





Network Working Group                                 G. Roeck, Editor
Request for Comments: 2127                               cisco Systems
Category: Standards Track                                   March 1997


              ISDN Management Information Base using SMIv2

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.

Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in the Internet community.
   In particular, it defines a minimal set of managed objects for SNMP-
   based management of ISDN terminal interfaces.  ISDN interfaces are
   supported on a variety of equipment (for data and voice) including
   terminal adapters, bridges, hosts, and routers.

   This document specifies a MIB module in a manner that is compliant to
   the SNMPv2 SMI.  The set of objects is consistent with the SNMP
   framework and existing SNMP standards.

   This document is a product of the ISDN MIB working group within the
   Internet Engineering Task Force.  Comments are solicited and should
   be addressed to the working group's mailing list at isdn-
   mib@cisco.com and/or the author.

   The current version of this document reflects changes made during the
   last call period and the IESG review.

Table of Contents

   1 The SNMPv2 Network Management Framework ......................    2
   2 Object Definitions ...........................................    2
   3 Overview .....................................................    3
   3.1 Structure of the MIB .......................................    3
   3.1.1 General Description ......................................    3
   3.2 Relationship to the Interfaces MIB .........................    4
   3.2.1 Layering Model ...........................................    4
   3.2.2 ifTestTable ..............................................    8
   3.2.3 ifRcvAddressTable ........................................    8
   3.2.4 ifEntry ..................................................    8



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   3.2.4.1 ifEntry for a Basic Rate hardware interface ............    8
   3.2.4.2 ifEntry for a B channel ................................    9
   3.2.4.3 ifEntry for LAPD (D channel Data Link Layer) ...........   10
   3.2.4.4 ifEntry for a signaling channel ........................   12
   3.3 Relationship to other MIBs .................................   14
   3.3.1 Relationship to the DS1/E1 MIB ...........................   14
   3.3.2 Relationship to the DS0 and DS0Bundle MIBs ...............   14
   3.3.3 Relationship to the Dial Control MIB .....................   14
   3.4 ISDN interface specific information and implementation hints
        ...........................................................   14
   3.4.1 ISDN leased lines ........................................   14
   3.4.2 Hyperchannels ............................................   15
   3.4.3 D channel backup and NFAS trunks .........................   16
   3.4.4 X.25 based packet-mode service in B and D channels .......   16
   3.4.5 SPID handling ............................................   17
   3.4.6 Closed User Groups .......................................   17
   3.4.7 Provision of point-to-point line topology ................   18
   3.4.8 Speech and audio bearer capability information elements ..   18
   3.4.9 Attaching incoming calls to router ports .................   19
   3.4.10 Usage of isdnMibDirectoryGroup and isdnDirectoryTable ...   20
   4 Definitions ..................................................   21
   5 Acknowledgments ..............................................   47
   6 References ...................................................   47
   7 Security Considerations ......................................   49
   8 Author's Address .............................................   49

1.  The SNMPv2 Network Management Framework

   The SNMPv2 Network Management Framework presently consists of three
   major components.  They are:

   o    the SMI, described in RFC 1902 [1] - the mechanisms used for
        describing and naming objects for the purpose of management.

   o    the MIB-II, STD 17, RFC 1213 [2] - the core set of managed
        objects for the Internet suite of protocols.

   o    the protocol, STD 15, RFC 1157 [3] and/or RFC 1905 [4], -
        the protocol for accessing managed objects.

   The Framework permits new objects to be defined for the purpose of
   experimentation and evaluation.

2.  Object Definitions

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  Objects in the MIB are
   defined using the subset of Abstract Syntax Notation One (ASN.1)



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   defined in the SMI.  In particular, each object type is named by an
   OBJECT IDENTIFIER, an administratively assigned name.  The object
   type together with an object instance serves to uniquely identify a
   specific instantiation of the object.  For human convenience, we
   often use a textual string, termed the descriptor, to refer to the
   object type.

3.  Overview

3.1.  Structure of the MIB

   For managing ISDN interfaces, the following information is necessary:

   o    Information for managing physical interfaces. In case of ISDN
        primary rate, this are usually T1 or E1 lines, being managed in
        the DS1/E1 MIB [12].  For Basic Rate lines, physical interfaces
        are managed by this MIB.

   o    Information for managing B channels.

   o    Information for managing signaling channels.

   o    Optionally, information for managing Terminal Endpoints (TE).
        A Terminal Endpoint is a link layer connection to a switch.

   o    Optionally, information for managing a list of directory numbers.

   In order to manage connections over ISDN lines, the management of
   peer information and call history information is required as well.
   This information is defined in the Dial Control MIB [15].

   The purpose for splitting the required information in two MIBs is to
   be able to use parts of this information for non-ISDN interfaces as
   well.  In particular, the Dial Control MIB might also be used for
   other types of interfaces, e.g. modems or X.25 virtual connections.

   Within this document, information has been structured into five
   groups, which are described in the following chapters.

3.1.1.  General Description

   This MIB controls all aspects of ISDN interfaces.  It consists of
   five groups.

   o    The isdnMibBasicRateGroup is used to provide information
        regarding physical Basic Rate interfaces.

   o    The isdnMibBearerGroup is used to control B (bearer) channels.



