LIME Working Group                                             Y. Tochio
Internet-Draft                                                   Fujitsu
Intended status: Informational                           H. van Helvoort
Expires: October 29, 2015                                 Hai Gaoming BV
                                                                  L. Xia
                                                                  Huawei
                                                          April 27, 2015


Gap Analysis for Layer and Technology Independent OAM Management in the
                        Multi-Layer Environment
                 draft-txh-opsawg-lime-gap-analysis-03

Abstract

   This draft analyses the existing management plane OAM related works
   in different SDOs, against the key objectives of Layer Independent
   OAM Management (LIME), to find the gap between them.  The results can
   be used as the guidance for further work.  This gap analysis is not
   targeted at L0-L2 transport OAM in ITU-T, either technology specific
   or generic across those technologies.  Rather, it is intended to
   leverage knowledge from that domain for the benefit of developing
   generic layer independent OAM management for L3-L7 (and L2.5 MPLS
   OAM).

Status of This Memo

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

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on April 29, 2015.

Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.





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   This document is subject to BCP 78 and the IETF Trust's Legal
   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
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions used in this document . . . . . . . . . . . . . .   3
     2.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Existing OAM Related Works  . . . . . . . . . . . . . . . . .   4
     3.1.  Survey of ITU-T Work from L0-L2 . . . . . . . . . . . . .   5
       3.1.1.  Generic L0-L2 . . . . . . . . . . . . . . . . . . . .   5
       3.1.2.  Technology Specific L0-L2 . . . . . . . . . . . . . .   5
     3.2.  Management Information Models . . . . . . . . . . . . . .   5
     3.3.  IEEE CFM MIB  . . . . . . . . . . . . . . . . . . . . . .   6
     3.4.  MEF SOAM FM and PM MIB  . . . . . . . . . . . . . . . . .   6
     3.5.  IETF Technology-specific MIB Series . . . . . . . . . . .   7
     3.6.  MEF CFM and SOAM YANG Data Model  . . . . . . . . . . . .   7
     3.7.  YANG Model for OAM Management and Technology-specific
           extensions  . . . . . . . . . . . . . . . . . . . . . . .   7
     3.8.  Discussion  . . . . . . . . . . . . . . . . . . . . . . .   8
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   5.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   8
   6.  Normative References  . . . . . . . . . . . . . . . . . . . .   8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   Operations, Administration, and Maintenance (OAM) mechanisms are
   critical building blocks in network operations that are used for
   service assurance, fulfillment, or service diagnosis,
   troubleshooting, and repair.  The current practice is maintenance and
   troubleshooting are achieved per technology and per layer.  The
   operation process can be very cumbersome.  At present, within the
   L0-L2 technology domains, considerable effort has been expended in
   ITU-T to establish a coherent approach to OAM, including generic
   layer independent principles.

   Due to this fact, [I-D.edprop-opsawg-multi-layer-oam-ps] discusses a
   valuable direction in management plane by establishing a coherent
   approach to OAM information from L2.5-L7 using a centralized
   management entity and have a unified and consistent OAM view of



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   multi-layer networks.  Operators can rely on consolidated OAM
   management to correlate different layer OAM information (e.g., fault,
   defects and network failure), and quickly identify the faulty element
   with its layer information in the network path.  Note that current
   LIME work focuses on layer-independent and technology-independent
   configuration, reporting and presentation for OAM mechanisms in the
   context of IP, MPLS, BFD, pseudowires, and Transparent
   Interconnection of Lots of Links (TRILL) technology developed by
   IETF.  The second important objective of LIME is to achieve a layer
   and technology independent OAM view of a network and allow management
   applications present to the user an abstract view of this network and
   its supporting layers that is strictly topological, free of any
   technology specific information.  This means an abstract and generic
   OAM management model in the management plane should be utilized (with
   extensions as appropriate to L2.5-L7), from which OAM specific views
   can be established, and technology-specific OAM data models can be
   developed by mapping from the information model view.  A generic OAM
   management model can provide a consistent configuration, reporting,
   and presentation for the OAM mechanisms.  It also can mitigate the
   problem related to specific OAM technology dependency.  [I-D.king-
   opsawg-lime-multi-layer-oam-use-case] lists the key use case for LIME
   application.

   This draft analyses the existing management plane OAM related work in
   several SDOs, against the key objectives of LIME, to find the gap
   between them.  The results can be used as the guidance for further
   work.

