
   User-based Security Model STD 62, RFC3414 [RFC3414], and the
   View-based Access Control Model STD 62, RFC 3415 [RFC3415],
   is recommended.

   It is then a customer/user responsibility to ensure that the SNMP
   entity giving access to an instance of each MIB module is properly
   configured to give access to only those objects, and to those
   principals (users) that have legitimate rights to access them.


10. IANA Considerations

   This document makes no requests for IANA action.

11. Acknowledgements

   The authors would like to thank Eric Gray, Thomas Nadeau and Benjamin
   Niven-Jenkins for their valuable comments.

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12. References

12.1 Normative References

   [RFC2863]  McCloghrie, K. and F. Kastenholz, "The Interfaces Group
              MIB using SMIv2", RFC 2863, June 2000.

   [RFC3811]  Nadeau, T. and J. Cucchiara, "Definition of Textual
              Conventions and for Multiprotocol Label Switching (MPLS)
              Management", RFC 3811, June 2004.

   [RFC3812]  Srinivasan, C., Viswanathan, A., and T. Nadeau,
              "Multiprotocol Label Switching (MPLS) Traffic
              Engineering (TE) Management Information Base (MIB)",
              RFC 3812, June 2004.

   [RFC3813]  Srinivasan, C., Viswanathan, A., and T.  Nadeau,
              "Multiprotocol Label Switching (MPLS) Label Switching
              (LSR) Router Management Information Base (MIB)", RFC 3813,
              June 2004.

   [RFC3814]  Nadeau, T., Srinivasan, C., and A.  Viswanathan,
              "Multiprotocol Label Switching (MPLS) FEC-To-NHLFE
              (FTN) Management Information Base", RFC3814, June
              2004.

   [RFC3815]  Cucchiara, J., Sjostrand, H., and Luciani, J.,
              "Definitions of Managed Objects for the
              Multiprotocol Label Switching (MPLS), Label
              Distribution Protocol (LDP)", RFC 3815, June 2004.

   [RFC4220]  Dubuc, M., Nadeau, T., and J. Lang, "Traffic
              Engineering Link Management Information Base", RFC
              4220, November 2005.

   [RFC4221]  Nadeau, T., Srinivasan, C., and A. Farrel,
              "Multiprotocol Label Switching (MPLS) Management
              Overview", RFC 4221, November 2005.

   [RFC4801]  T. Nadeau and A. Farrel, Ed., "Definitions of Textual
              Conventions for Generalized Multiprotocol Label Switching
              (GMPLS) Management", RFC4801, Feb. 2007.

   [RFC4802]  T. D. Nadeau and A. Farrel, "Generalized Multiprotocol
              Label Switching (GMPLS) Traffic Engineering Management
              Information Base", RFC4802, Feb., 2007.

   [RFC4803]  T. D. Nadeau and A. Farrel, "Generalized Multiprotocol
              Label Switching (GMPLS) Label Switching Router (LSR)
              Management Information Base", RFC4803, Feb., 2007.

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   [RFC5542]  Nadeau, T., Ed., Zelig, D., Ed., and O. Nicklass, Ed.,
              "Definitions of Textual Conventions for Pseudowire (PW)
              Management", RFC 5542, May 2009.

   [RFC5601]  Nadeau, T., Ed. and D. Zelig, Ed. "Pseudowire (PW)
              Management Information Base (MIB)", RFC 5601, July 2009.

   [RFC5602]  Zelig, D., Ed., and T. Nadeau, Ed., "Pseudowire (PW) over
              MPLS PSN Management Information Base (MIB)", RFC 5602,
              July 2009.

   [RFC5603]  Zelig, D., Ed., and T. Nadeau, Ed., "Ethernet Pseudowire
              (PW) Management Information Base (MIB)", RFC 5603,
              July 2009.

   [RFC5604]  Nicklass, O., "Managed Objects for Time Division
              Multiplexing (TDM) over Packet Switched Networks (PSNs)",
              RFC5604, July 2009.

12.2 Informative References

   [RFC2578]  McCloghrie, K., Perkins, D., and J. Schoenwaelder,
              "Structure of Management Information Version 2
              (SMIv2)", STD 58, RFC 2578, April 1999.

   [RFC2579]  McCloghrie, K., Perkins, D., and J. Schoenwaelder,
              "Textual Conventions for SMIv2", STD 58, RFC 2579,
              April 1999.

   [RFC2580]  McCloghrie, K., Perkins, D., and J. Schoenwaelder,
              "Conformance Statements for SMIv2", STD 58, RFC 2580,
              April 1999.

   [RFC3031]  Rosen, E., Viswanathan, A., and R. Callon,
              "Multiprotocol Label Switching Architecture", RFC 3031,
              January 2001.