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        It supports configuration parameters as well as statistical
        information related to B channels.

   o    The isdnMibSignalingGroup is used to control D (delta) channels.
        There are three tables in this group. The isdnSignalingTable and
        isdnSignalingStatsTable support ISDN Network Layer configuration
        and statistics.  The isdnLapdTable supports ISDN Data Link Layer
        (LAPD) configuration and statistics.

   o    The optional isdnMibEndpointGroup can be used to specify
        Terminal Endpoints. It is required only if there are non-ISDN
        endpoints defined for a given D channel, or if additional
        information like Terminal Endpoint Identifier (TEI) values or
        Service Profile IDentifiers (SPID) is required to identify a
        given ISDN user.

   o    The optional isdnMibDirectoryGroup can be used to specify a
        list of directory numbers for each signaling channel.  It is
        required only if the directory numbers to be accepted differ
        from the isdnSignalingCallingAddress as specified in the
        isdnSignalingTable.

3.2.  Relationship to the Interfaces MIB

   This section clarifies the relationship of this MIB to the Interfaces
   MIB [11].  Several areas of correlation are addressed in the
   following subsections.  The implementor is referred to the Interfaces
   MIB document in order to understand the general intent of these
   areas.

3.2.1.  Layering Model

   An ISDN interface usually consists of a D channel and a number of B
   channels, all of which are layered on top of a physical interface.

   Furthermore, there are multiple interface layers for each D channel.
   There are Data Link Layer (LAPD) as well as Network Layer entities.

   This is accomplished in this MIB by creating a logical interface
   (ifEntry) for each of the D channel entities and a logical interface
   (ifEntry) for each of the B channels.  These are then correlated to
   each other and to the physical interface using the ifStack table of
   the Interfaces MIB [11].








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   The basic model, therefore, looks something like this:

       | |
    +--+ +--+
    | D ch. |
    |Layer 3|
    +--+ +--+
       | |        | |            | |    <== interface to upper
    +--+ +--+  +--+ +--+      +--+ +--+     layers, to be provided
    | D ch. |  |   B   |      |   B   |     by ifStack table
    |Layer 2|  |channel| .... |channel|
    +--+ +--+  +--+ +--+      +--+ +--+
       | |        | |            | |    <== attachment to physical
    +--+ +--------+ +------------+ +----+   interfaces, to be provided
    |         physical interface        |   by ifStack table
    |          (S/T, U or T1/E1)        |
    +-----------------------------------+
   Mapping of B/D channels to physical interfaces

   Each D channel can support multiple Terminal Endpoints.  Terminal
   Endpoints can either be one or multiple ISDN signaling channels, or
   channels supporting X.25 based packet mode services.

   To accomplish this, there can be multiple Network Layer entities on
   top of each ISDN Data Link Layer (LAPD) interface.  The detailed
   model therefore looks something like this, including interface types
   as examples:

  +------+  +----+  +----+
  |x25ple|  |isdn|  |isdn|    Terminal Endpoints (X.25 or ISDN)
  +--+---+  +-+--+  +-+--+
     |        |       |
     | +------+       |       |      |   <== Interface to upper layers,
     | | +------------+       |      |       to be provided by ifStack
     | | |                    |      |       table
    ++-+-++                 +-+-+  +-+-+
    |lapd | D channel       |ds0|  |ds0| B channels
    +--+--+ Data Link Layer +-+-+  +-+-+
       |                      |      |
    +--+----------------------+------+--------------------+
    |                 ds1 or isdns/isdnu                  |
    +-----------------------------------------------------+

   Detailed interface mapping

   IfEntries are maintained for each D channel Network Layer entity
   (Terminal Endpoint), for LAPD and for each B channel.




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   The ifType for a Terminal Endpoint can be isdn(63) for ISDN signaling
   channels or x25ple(40) for X.25 based packet mode services.  The
   ifType for D channel Data Link Layer (LAPD) interfaces is lapd(77).
   The ifType for B channels is ds0(81).  The ifType for physical
   interfaces is the matching IANA ifType, usually ds1(18) for Primary
   Rate interfaces or isdns(75)/isdnu(76) for Basic Rate interfaces.

   The ifStackTable is used to map B channels and LAPD interfaces to
   physical interfaces and to map D channel Network Layer interfaces
   (Terminal Endpoints) to LAPD.

   In the example given above, the assignment of index values could for
   example be as follows:

ifIndex ifType      ISDN MIB tables     Description
                    indexed by ifIndex

   1    isdns(75)   isdnBasicRateTable  Basic Rate physical interface
   2    lapd(77)    isdnLapdTable       LAPD interface
   3    x25ple(40)  isdnEndpointTable   X.25 Packet Layer
   4    isdn(63)    isdnSignalingTable  ISDN signaling channel #1
                    isdnEndpointTable
   5    isdn(63)    isdnSignalingTable  ISDN signaling channel #2
                    isdnEndpointTable
   6    ds0(81)     isdnBearerTable     B channel #1
   7    ds0(81)     isdnBearerTable     B channel #2
   8    ppp(23)                         peer entry #1 (see below)
   9    ppp(23)                         peer entry #2 (see below)























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   The corresponding ifStack table entries would then be:

        ifStackTable Entries

        HigherLayer  LowerLayer
        0            3
        0            4
        0            5
        0            8
        0            9
        1            0
        2            1
        3            2
        4            2
        5            2
        6            1
        7            1
        8            6
        9            7

   Mapping of B channels to upper interface layers is usually done using
   the Dial Control MIB. For example, mapping on top of B channels might
   look as follows:

+-------------------------------------------------------+
|               Network Layer Protocol                  |
+------+ +-------+ +-------+ +-------+ +-------+ +------+
       | |       | |       | |       | |       | | <== appears active
     +-+ +-+   +-+ +-+   +-+ +-+   +-+ +-+   +-+ +-+
     | PPP |   | PPP |   | F/R |   | PPP |   | F/R |
     | for |   | for |   | for |   | for |   | for |   ifEntry with
     |Peer1|   |Peer2|   |switch   |Peer3|   |switch   shadow PeerEntry
     |     |   |     |   |  A  |   |     |   |  B  |
     +-+ +-+   +-+ +-+   +-+ +-+   +-+ +-+   +-+ +-+
                 | |                 | |           <== some actually are
    +--+ +--+ +--+ +--+ +--+ +--+ +--+ +--+ +--+ +--+
    |   B   | |   B   | |   B   | |   B   | |   B   |
    |channel| |channel| |channel| |channel| |channel|
    +--+ +--+ +--+ +--+ +--+ +--+ +--+ +--+ +--+ +--+
       | |       | |       | |       | |       | |
+------+ +-------+ +-------+ +-------+ +-------+ +------+
|             Basic/Primary Rate Interface              |
+-------------------------------------------------------+

   Mapping of IP interfaces to Called Peers to B Channels






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   In this model, ifEntries are maintained for each peer.  Each peer is
   required to have an associated ifEntry.  This interface can be of any
   kind, e.g. PPP or LAPB.

   The Dial Control MIB can be used for all types of demand-access
   interfaces, e.g., ISDN, modems or X.25 virtual connections.

3.2.2.  ifTestTable

   The ifTestTable is not supported by this MIB.

3.2.3.  ifRcvAddressTable

   The ifRcvAddressTable is not supported by this MIB.

3.2.4.  ifEntry

3.2.4.1.  ifEntry for a Basic Rate hardware interface

   The ifGeneralGroup is supported for Basic Rate hardware interfaces.

   ifTable           Comments
   ==============    ===========================================
   ifIndex           Each ISDN Basic Rate hardware interface is
                     represented by an ifEntry.

   ifDescr           Textual port description.

   ifType            The IANA value of isdns(75) or isdnu(76),
                     whichever is appropriate.

   ifSpeed           The overall bandwidth of this interface.

   ifPhysAddress     Return an empty string.

   ifAdminStatus     The administrative status of the ISDN interface.

   ifOperStatus      The current operational status of this interface.
                     The operational status is dormant(5) if
                     the interface is in standby mode, i.e. connected
                     to the network, but without call activity.
                     The operational status is down(2) if the hardware
                     has detected that there is no layer 1 connection
                     to the switch.
                     For other values, refer to the Interfaces MIB.

   ifLastChange      Refer to the Interfaces MIB.




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   ifLinkUpDownTrapEnable
                     Refer to the Interfaces MIB.

   ifConnectorPresent
                     Refer to the Interfaces MIB.

   ifHighSpeed       Return zero.

   ifName            Refer to the Interfaces MIB.

3.2.4.2.  ifEntry for a B channel

   The ifEntry for a B channel supports the ifGeneralGroup of the
   Interfaces MIB.

   ifTable           Comments
   ==============    ===========================================
   ifIndex           Each ISDN B channel is represented by an ifEntry.

   ifDescr           Textual port description.

   ifType            The IANA value of ds0(81).

   ifSpeed           The bandwidth of this B channel.
                     Usually, this is the value of 56000 or 64000.

   ifPhysAddress     Return an empty string.

   ifAdminStatus     The administrative status of this interface.

   ifOperStatus      The current operational status of this interface.
                     Note that dormant(5) is explicitly being used
                     as defined in the Interfaces MIB.
                     For other values, refer to the Interfaces MIB.

   ifLastChange      Refer to the Interfaces MIB.

   ifLinkUpDownTrapEnable
                     Refer to the Interfaces MIB.

   ifConnectorPresent
                     Refer to the Interfaces MIB.

   ifHighSpeed       Return zero.

   ifName            Refer to the Interfaces MIB.





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3.2.4.3.  ifEntry for LAPD (D channel Data Link Layer)

   The ifEntry for LAPD (D channel Data Link Layer) supports the
   ifGeneralGroup and the ifPacketGroup of the Interfaces MIB.

   ifTable           Comments
   ==============    ===========================================
   ifIndex           Each ISDN D channel Data Link layer is represented
                     by an ifEntry.

   ifDescr           Textual port description.

   ifType            The IANA value of lapd(77).

   ifSpeed           The bandwidth of this interface. Usually, this is
                     the value of 16000 for basic rate interfaces or
                     64000 for primary rate interfaces.

   ifPhysAddress     Return an empty string.

   ifAdminStatus     The administrative status of this interface.

   ifOperStatus      The current operational status of the ISDN
                     LAPD interface. The operational status is
                     dormant(5) if the interface is in standby mode
                     (see Q.931 [8], Annex F, D channel backup
                     procedures).
                     For other values, refer to the Interfaces MIB.

   ifLastChange      Refer to the Interfaces MIB.

   ifLinkUpDownTrapEnable
                     Refer to the Interfaces MIB.

   ifConnectorPresent
                     Refer to the Interfaces MIB.

   ifHighSpeed       Return zero.

   ifName            Refer to the Interfaces MIB.

   ifMtu             The size of the largest frame which can be
                     sent/received on this interface,
                     specified in octets. Usually, this is the
                     default value of 260 as specified in Q.921
                     [6], chapter 5.9.3.