2.  Conventions used in this document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC2119 [RFC2119].

2.1.  Terminology

   DM Data Model


   EMS  Element Management System


   IM Information Model


   NMS  Network Management System





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   MP Maintenance Point [802.1Q]


   MEG  Maintenance Entity Group [G.8013] [RFC6371]


   MEP  MEG End Point [G.8013] [RFC6371]


   MIP  MEG Intermediate Point [G.8013] [RFC6371]


   ME Maintenance Entity [G.8013] [RFC6371]


   MD Maintenance Domain [802.1Q]


   MPLS  Multiprotocol Label Switching


   NE Network Element


   NVO3  Network Virtualization Overlays


   OAM  Operations, Administration, and Maintenance [RFC6291]


   LIME  Layer Independent OAM Management [I-D.edprop-opsawg-multi-
      layer-oam-ps]


   SFC  Service Function Chaining


   SFF  Service Function Forwarder


   SDO  Standard Developing Organization


3.  Existing OAM Related Works







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3.1.  Survey of ITU-T Work from L0-L2

3.1.1.  Generic L0-L2

   [G.800] and [G.805] specify the unified and generic functional
   architecture of transport networks.  [G.806] specifies the generic
   processing of transport equipment functions, including handling of
   OAM, defect correlation, and alarm suppression, etc.  [G.7710]
   specifies the generic management requirements for configuration,
   fault, and performance (i.e. the C, F, P of FCAPS).  [G.gim] is on-
   going work in ITU-T to specify the generic management information
   model for L0-L2 transport networks.

3.1.2.  Technology Specific L0-L2

   [G.803], [G.872], [G.8010] and [G.8110.1] specify the functional
   architecture respectively for SDH, OTN, Ethernet, MPLS-TP transport
   networks.  [G.783], [G.798], [G.8021] and
   [G.8121]/[G.8121.1]/[G.8121.2] specify respectively the processing of
   transport equipment functions for SDH, OTN, Ethernet, MPLS-TP,
   including handling of OAM, defect correlation, and alarm suppression,
   etc.  [G.784], [G.874], [G.8051] and [G.8151] specify respectively
   the management requirements for configuration, fault, and performance
   (i.e. the C, F, P of FCAPS).  [G.774], [G.874.1], [G.8052] and
   [G.8152] specify respectively the management information model for
   SDH, OTN, Ethernet, MPLS-TP transport networks.

3.2.  Management Information Models

   ITU-T's Recommendation [G.8052] and [G.8152] provide the management
   protocol-neutral information models for managing network elements in
   the Ethernet transport network and MPLS-TP transport network as
   defined in Recommendations [G.8010] and [G.8110.1] respectively.  The
   management information models are derived from the "functional
   models", which describe the data plane behavior and processing.
   Management information models manage the "atomic functions" defined
   in the data plane in transport networks.  They contain the object
   classes for the Ethernet and MPLS-TP NE management.  This includes
   the Termination Point (TP), Maintenance Entity Group (MEG) End Point
   (MEP), MEG Intermediate Point (MIP), Traffic Conditioning & Shaping
   (TCS), Loss Measurement (LM), Delay Measurement (DM), and the general
   Performance Monitoring (PM), Current Data (CD) and History Data (HD).
   [G.8052] has been published.  [G.8152] is still in progress.  There
   is already some degree of consolidation among the /L0 (OTN)
   [G.874.1], (SDH) [G.774]/, /L1 (OTN) [G.874.1], (SDH) [G.774]/ and
   /L2 (Ethernet) [G.8052], (MPLS-TP) [G.8152]/ information models
   specified by these ITU-T recommendations.  In fact, they have a




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   common basis for information model and are not technology-specific
   models any more.

   [MEF-7.1] specifies the EMS-NMS interface profile identifying the
   managed objects (i.e. logical UML objects) needed to support Metro
   Ethernet services.  This specification provides the profile of
   management entities based on ITU-T [Q.840.1], and also provides a
   mapping to the TMF's MTNM 3.5 Ethernet model.  Specifically this
   document adds management support for Service OAM.  The Ethernet
   Service OAM object definitions include common OAM objects (e.g.,
   EthMe, EthMeg, EthMep, ,etc), Fault Management Objects (e.g.,
   Continuity Check, Loopback, etc.), Performance Monitoring Objects
   (e.g., Loss Measurement, Delay Measurement, etc.).

