Network Working Group                                          M. Squire
Request for Comments: 4878                             Hatteras Networks
Category: Standards Track                                      June 2007


                  Definitions and Managed Objects for
    Operations, Administration, and Maintenance (OAM) Functions on
                        Ethernet-Like Interfaces

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The IETF Trust (2007).

Abstract

   This document defines objects for managing Operations,
   Administration, and Maintenance (OAM) capabilities on Ethernet-like
   interfaces conformant to the Ethernet OAM functionality defined in
   the Ethernet in the First Mile (EFM) clauses of the Ethernet
   standards.  The Ethernet OAM functionality is complementary to the
   Simple Network Management Protocol (SNMP) in that it is focused on a
   small set of link-specific functions for directly connected Ethernet
   interfaces.  This document defines objects for controlling those link
   OAM functions and for providing results and status of the OAM
   functions to management entities.

Table of Contents

   1. Introduction ....................................................2
   2. The Internet-Standard Management Framework ......................2
   3. Overview ........................................................3
      3.1. Remote Fault Indication ....................................4
      3.2. Link Monitoring ............................................4
      3.3. Remote Loopback ............................................5
      3.4. Ethernet OAM Protocol Data Units ...........................5
   4. Relation to the Other MIB Modules ...............................5
      4.1. Relation to Other MIB Modules ..............................5
      4.2. Relation to Other EFM MIB Modules ..........................6
      4.3. Mapping of IEEE 802.3ah Managed Objects ....................6
   5. MIB Structure ...................................................7
   6. MIB Definition ..................................................8
   7. Security Considerations ........................................47
   8. IANA Considerations ............................................49
   9. References .....................................................49
      9.1. Normative References ......................................49
      9.2. Informative References ....................................50
   10. Acknowledgments ...............................................51

1.  Introduction

   The IEEE 802.3ah Ethernet in the First Mile (EFM) taskforce added new
   management capabilities to Ethernet-like interfaces.  These
   management capabilities were introduced to provide some basic Ordered
   Aggregate (OA) function on Ethernet media.  The defined functionality
   includes discovery, error signaling, loopback, and link monitoring.
   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in the Internet community
   to manage these new Ethernet interface capabilities.

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 RFC 2119 [RFC2119].

2.  The Internet-Standard Management Framework

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

   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).  This memo specifies a MIB
   module that is compliant to the SMIv2, which is described in STD 58,
   RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580
   [RFC2580].

3.  Overview

   Ethernet networks have evolved over the past 30 years from simple
   LANs to a variety of other applications, including wide-area
   networks.  To address some of these emerging markets, the IEEE
   802.3ah taskforce defined additional clauses in [802.3ah] for the
   IEEE 802.3 standard [802.3-2002] to better address Ethernet
   deployments in the public-access network.  Although Ethernet-access
   deployments were the primary motivation for the taskforce activity,
   the results of the taskforce are not strictly limited to that
   application.  Ethernet OAM can be implemented on Ethernet links that
   are not EFM.

   The Ethernet in the First Mile (EFM) taskforce was focused on four
   somewhat independent objectives to better address Ethernet access
   deployments: optics, copper, Ethernet passive optical networks
   (Ethernet PON, or EPON), and operations, administration, and
   maintenance (OAM).  The optics sub-taskforce developed new optical
   physical layers that better served the long-reach outside plant
   networks typically found in the access network, including developing
   physical layers that operate up to 20 Km and supporting the
   environmental conditions of access deployments.  The copper sub-
   taskforce developed two new physical layers that run Ethernet
   natively over existing twisted pair wires that have been supporting
   voice services for decades.  The EPON sub-taskforce developed a new
   point-to-multipoint Ethernet physical layer, utilizing Ethernet
   framing natively over a time-division multiple-access (TDMA)
   infrastructure.  The OAM sub-taskforce introduced some basic
   management functionality into an Ethernet link to better monitor and
   maintain Ethernet networks in geographically disparate networks.

   This document defines the management objects necessary to integrate
   Ethernet OAM functionality into the SNMP management framework.

   Ethernet OAM is composed of a core set of functions and a set of
   optional functional groups.  The mandatory functions include
   discovery operations (determining if the other end of the link is OA
   capable and what OAM functions it supports), state machine
   implementation, and some critical event flows.  The optional
   functional groups are for (a) link events, (b) remote loopback, and
   (c) variable retrieval and response.  Each optional functional group
   is controlled by a separate MIB table(s).

   Ethernet OAM is complementary with SNMP management in that it
   provides some basic management functions at layer two, rather than
   using layer three and above as required by SNMP over an IP
   infrastructure.  Ethernet OAM provides single-hop functionality in
   that it works only between two directly connected Ethernet stations.
   SNMP can be used to manage the Ethernet OAM interactions of one
   Ethernet station with another.

   Ethernet OAM has three functional objectives, which are detailed in
   the next three sections.  The definition of a basic Ethernet OA
   protocol data unit is given in Section 3.4.