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   ifInOctets        The total number of octets received on this
                     interface.

   ifInUcastPkts     The number of frames received on this interface
                     whose address is not TEI=127.

   ifInNUcastPkts    Deprecated.  Return the number of frames
                     received on this interface with TEI=127.

   ifInMulticastPkts Return zero.

   ifInBroadcastPkts Return the number of frames received
                     on this interface with TEI=127.

   ifInDiscards      The total number of received frames which have
                     been discarded.
                     The possible reasons are: buffer shortage.

   ifInErrors        The number of inbound frames that contained
                     errors preventing them from being deliverable
                     to LAPD.

   ifInUnknownProtos The number of frames with known TEI, but unknown
                     SAPI (Service Access Point Identifier,
                     see Q.921 [6], chapter 3.3.3).

   ifOutOctets       The total number of octets transmitted on this
                     interface.

   ifOutUcastPkts    The number of frames transmitted on this
                     interface whose address is not TEI=127.

   ifOutNUcastPkts   Deprecated.  Return the number of frames
                     transmitted on this interface with TEI=127.

   ifOutMulticastPkts
                     Return zero.

   ifOutBroadcastPkts
                     Return the number of frames transmitted
                     on this interface with TEI=127.

   ifOutDiscards     The total number of outbound frames which
                     were discarded. Possible reasons are:
                     buffer shortage.

   ifOutErrors       The number of frames which could not be
                     transmitted due to errors.



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   ifOutQlen         Deprecated. Return zero.

   ifSpecific        Deprecated. Return {0 0}.

3.2.4.4.  ifEntry for a signaling channel

   The ifEntry for a signaling channel supports the ifGeneralGroup and
   the ifPacketGroup of the Interfaces MIB.

   ifTable           Comments
   ==============    ===========================================
   ifIndex           Each ISDN signaling channel is represented by
                     an ifEntry.

   ifDescr           Textual port description.

   ifType            The IANA value of isdn(63).

   ifSpeed           The bandwidth of this signaling channel. Usually,
                     this is the same value as for LAPD, i.e. 16000
                     for basic rate interfaces or 64000 for primary rate
                     interfaces.

   ifPhysAddress     The ISDN address assigned to this signaling channel.
                     This is a copy of isdnSignalingCallingAddress.

   ifAdminStatus     The administrative status of the signaling channel.

   ifOperStatus      The current operational status of this signaling
                     channel. The operational status is dormant(5) if
                     the signaling channel is currently not activated.
                     For other values, refer to the Interfaces MIB.

   ifLastChange      Refer to the Interfaces MIB.

   ifLinkUpDownTrapEnable
                     Refer to the Interfaces MIB.

   ifConnectorPresent
                     Refer to the Interfaces MIB.

   ifHighSpeed       Return zero.

   ifName            Refer to the Interfaces MIB.







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   ifMtu             The size of the largest frame which can be
                     sent/received on this signaling channel,
                     specified in octets. Usually, this is the
                     default value of 260 as specified in Q.921
                     [6], chapter 5.9.3.

   ifInOctets        The total number of octets received on this
                     signaling channel.

   ifInUcastPkts     The number of frames received which are targeted
                     to this channel.

   ifInNUcastPkts    Deprecated.  Return the number of frames
                     received on this signaling channel with TEI=127.

   ifInMulticastPkts Return zero.

   ifInBroadcastPkts Return the number of frames received
                     on this signaling channel with TEI=127.

   ifInDiscards      The total number of received frames which have been
                     discarded.
                     The possible reasons are: buffer shortage.

   ifInErrors        The number of inbound frames that contained
                     errors preventing them from being deliverable
                     to the signaling channel.

   ifInUnknownProtos Return zero.

   ifOutOctets       The total number of octets transmitted on this
                     signaling channel.

   ifOutUcastPkts    The number of frames transmitted on this
                     signaling channel whose address is not TEI=127.

   ifOutNUcastPkts   Deprecated.  Return the number of frames
                     transmitted on this signaling channel with TEI=127.

   ifOutMulticastPkts
                     Return zero.

   ifOutBroadcastPkts
                     Return the number of frames transmitted
                     on this signaling channel with TEI=127.






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   ifOutDiscards     The total number of outbound frames which
                     were discarded. Possible reasons are:
                     buffer shortage.

   ifOutErrors       The number of frames which could not be
                     transmitted due to errors.

   ifOutQlen         Deprecated. Return zero.

   ifSpecific        Deprecated. Return {0 0}.

3.3.  Relationship to other MIBs

3.3.1.  Relationship to the DS1/E1 MIB

   Implementation of the DS1/E1 MIB [12] is not required for supporting
   this MIB. It is however recommended to implement the DS1/E1 MIB on
   entities supporting Primary Rate interfaces.

3.3.2.  Relationship to the DS0 and DS0Bundle MIBs

   Implementation of the DS0 MIB [13] is optional.

   Implementation of the DS0Bundle MIB [13] may be required only if
   hyperchannels are to be supported, depending on the multiplexing
   scheme used in a given implementation. See chapter 3.4.2 for details
   on how to implement hyperchannels.

3.3.3.  Relationship to the Dial Control MIB

   Implementation of the Dial Control MIB [15] is required.

3.4.  ISDN interface specific information and implementation hints

3.4.1.  ISDN leased lines

   ISDN leased lines can be specified on a per-B-channel basis.  To do
   so, the value of isdnBearerChannelType has to be set to leased(2).
   There is no signaling protocol support for leased line B channels,
   since there is no signaling protocol action for these kinds of
   interfaces.










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   If there is no signaling support available for an ISDN interface,
   this must be specified in the appropriate interface specific table.
   For Basic Rate interfaces, isdnBasicRateSignalMode of
   isdnBasicRateTable must be set to inactive(2).  For Primary Rate
   interfaces, dsx1SignalMode of dsx1ConfigTable in DS1/E1 MIB [12] must
   be set to none(1).  There are no isdnLapdTable or isdnSignalingTable
   entries for such interfaces.