3.3.  IEEE CFM MIB

   The IEEE8021-CFM-MIB MIB Module and IEEE8021-CFM-V2-MIB MIB module
   are CFM MIB modules for managing IEEE CFM in [802.1Q].  The former
   document defines all the MIB objects that used to read, create,
   modify, and delete OAM related information (i.e., CFM Stack Table, MD
   Table, MA Table, MEP Table, LinkTrace Reply Table, MEP DB Table,
   Notifications Table, etc).  The latter document defines CFM V2 module
   for managing IEEE CFM.  It contains objects that replace those
   deprecated in the IEEE8021-CFM-MIB module (i.e., CFM Stack Table, CFM
   Vlan Table, CFM Default MD Level Table, etc).

3.4.  MEF SOAM FM and PM MIB

   [MEF-31] defines the MIB modules for MEF Service OAM Fault Management
   (FM).  This document includes two MIBs necessary to support the MEF
   SOAM FM functionality: the MEF-SOAM-TC-MIB that includes the Textual
   Conventions (TC) for the SOAM MIB family and the MEF-SOAM-FM-MIB that
   includes extensions to Connectivity Fault Management (CFM) as
   developed in IEEE [802.1Q], including MIBs found in [IEEE 802.1Q] and
   [IEEE 802.1ap], and enhanced by ITU-T [Y.1731] to support the SOAM FM
   functions as presented in the [MEF-30] specification.  It includes
   the SOAM FM MIB objects such as mefSoamNet, mefSoamMeg, mefSoamMep,
   mefSoamCc, mefSoamAis, mefSoamLb, etc.

   [MEF-36] specifies the Performance Monitoring (PM) MIB necessary to
   manage SOAM implementations that satisfy the Service OAM requirements
   and framework specified by [MEF-17], the Service OAM Performance
   Monitoring requirements as specified by [MEF-35], and the Service OAM
   management objects as specified by [MEF-7.1] which are applicable to
   Performance Monitoring functions.  Two non-MEF documents serve as the
   baseline documents for this work: ITU-T [G.8013] and IEEE [802.1Q].
   The SOAM PM MIB is divided into a number of different object




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   groupings: the PM MIB MEP Objects, PM MIB Loss Measurement Objects,
   PM MIB Delay Measurement Objects, and SOAM PM Notifications.

3.5.  IETF Technology-specific MIB Series

   IETF specifies a series MIB module for various technologies, which
   includes: [RFC7331] for BFD MIB, [RFC4560] for PING MIB, [MPLS-TP OAM
   ID MIB] for MPLS-TP MIB, etc.

   All these documents are technology-specific and limited to L1, L2,
   L3.  The OAM MIB definition above L3 (i.e., SFC service layer) is
   still missing in IETF.

3.6.  MEF CFM and SOAM YANG Data Model

   SOAM CFM YANG module [MEF-38] is an important work that defines the
   managed objects necessary to support SOAM CFM functionality by using
   the IETF YANG Module Language [RFC6020].  This YANG module contains
   the management data definitions for the management of Ethernet
   Services OAM for Connectivity Fault Management.

   [MEF-39] provides the YANG module that supports the Ethernet Service
   OAM (SOAM) Performance Monitoring functions.  This YANG module
   contains the management data definitions for the management of
   Ethernet Services OAM for Performance Monitoring and extends the
   Connectivity Fault Management (CFM) YANG modules.

3.7.  YANG Model for OAM Management and Technology-specific extensions

   [I-D.tissa-lime-yang-oam-model], [I-D.wang-lime-rpc-yang-oam-
   management] are two IETF work that creates a YANG unified data models
   for OAM that is based on IEEE CFM model.  [I-D. tissa-lime-yang-oam-
   model] defines a YANG [RFC6020] data model for Layer independent OAM
   Management implementations that can be applied to various network
   technologies.  [I-D.wang-lime-rpc-yang-oam-management] describes the
   abstract notification and rpc command to the YANG Module which is
   complementary to the one defined in the [I-D.tissa-lime-yang-oam-
   model].  These efforts are focused on the management plane of OAM and
   should be complemented by an accompanying data-plane and/or control-
   plane work.  It may require also some extensions to support wider
   variety of functions and technologies.

   [I-D.tissa-nvo3-yang-oam] extends the Generic YANG model defined in
   [I-D.tissa-lime-yang-oam-model] for OAM with NVO3 technology
   specifics and presents Yang Module for NVO3 OAM.

   [I-D.xia-sfc-yang-oam] extends the Generic YANG model defined [I-
   D.tissa-lime-yang-oam-model], [I-D.wang-lime-rpc-yang-oam-management]



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   for OAM with SFC technology specifics and presents YANG Module for
   SFC OAM.