3.1.  Remote Fault Indication

   Remote fault indication provides a mechanism for one end of an
   Ethernet link to signal the other end that the receive path is non-
   operational.  Some Ethernet physical layers offer mechanisms to
   signal this condition at the physical layer.  Ethernet OAM added a
   mechanism so that some Ethernet physical layers can operate in
   unidirectional mode, allowing frames to be transmitted in one
   direction even when the other direction is non-operational.
   Traditionally, Ethernet PHYs do not allow frame transmission in one
   direction if the other direction is not operational.  Using this
   mode, Ethernet OAM allows frame-based signaling of remote fault
   conditions while still not allowing higher-layer applications to be
   aware of the unidirectional capability.  This document includes
   mechanisms for capturing that fault information and reflecting such
   information in objects and notifications within the SNMP management
   framework.

3.2.  Link Monitoring

   Ethernet OAM includes event signaling capability so that one end of
   an Ethernet link can indicate the occurrence of certain important
   events to the other end of the link.  This happens via layer two
   protocols.  This document defines methods for incorporating the
   occurrence of these layer two events, both at the local end and far
   end of the link, into the SNMP management framework.

   Ethernet OAM also includes mechanisms for one Ethernet station to
   query another directly connected Ethernet station about the status of
   its Ethernet interface variables and status.  This document does not
   include mechanisms for controlling how one Ethernet endpoint may use
   this functionality to query the status or statistics of a peer
   Ethernet entity.

3.3.  Remote Loopback

   Remote loopback is a link state where the peer Ethernet entity echoes
   every received packet (without modifications) back onto the link.
   Remote loopback is intrusive in that the other end of the link is not
   forwarding traffic from higher layers out over the link.  This
   document defines objects controlling loopback operation and reading
   the status of the loopback state.

3.4.  Ethernet OAM Protocol Data Units

   An Ethernet OAM protocol data unit is a valid Ethernet frame with a
   destination Media Access Control (MAC) address equal to the reserved
   MAC address for Slow Protocols (See 43B of [802.3ah]), a lengthOrType
   field equal to the reserved type for Slow Protocols, and a Slow
   Protocols subtype equal to that of the subtype reserved for Ethernet
   OAM.

   OAMPDU is used throughout this document as an abbreviation for
   Ethernet OAM protocol data unit.  OAMPDUs are the mechanism by which
   two directly connected Ethernet interfaces exchange OA information.

4.  Relation to the Other MIB Modules

   The definitions presented here are based on Clauses 30 and 57 of
   [802.3ah].  Note that these clauses describe many of these variables
   and their effects on the MAC layer.  In some cases, there is a one-
   to-one relationship between an object in this document and an object
   in the Clause 30 MIB of [802.3ah].  In other cases, the objects of
   this document reflect a more complex entity and are reflected by more
   than one object in the Clause 30 MIB of [802.3ah].

4.1.  Relation to Other MIB Modules

   The objects defined in this document manage OAM functionality
   introduced in [802.3ah]  These objects do not overlap with the
   interfaces MIB [RFC2863], the Ethernet-like interfaces MIB [RFC3635],
   or any other MIB currently used to manage various aspects of an
   Ethernet interface.  The objects defined here are defined for
   Ethernet-like interfaces only and use the same ifIndex as the
   associated Ethernet interface.  Ethernet OAM can be implemented on
   any Ethernet-like interface.

4.2.  Relation to Other EFM MIB Modules

   The Ethernet OAM functionality and MIB Module is independent of the
   other functionality and MIB Modules derived from [802.3ah] for copper
   [802.3ah-copper] and EPON [802.3ah-epon].  Ethernet OAM may be
   implemented (or not) on the new EFM interface types, just as it can
   on any other Ethernet interface.

4.3.  Mapping of IEEE 802.3ah Managed Objects

   This section contains the mapping between managed objects defined in
   [802.3ah] Clause 30, and managed objects defined in this document.

   IEEE 802.3 Managed Object        Corresponding SNMP object

   oOA
    .aOAMID                         IF-MIB ifIndex
    .aOAMAdminState                 dot3OamAdminState
    .aOAMMode                       dot3OamMode
    .aOAMDiscoveryState             dot3OamOperStatus
    .aOAMRemoteMACAddress           dot3OamPeerMacAddress
    .aOAMLocalConfiguration         dot3OamFunctionsSupported
    .aOAMRemoteConfiguration        dot3OamPeerFunctionsSupported,
                                    dot3OamPeerMode
    .aOAMLocalPDUConfiguration      dot3OamMaxOamPduSize
    .aOAMRemotePDUConfiguration     dot3OamPeerMaxOamPduSize
    .aOAMLocalFlagsField            dot3OamOperStatus,
                                    dot3OamEventLogEntry
    .aOAMRemoteFlagsField           dot3OamOperStatus,
                                    dot3OamEventLogEntry
    .aOAMLocalRevision              dot3OamConfigRevision
    .aOAMRemoteRevision             dot3OamPeerConfigRevision
    .aOAMLocalState                 dot3OamLoopbackStatus
    .aOAMRemoteState                dot3OamLoopbackStatus
    .aOAMRemoteVendorOUI            dot3OamPeerVendorOui
    .aOAMRemoteVendorSpecificInfo   dot3OamPeerVendorInfo
    .aOAMUnsupportedCodesTx         dot3OamUnsupportedCodesTx
    .aOAMUnsupportedCodesRx         dot3OamUnsupportedCodesRx
    .aOAMInformationTx              dot3OamInformationTx
    .aOAMInformationRx              dot3OamInformationRx