   Depending on the leased line type and the service provider, the D
   channel can be used for data transfer.  If this is the case the D
   channel interface type is ds0(81) instead of lapd(77) and its usage
   is identical to B channel usage if there is no signaling channel
   available.

   For a Primary Rate interface which is entirely used as a leased line,
   there is no ISDN specific information available or required.  Such
   leased lines can entirely be handled by the DS1/E1 MIB.

3.4.2.  Hyperchannels

   The active switch protocol defines if hyperchannels are supported,
   and the actual support is implementation dependent.  Hyperchannel
   connections will be requested by the interface user at call setup
   time, e.g. by the peer connection handling procedures.

   In the ISDN MIB, the isdnBearerMultirate object of isdnBearerTable
   can be used to check if hyperchannels are being used for an active
   call.

   If hyperchannels are being used, multiplexing between the
   encapsulation layer and the B channels is required, since there is
   one encapsulation layer interface connected to several B channel
   interfaces.  This can be accomplished in two ways.

   o    The DS0Bundle MIB [13] can be used to provide the multiplexing.
        See the DS0Bundle MIB document for details.

   o    The ifStackTable can be used to provide the multiplexing.  In
        this case, there are several ifStackTable entries with the same
        value of HigherLayer, and different values of LowerLayer.

   It is up to the implementor to decide which multiplexing scheme to
   use.

   Each hyperchannel call is treated as one call in the
   isdnSignalingStatsTable, independent of the number of B channels
   involved.




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   For a hyperchannel call, all objects in the isdnBearerTable entries
   related to this call (i.e., all isdnBearerTable entries associated to
   B channels used by the hyperchannel) have identical values.  The
   related objects in the isdnBearerTable are:


       isdnBearerPeerAddress
       isdnBearerPeerSubAddress
       isdnBearerCallOrigin
       isdnBearerInfoType
       isdnBearerMultirate
       isdnBearerCallSetupTime
       isdnBearerCallConnectTime
       isdnBearerChargedUnits

3.4.3.  D channel backup and NFAS trunks

   D channel backup is defined in Q.931 [8], Annex F.  It describes Non-
   Associated signaling and its use and functionality is basically
   identical to Non Facility Associated Signaling (NFAS) trunks.

   Non Facility Accociated Signaling (NFAS) basically means that a D
   channel on a PRI interface is used to manage calls on other PRI
   trunks.  This is required in North America for H11 channels, since
   all 24 time slots are being used for B channels.

   According to Q.931, Annex F, the D channel backup feature can be
   provided on a subscription basis and is network dependent.  The D
   channel backup procedure is described in detail in Q.931.

   For D channel backup, the controlling isdnSignalingTable entry is
   layered on top of all attached LAPD interfaces.  This layering is
   done using the ifStack table.  There is only one active LAPD
   interface, however.  Inactive LAPD interfaces have an ifOperStatus of
   dormant(5).

   NFAS trunks are also handled using the ifStack table. In this case, a
   signaling channel is layered on top of a LAPD interface as well as on
   top of all physical interfaces which are controlled by the signaling
   channel, but do not supply a D channel.

3.4.4.  X.25 based packet-mode service in B and D channels

   X.25 based packet mode service over B channels can be handled using
   the Dial Control MIB by creating an appropriate peer entry.  The peer
   entry ifType can then be x25(5), thus providing access to X.25
   service.




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   X.25 based packet mode service over D channels can be handled by
   creating an ifEndpointTable entry with an isdnEndpointIfType of
   x25ple(40).  The upper protocol layers can then be attached to this
   interface using the ifStack table.

3.4.5.  SPID handling

   Service Profile IDentifiers (SPIDs) are defined for BRI interfaces
   only, and being used in North America.  SPIDs are required for DMS-
   100, NI-1 and NI-2, and are optional for 5ESS.  A switch can define
   up to 8 SPIDs per BRI.

   Each Terminal Endpoint has a SPID assigned.  It is normally built
   from the party number (calling address for outgoing calls) with a
   number of digits prepended and appended.  Since each network appears
   to be different, both the calling address and the SPID have to be
   stored.

   The SPID identifies the particular services that have been
   provisioned for a terminal. If there are two B channels on a BRI,
   there can be two SPIDs, one for each of the two B channels.  There
   can also be a single SPID, providing access to both B channels.

   The SPID gets registered with the switch after link establishment.
   There is one data link for each SPID. As part of terminal
   registration, an EID (Endpoint IDentifier) is defined by the switch.
   On incoming calls, the switch may provide the EID, a called party
   number, or both, depending on the ISDN code implemented in the
   switch.

   The EID has two bytes: USID (User Service IDentifier) and TID
   (Terminal IDentifier). These are later used by some of the software
   versions running on the switch side (e.g. compliant with NI-1, 5ESS
   custom) to broadcast SETUP messages with these included, so the
   correct endpoint would accept the call. Other switch software
   versions identify the endpoint with the Called Party Number.

   In the ISDN MIB, the SPID can be entered using the isdnEndpointSpid
   object of isdnEndpointTable.  The isdnSignalingCallingAddress,
   already being used to specify the calling number, cannot be used to
   record the SPID since the values of the SPID and the Calling Address
   may differ and both may be required to be present.

3.4.6.  Closed User Groups

   Closed User Groups (CUG), as defined in I.255.1 [14], are supported
   for circuit mode calls by ETSI (ETS 300 138) and 1TR6.  In these
   networks, an ISDN address can have one or more Closed User Groups



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   assigned.  If there is more than one Closed User Group assigned to a
   given address, one of those is the preferred Closed User Group.  For
   such addresses, only calls from assigned Closed User Groups are
   accepted by the network.