   [I-D.wang-bfd-yang-oam]extends the Generic YANG model defined in [I-
   D.tissa-lime-yang-oam-model], [I-D.wang-lime-rpc-yang-oam-management]
   for OAM with BFD technology specifics and present YANG Module for BFD
   OAM.

3.8.  Discussion

   Until now, all the OAM models and operations in the management plane
   for L3-L7 are technology dependent and limited to one specific layer.
   One point which should be noticed is that the information models
   specified for transport networks (L0/L1/L2, [G.874.1], [G.8052],
   [G.8152] ) by the ITU-T have received some degree of consolidation,
   and are not technology dependent. [I-D. lam-lime-summary-l0-l2-
   layer-independent] provides the summary on this point.


4.  Security Considerations

   TBD.

5.  Acknowledgements

   The authors would like to thank for Eve Varma, Maarten Vissers for
   their valuable comments and thoughtful inputs to this draft regarding
   ITU-T OAM works in L0-L2.

6.  Normative References

   [G.774]    "Synchronous digital hierarchy (SDH) - Management
              information model for the network element view", ITU-T
              G.774, February 2001.

   [G.783]    "Characteristics of synchronous digital hierarchy (SDH)
              equipment functional blocks", ITU-T G.783, March 2006.

   [G.784]    "Management aspects of synchronous digital hierarchy (SDH)
              transport network elements", ITU-T G.784, March 2008.

   [G.798]    "Characteristics of optical transport network hierarchy
              equipment functional blocks", ITU-T G.798, December 2012.

   [G.800]    "Unified functional architecture of transport networks",
              ITU-T G.800, February 2012.

   [G.8010]   "Architecture of Ethernet layer networks", ITU-T G.8010,
              February 2004.




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   [G.8013]   "OAM functions and mechanisms for Ethernet based
              networks", ITU-T G.8013/Y.1731, February 2013.

   [G.8021]   "Characteristics of Ethernet transport network equipment
              functional blocks", ITU-T G.8021, January 2015.

   [G.803]    "Architecture of transport networks based on the
              synchronous digital hierarchy (SDH)", ITU-T G.803, March
              2000.

   [G.805]    "Generic functional architecture of transport networks",
              ITU-T G.805, March 2000.

   [G.8051]   "Management aspects of the Ethernet Transport (ET) capable
              network element", ITU-T G.8051, August 2013.

   [G.8052]   "Protocol-neutral management information model for the
              Ethernet transport capable network element", Draft
              Recommendation ITU-T G.8052/Y.1346, August 2013.

   [G.806]    "Characteristics of transport equipment - Description
              methodology and generic functionality", ITU-T G.806,
              February 2012.

   [G.8110.1]
              "Architecture of MPLS Transport Profile (MPLS-TP) layer
              network", ITU-T G.8110.1/Y.1370.1, December 2011.

   [G.8121]   "Characteristics of MPLS-TP equipment functional blocks",
              ITU-T G.8121, November 2013.

   [G.8121.1]
              "Characteristics of MPLS-TP equipment functional blocks
              supporting ITU-T G.8113.1/Y.1372.1 OAM mechanisms", ITU-T
              G.8121.1, November 2013.

   [G.8121.2]
              "Characteristics of MPLS-TP equipment functional blocks
              supporting ITU-T G.8113.2/Y.1372.2 OAM mechanisms", ITU-T
              G.8121.2, November 2013.

   [G.8151]   "Management aspects of the MPLS-TP network element", ITU-T
              G.8151, January 2015.

   [G.8152]   "Protocol-neutral management information model for the
              MPLS-TP network element", Draft Recommendation ITU-T
              G.8152/Y.1375, 2016.




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   [G.872]    "Architecture of optical transport networks", ITU-T G.872,
              Octorber 2012.

   [G.874]    "Management aspects of optical transport network
              elements", ITU-T G.874, August 2013.

   [G.874.1]  "Optical transport network: Protocol-neutral management
              information model for the network element view", ITU-T
              G.874.1, Octorber 2012.

   [I-D.edprop-opsawg-multi-layer-oam-ps]
              Taylor, T., "Problem Statement for Layer and Technology
              Independent OAM in a Multi-Layer Environment", ID draft-
              edprop-opsawg-multi-layer-oam-ps (Exipred), September 2014.