   [RFC3410]  Case, J., Mundy, R., Partain, D. and B. Stewart,
              "Introduction and Applicability Statements for
              Internet-Standard Management Framework", RFC 3410,
              December 2002.

   [RFC3414]  Blumenthal, U. and B. Wijnen, "User-based Security
              Model (USM) for version 3 of the Simple Network
              Management Protocol (SNMPv3)", STD 62, RFC 3414,
              December 2002.

   [RFC3415]  Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based
              Access Control Model (VACM) for the Simple Network
              Management Protocol (SNMP)", STD 62, RFC 3415, December
              2002.

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   [RFC3931]  Lau, J., Townsley, M., and I. Goyret, "Layer Two Tunneling
              Protocol - Version 3 (L2TPv3)", RFC 3931, March 2005.

   [RFC3945]  Mannie, E. et.al., "Generalized Multi-Protocol Label
              Switching (GMPLS) Architecture", IETF RFC 3945, October
              2004.

   [RFC3985]  Bryant, S. and P. Pate, "Pseudo Wire Emulation Edge-to-
              Edge (PWE3) Architecture", RFC 3985, March 2005.

   [RFC4090]  Pan, P., Ed., Swallow, G., Ed., and A. Atlas, Ed., "Fast
              Reroute Extensions to RSVP-TE for LSP Tunnels", RFC 4090,
              May 2005.

   [RFC4197]  Riegel, M., "Requirements for Edge-to-Edge Emulation of
              Time Division Multiplexed (TDM) Circuits over Packet
              Switching Networks", RFC4197, October 2005.

   [RFC4377]  Nadeau, T., Morrow, M., Swallow, G., Allan, D., and S.
              Matsushima, "Operations and Management (OAM) Requirements
              for Multi-Protocol Label Switched (MPLS) Networks",
              RFC 4377, February 2006.

   [RFC4378]  Allan, D. and T. Nadeau, "A Framework for Multi-Protocol
              Label Switching (MPLS) Operations and Management (OAM)",
              RFC 4378, February 2006.

   [RFC4379]  Kompella, K. and G. Swallow, "Detecting Multi-Protocol
              Label Switched (MPLS) Data Plane Failures", RFC 4379,
              February 2006.

   [RFC4447]  Martini, L., Rosen, E., El-Aawar, N., Smith, T., and
              G. Heron, "Pseudowire Setup and Maintenance Using the
              Label Distribution Protocol (LDP)", RFC 4447,
              April 2006.

   [RFC5085]  Nadeau, T. and C. Pignataro, "Pseudowire Virtual
              Circuit Connectivity Verification (VCCV): A Control
              Channel for Pseudowires", RFC 5085, December 2007.

   [RFC5654]  Niven-Jenkins, B., et al, "MPLS-TP Requirements",
              RFC5654, September 2009.

   [RFC5884]  Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow,
              "Bidirectional Forwarding Detection (BFD) For MPLS
              Label Switched Paths (LSPs)", RFC 5884, June 2010.



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   [RFC5885]  Nadeau, T. and C. Pignataro, "Bidirectional
              Forwarding Detection (BFD) for the Pseudowire
              Virtual Circuit Connectivity Verification (VCCV)",
              RFC5885, June 2010.

   [RFC5950]  Gray, E., Mansfield, S., Lam, K.,
              "MPLS-TP Network Management Framework", RFC 5950,
              September 2010.

   [RFC5951]  Gray, E., Mansfield, S., Lam, K., "MPLS TP
              Network Management Requirements", RFC 5951, September
              2010.

   [MPLS-TP-IDENTIFIERS] Bocci, M., Swallow, G., "MPLS-TP Identifiers"
              draft-ietf-mpls-tp-identifiers-02, July 2010.

   [MPLS-TP-OAM-FWK] Busi, I. and B. Niven-Jenkins, "MPLS-TP OAM
              Framework and Overview", 2009,
              <draft-ietf-mpls-tp-oam-framework>.


14. Authors' Addresses

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

   Daniel King
   Old Dog Consulting
   UK
   Email: daniel@olddog.co.uk

   Venkatesan Mahalingam
   Aricent
   India
   Email: venkatesan.mahalingam@aricent.com

   Scott Mansfield
   Ericsson
   300 Holger Way
   San Jose, CA  95134
   US
   Phone: +1 724 931 9316
   Email: scott.mansfield@ericsson.com

   Jeong-dong Ryoo
   ETRI
   161 Gajeong, Yuseong, Daejeon, 305-700, South Korea
   Phone: +82 42 860 5384
   Email: ryoo@etri.re.kr

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   A S Kiran Koushik
   Cisco Systems Inc.
   Email: kkoushik@cisco.com















































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