   Thus, Closed User Groups are a parameter for peer entries and are
   defined in the Dial Control MIB. A peer entry attached to a Closed
   User Group has to point to an ISDN interface which is attached to the
   Closed User Group in question.

3.4.7.  Provision of point-to-point line topology

   In the ISDN standards, there are two different meanings for the term
   "point-to-point".

   In ISDN standards, the term point-to-point are usually used for data
   link connections, i.e. layer 2 connections, where each layer 2
   connection from the TE to the network is a single point-to-point
   connection.  Multiple connections of this kind may exist on one
   physical (layer 1) connection, however, and in case of Basic Rate
   interfaces there may be several TE's connected to one physical line
   to the network.

   The second meaning of "point-to-point" refers to the line topology,
   i.e.  to layer 1 connections.  For Primary Rate interfaces, the line
   topology is always point-to-point.  For Basic Rate interfaces, layer
   1 point-to- point connections do exist in several countries, usually
   being used for connecting PBX systems to the network.

   The second meaning (layer 1 connections) is what will be referred to
   as "point-to-point" connection throughout this document.

   For Basic Rate interfaces, the isdnBasicRateTable object
   isdnBasicRateLineTopology can be used to select the line topology.

3.4.8.  Speech and audio bearer capability information elements

   The objects speech(2), audio31(6) and audio7(7), as being used in
   isdnBearerInfoType, refer to the Speech, 3.1 kHz Audio and old 7 kHz
   Audio (now Multi-use) bearer capabilities for ISDN, as defined in
   Q.931 [8], chapter 4.5.5, octet 3 of bearer capability information
   element.

   These capabilities are signaling artifices that allow networks to do
   certain things with the call.  It is up to the network to decide what
   to do.





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   The Speech Bearer Capability means that speech is being carried over
   the channel, as in two people talking.  This would be POTS-type
   speech.  The network may compress this, encrypt it or whatever it
   wants with it as long as it delivers POTS quality speech to the other
   end.  In other words, a modem is not guaranteed to work over this
   connection.

   The 3.1 kHz Audio capability indicates that the network carries the
   3.1 kHz bandwidth across the network.  This would (theoretically)
   allow modem signals to be carried across the network.  In the US, the
   network automatically enters a capability of 3.1 kHz Audio on calls
   coming into the ISDN from a POTS network.  This capability restricts
   the network from interfering with the data channel in a way that
   would corrupt the 3.1 kHz VoiceBand data.

   7 kHz Audio was meant to signal the use of a higher quality audio
   connection (e.g., music from radio).  It was changed to Multi-Use
   capability to allow it to be used for video-conferencing with fall
   back to audio.

   In some cases, the Speech or 3.1 kHz Bearer Capability provides a 56
   kbit/s data path through the network.  Therefore, some people are
   setting up calls with the Speech or 3.1 kHz BC and transmitting 56
   kbit/s data over the connection.  This is usually to take advantage
   of favorable tariffs for Speech as opposed to Data.

   On the incoming side, the equipment is usually configured to ignore
   the Bearer Capability and either answer all Speech calls as 56 kbit/s
   data or to use one Directory Number for real speech and another for
   data.

3.4.9.  Attaching incoming calls to router ports

   In ISDN, there are several ways to identify an incoming call and to
   attach a router port to this call.

   o    The call can be identified and attached to a router port using
        the ISDN Calling Address, that is, the peer ISDN address.  Since
        the peer address is defined in a Dial Control MIB configuration
        entry for this peer, this would be the most natural way to
        attach an incoming call to a router port.

        In this configuration, only a single isdnSignalingTable entry is
        required for each physical ISDN interface.  Unfortunately, the
        ISDN Calling Address is not available in all countries and/or
        switch protocols.  Therefore, other means for attaching incoming
        calls to router ports must be provided.




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   o    The call can also be identified and attached to a router port
        using the ISDN Called Address.  In this case, a distinct ISDN
        address or subaddress must be specified for each of the router
        ports.  This can be accomplished in the ISDN MIB by creating a
        isdnSignalingTable entry for each of the router ports, and by
        connecting Dial Control MIB peer entries to the thereby created
        interface using the dialCtlPeerCfgLowerIf object of
        dialCtlPeerCfgTable.

        If this type of router port identification is used in an
        implementation, it is up to the implementor to decide if there
        should be distinct TEI values assigned for each of the
        isdnSignalingTable entries.  For this reason, the
        isdnEndpointTable permits specifying the same TEI value in
        multiple entries.  It is recommended to use dynamic TEI
        assignment whenever possible.

        The implementor should be aware that this type of configuration
        requires a lot of configuration work for the customer, since an
        entry in isdnSignalingTable must be created for each of the
        router ports.

   o    Incoming calls can also be identified and attached to router
        ports using a higher layer functionality, such as PPP
        authentication.  Defining this functionality is outside the
        scope of this document.

3.4.10.  Usage of isdnMibDirectoryGroup and isdnDirectoryTable

   In some switch protocol or PBX implementations, the Called Number
   Information Element on incoming calls can differ from the Calling
   Number on outgoing calls.  Sometimes, the Called Number can be
   different for incoming Local Calls, Long Distance Calls and
   International Calls.  For Hunt Groups, the Called Number can be any
   of the numbers in the Hunt Group.

   The isdnDirectoryTable can be used to specify all these numbers.