   [I-D.ietf-mpls-tp-oam-id-mib]
              Aldrin, S., Mahalingam, V., Sampath, K., and T. Nadeau,
              "MPLS-TP Operations, Administration, and Management (OAM)
              Identifiers Management Information Base (MIB)", draft-
              ietf-mpls-tp-oam-id-mib-08 (work in progress), February 2015.

   [I-D.king-opsawg-lime-multi-layer-oam-use-case]
              King, D. and D. King, "Use Cases and Requirements for
              Layer Independent OAM Management in multi-layer
              environments", ID draft-king-opsawg-lime-multi-layer-oam-
              use-case (Exipred), September 2014.

   [I-D.tissa-lime-yang-oam-model]
              Senevirathne, T., Finn, N., Kumar, D., Salam, S., and Q.
              Wu, "Generic YANG Data Model for Operations,
              Administration, and Maintenance (OAM)", draft-tissa-lime-
              yang-oam-model-04 (work in progress), April 2015.

   [I-D.tissa-nvo3-yang-oam]
              Senevirathne, T., "YANG Data Model for NVO3 Operations,
              Administration, and Maintenance(OAM)", ID draft-tissa-
              nvo3-yang-oam-00 (Exipred), June 2014.

   [I-D.wang-bfd-yang-oam]
              Wang, Z., "A YANG Data Model for BFD Operations,
              Administration, and Maintenance (OAM)", ID draft-wang-bfd-
              yang-oam-01, March 2015.

   [I-D.wang-lime-rpc-yang-oam-management]
              Wang, Z., "Additional RPC definitions to Generic YANG Data
              Model for layer Independent OAM Management", ID draft-
              wang-lime-rpc-yang-oam-management-02, March 2015.




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   [I-D.xia-sfc-yang-oam]
              Xia, L., "YANG Data Model for SFC Operations,
              Administration, and Maintenance (OAM)", ID draft-xia-sfc-
              yang-oam-02, March 2015.

   [I-D. lam-lime-summary-l0-l2-layer-independent]
              K. Lam., "Existing Support for Network Operations in
              Multilayer Transport Network based upon unified approach to
              OAM (Layer 0 - Layer 2)", ID draft-lam-lime-summary-l0-l2-
              layer-independent-02, April 2015.

   [IEEE802.1Q]
              "Media Access Control (MAC) Bridges and Virtual Bridged
              Local Area Networks", IEEE Std 802.1Q-2014, November 2014.

   [MEF-30]   "Service OAM Fault Management Implementation Agreement",
              MEF 30, January 2011.

   [MEF-31]   "Service OAM Fault Management Definition of Managed
              Objects", MEF 31, January 2011.

   [MEF-35]   "Service OAM Performance Monitoring Implementation
              Agreement", MEF 35, January 2012.

   [MEF-36]   "Service OAM SNMP MIB for Performance Monitoring", MEF 36,
              January 2012.

   [MEF-38]   "Service OAM Fault Management YANG Modules", MEF 38, April
              2012.

   [MEF-39]   "Service OAM Performance Monitoring YANG Module", MEF 39,
              April 2012.

   [MEF-7.1]  "EMS-NMS Information Model -Phase 2", Metro Ethernet Forum
              MEF 7.1, 2009.

   [Q.840.1]  "Requirements and Analysis for NMS-EMS Management
              Interface of Ethernet over Transport and Metro Ethernet
              Network", Draft Recommendation ITU-T Q.840.1, 2007.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", March 1997.

   [RFC6020]  Bjorklund, M., "YANG - A Data Modeling Language for the
              Network Configuration Protocol (NETCONF)", RFC 6020,
              October 2010.

   [RFC6291]  Andersson, L., van Helvoort, H., Bonica, R., Romascanu,
              D., and S. Mansfield, "Guidelines for the use of the "OAM"
              Acronym in the IETF", RFC 6291, June 2011.

   [RFC6371]  Busi, I. and D. Allan, "Operations, Administration, and
              Maintenance Framework for MPLS-Based Transport Networks",
              RFC 6371, September 2011.



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   [RFC7331]  Nadeau, T., Ali, Z., and N. Akiya, "Bidirectional
              Forwarding Detection (BFD) Management Information Base",
              RFC 7331, August 2014.

Authors' Addresses

   Yuji Tochio
   Fujitsu

   Email: tochio@jp.fujitsu.com


   Huub van Helvoort
   Hai Gaoming BV
   The Netherlands

   Email: huubatwork@gmail.com


   Liang (Frank) Xia
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: Frank.xialiang@huawei.com

























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