    .aOAMUniqueEventNotificationTx  dot3OamUniqueEventNotificationTx
    .aOAMUniqueEventNotificationRx  dot3OamUniqueEventNotificationRx
    .aOAMDuplicateEventNotificationTx
                                    dot3OamDuplicateEventNotificationTx
    .aOAMDuplicateEventNotificationRx
                                    dot3OamDuplicateEventNotificationRx
    .aOAMLoopbackControlTx          dot3OamLoopbackControlTx

    .aOAMLoopbackControlRx          dot3OamLoopbackControlRx
    .aOAMVariableRequestTx          dot3OamVariableRequestTx
    .aOAMVariableRequestRx          dot3OamVariableRequestRx
    .aOAMVariableResponseTx         dot3OamVariableResponseTx
    .aOAMVariableResponseRx         dot3OamVariableResponseRx
    .aOAMOrganizationSpecificTx     dot3OamOrgSpecificTx
    .aOAMOrganizationSpecificRx     dot3OamOrgSpecificTx

    .aOAMLocalErrSymPeriodConfig    dot3OamErrSymPeriodWindow,
                                    dot3OamErrSymPeriodThreshold
    .aOAMLocalErrSymPeriodEvent     dot3OamEventLogEntry
    .aOAMLocalErrFrameConfig        dot3OamErrFrameWindow,
                                    dot3OamErrFrameThreshold
    .aOAMLocalErrFrameEvent         dot3OamEventLogEntry
    .aOAMLocalErrFramePeriodConfig  dot3OamErrFramePeriodWindow,
                                    dot3OamErrFramePeriodThreshold
    .aOAMLocalErrFramePeriodEvent   dot3OamEventLogEntry
    .aOAMLocalErrFrameSecsSummaryConfig
                                    dot3OamErrFrameSecsSummaryWindow,
                                    dot3OamErrFrameSecssummaryThreshold
    .aOAMLocalErrFrameSecsSummaryEvent
                                    dot3OamEventLogEntry
    .aOAMRemoteErrSymPeriodEvent    dot3OamEventLogEntry
    .aOAMRemoteErrFrameEvent        dot3OamEventLogEntry
    .aOAMRemoteErrFramePeriodEvent  dot3OamEventLogEntry
    .aOAMRemoteErrFrameSecsSummaryEvent
                                    dot3OamEventLogEntry
    .aFramesLostDueToOAmError       dot3OamFramesLostDueToOam
    .acOAMAdminControl              dot3OamAdminState

   There are no IEEE 802.3ah managed objects that are not reflected in
   this MIB Module in some manner.

5.  MIB Structure

   The Ethernet OAM MIB objects of this memo focus on the OA
   capabilities introduced in [802.3ah].  The MIB objects are
   partitioned into six different MIB groups.

   The dot3OamTable group manages the primary OAM objects of the
   Ethernet interface.  This group controls the state and status of OA
   as well as the mode in which it operates.

   The dot3OamPeerTable maintains the current information on the status
   and configuration of the peer OAM entity on the Ethernet interface.
   Managed information includes the capabilities and function available
   on the peer OAM entity.

   The dot3OamLoopbackTable manages the loopback function introduced in
   [802.3ah].  This table controls enabling and disabling loopback, as
   well as indicating the loopback status of Ethernet OAM on this
   interface.

   The dot3OamStatsTable maintains statistics on the number and type of
   Ethernet OAM frames being transmitted and received on the Ethernet
   interface.

   The dot3OamEventConfigTable defines the objects for managing the
   event notification capability available in Ethernet OAM.  With
   Ethernet OAM, one device may send notifications to its peer devices
   whenever an important event happens on the local device.  This table
   provides management of which events result in notifications via
   Ethernet OAM notifications and/or via SNMP notifications.

   The dot3OamEventLogTable manages the current status of local and
   remote events detected via Ethernet OAM.  This table is updated
   whenever local events are detected by Ethernet OAM or whenever
   Ethernet OAM Event Notifications are received from the peer OA
   entity.

   There are two notifications defined to report Ethernet OAM events
   (one for threshold crossing events, one for non-threshold crossing
   events).  Both notifications are contained within the same
   conformance group.