   Entries in the isdnDirectoryTable are always connected to specific
   isdnSignalingTable entries.  No ifEntry is created for
   isdnDirectoryTable entries.  Therefore, the isdnDirectoryTable can
   not be used to attach incoming calls to router ports.  For router
   port identification, isdnSignalingTable entries should be created
   instead.







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4.  Definitions

ISDN-MIB DEFINITIONS ::= BEGIN

IMPORTS
        MODULE-IDENTITY,
        NOTIFICATION-TYPE,
        OBJECT-TYPE,
        Counter32,
        Gauge32,
        Integer32
                FROM SNMPv2-SMI
        DisplayString,
        TruthValue,
        TimeStamp,
        RowStatus,
        TestAndIncr,
        TEXTUAL-CONVENTION
                 FROM SNMPv2-TC
        MODULE-COMPLIANCE,
        OBJECT-GROUP,
        NOTIFICATION-GROUP
                FROM SNMPv2-CONF
        ifIndex,
        InterfaceIndex
                FROM IF-MIB
        IANAifType
                FROM IANAifType-MIB
        transmission
                FROM RFC1213-MIB;

isdnMib MODULE-IDENTITY
        LAST-UPDATED    "9609231642Z" -- Sep 23, 1996
        ORGANIZATION    "IETF ISDN MIB Working Group"
        CONTACT-INFO
            "        Guenter Roeck
             Postal: cisco Systems
                     170 West Tasman Drive
                     San Jose, CA 95134
                     U.S.A.
             Phone:  +1 408 527 3143
             E-mail: groeck@cisco.com"
        DESCRIPTION
            "The MIB module to describe the
             management of ISDN interfaces."
        ::= { transmission 20 }

-- The ISDN hardware interface (BRI or PRI) is represented



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-- by a media specific ifEntry.
--
-- For basic rate lines, the media specifics for the physical interface
-- is defined in the physical interface group of the ISDN MIB.
-- The ifType for physical basic rate interfaces is isdns(75)
-- or isdnu(76), whichever is appropriate.
--
-- For primary rate, the media specifics are defined in the Trunk
-- MIB and the ifType has a value of ds1(18).

-- Each signaling channel is represented by an entry
-- in the isdnSignalingTable.
-- The signaling channel has an ifType value of isdn(63).
-- Each B channel is also represented as an entry
-- in the ifTable. The B channels have an ifType value
-- of ds0(81).
-- This model is used while defining objects and tables
-- for management.
-- The ISDN MIB allows sub-layers. For example, the data transfer
-- over a B channel may take place with PPP encapsulation. While the
-- ISDN MIB describes the D and B channels, a media specific MIB
-- for PPP can be used on a layered basis. This is as per
-- the interfaces MIB.

-- Textual conventions

IsdnSignalingProtocol ::= TEXTUAL-CONVENTION
        STATUS      current
        DESCRIPTION
            "This data type is used as the syntax of the
             isdnSignalingProtocol object in the
             definition of ISDN-MIB's isdnSignalingTable.

             The definition of this textual convention with the
             addition of newly assigned values is published
             periodically by the IANA, in either the Assigned
             Numbers RFC, or some derivative of it specific to
             Internet Network Management number assignments.  (The
             latest arrangements can be obtained by contacting the
             IANA.)

             Requests for new values should be made to IANA via
             email (iana@iana.org)."
        SYNTAX      INTEGER {
             other(1),          -- none of the following
             dss1(2),           -- ITU DSS1 (formerly CCITT) Q.931
             etsi(3),           -- Europe / ETSI ETS300-102
                                -- plus supplementary services



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                                -- (ETSI 300-xxx)
                                -- note that NET3, NET5 define
                                -- test procedures for ETS300-102
                                -- and have been replaced by
                                -- I-CTR 3 and I-CTR 4.
             dass2(4),          -- U.K.   / DASS2 (PRI)
             ess4(5),           -- U.S.A. / AT&T 4ESS
             ess5(6),           -- U.S.A. / AT&T 5ESS
             dms100(7),         -- U.S.A. / Northern Telecom DMS100
             dms250(8),         -- U.S.A. / Northern Telecom DMS250
             ni1(9),            -- U.S.A. / National ISDN 1 (BRI)
             ni2(10),           -- U.S.A. / National ISDN 2 (BRI, PRI)
             ni3(11),           -- U.S.A. / next one
             vn2(12),           -- France / VN2
             vn3(13),           -- France / VN3
             vn4(14),           -- France / VN4 (ETSI with changes)
             vn6(15),           -- France / VN6 (ETSI with changes)
                                -- delta document CSE P 10-21 A
                                -- test document  CSE P 10-20 A
             kdd(16),           -- Japan  / KDD
             ins64(17),         -- Japan  / NTT INS64
             ins1500(18),       -- Japan  / NTT INS1500
             itr6(19),          -- Germany/ 1TR6 (BRI, PRI)
             cornet(20),        -- Germany/ Siemens HiCom CORNET
             ts013(21),         -- Australia / TS013
                                -- (formerly TPH 1962, BRI)
             ts014(22),         -- Australia / TS014
                                -- (formerly TPH 1856, PRI)
             qsig(23),          -- Q.SIG
             swissnet2(24),     -- SwissNet-2
             swissnet3(25)      -- SwissNet-3
        }

-- Isdn Mib objects definitions

isdnMibObjects OBJECT IDENTIFIER ::= { isdnMib 1 }

-- ISDN physical interface group

-- This group describes physical basic rate interfaces.

isdnBasicRateGroup      OBJECT IDENTIFIER ::= { isdnMibObjects 1 }

isdnBasicRateTable OBJECT-TYPE
        SYNTAX      SEQUENCE OF IsdnBasicRateEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION



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            "Table containing configuration and operational
             parameters for all physical Basic Rate
             interfaces on this managed device."
        ::= { isdnBasicRateGroup 1 }

isdnBasicRateEntry OBJECT-TYPE
        SYNTAX      IsdnBasicRateEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "An entry in the ISDN Basic Rate Table."
        INDEX { ifIndex }
        ::= { isdnBasicRateTable 1 }

IsdnBasicRateEntry ::= SEQUENCE {
            isdnBasicRateIfType         INTEGER,
            isdnBasicRateLineTopology   INTEGER,
            isdnBasicRateIfMode         INTEGER,
            isdnBasicRateSignalMode     INTEGER
        }

isdnBasicRateIfType OBJECT-TYPE
        SYNTAX      INTEGER {
            isdns(75),
            isdnu(76)
        }
        MAX-ACCESS  read-write
        STATUS      current
        DESCRIPTION
            "The physical interface type. For 'S/T' interfaces,
             also called 'Four-wire Basic Access Interface',
             the value of this object is isdns(75).
             For 'U' interfaces, also called 'Two-wire Basic
             Access Interface', the value of this object is
             isdnu(76)."
        ::= { isdnBasicRateEntry 1 }

isdnBasicRateLineTopology OBJECT-TYPE
        SYNTAX      INTEGER {
            pointToPoint(1),
            pointToMultipoint(2)
        }
        MAX-ACCESS  read-write
        STATUS      current
        DESCRIPTION
            "The line topology to be used for this interface.
             Note that setting isdnBasicRateIfType to isdns(75)
             does not necessarily mean a line topology of



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             point-to-multipoint."
        ::= { isdnBasicRateEntry 2 }

isdnBasicRateIfMode OBJECT-TYPE
        SYNTAX      INTEGER {
            te(1),
            nt(2)
        }
        MAX-ACCESS  read-write
        STATUS      current
        DESCRIPTION
            "The physical interface mode. For TE mode, the value
             of this object is te(1). For NT mode, the value
             of this object is nt(2)."
        ::= { isdnBasicRateEntry 3 }

isdnBasicRateSignalMode OBJECT-TYPE
        SYNTAX      INTEGER {
            active(1),
            inactive(2)
        }
        MAX-ACCESS  read-write
        STATUS      current
        DESCRIPTION
            "The signaling channel operational mode for this interface.
             If active(1) there is a signaling channel on this
             interface. If inactive(2) a signaling channel is
             not available."
        ::= { isdnBasicRateEntry 4 }

-- The B channel (bearer channel) group

-- Note that disconnects can explicitely be handled using the
-- ifStack table. If a connection is to be disconnected,
-- the according ifStack entry has to be removed.
-- More specifically, the ifStackTable entry which binds the high-layer
-- ifTable entry (and related dialCtlNbrCfgTable entry) to the
-- B channel ifTable entry (and related isdnBearerTable entry)
-- during an active call has to be removed.

isdnBearerGroup OBJECT IDENTIFIER ::= { isdnMibObjects 2 }

isdnBearerTable OBJECT-TYPE
        SYNTAX      SEQUENCE OF IsdnBearerEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "This table defines port specific operational, statistics



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             and active call data for ISDN B channels. Each entry
             in this table describes one B (bearer) channel."
        ::= { isdnBearerGroup 1 }

isdnBearerEntry OBJECT-TYPE
        SYNTAX      IsdnBearerEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "Operational and statistics information relating to
             one port. A port is a single B channel."
        INDEX { ifIndex }
        ::= { isdnBearerTable 1 }

IsdnBearerEntry ::=
        SEQUENCE {
            isdnBearerChannelType           INTEGER,
            isdnBearerOperStatus            INTEGER,
            isdnBearerChannelNumber         INTEGER,
            isdnBearerPeerAddress           DisplayString,
            isdnBearerPeerSubAddress        DisplayString,
            isdnBearerCallOrigin            INTEGER,
            isdnBearerInfoType              INTEGER,
            isdnBearerMultirate             TruthValue,
            isdnBearerCallSetupTime         TimeStamp,
            isdnBearerCallConnectTime       TimeStamp,
            isdnBearerChargedUnits          Gauge32
        }

isdnBearerChannelType           OBJECT-TYPE
        SYNTAX INTEGER {
            dialup(1),
            leased(2)
        }
        MAX-ACCESS  read-write
        STATUS      current
        DESCRIPTION
            "The B channel type. If the B channel is connected
             to a dialup line, this object has a value of
             dialup(1). In this case, it is controlled by
             an associated signaling channel. If the B channel
             is connected to a leased line, this object has
             a value of leased(2). For leased line B channels, there
             is no signaling channel control available."
        ::= { isdnBearerEntry 1 }

isdnBearerOperStatus            OBJECT-TYPE
        SYNTAX INTEGER {



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            idle(1),
            connecting(2),
            connected(3),
            active(4)
        }
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The current call control state for this port.
             idle(1):       The B channel is idle.
                            No call or call attempt is going on.
             connecting(2): A connection attempt (outgoing call)
                            is being made on this interface.
             connected(3):  An incoming call is in the process
                            of validation.
             active(4):     A call is active on this interface."
        ::= { isdnBearerEntry 2 }

isdnBearerChannelNumber         OBJECT-TYPE
        SYNTAX INTEGER (1..30)
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The identifier being used by a signaling protocol
             to identify this B channel, also referred to as
             B channel number. If the Agent also supports the DS0 MIB,
             the values of isdnBearerChannelNumber and dsx0Ds0Number
             must be identical for a given B channel."
        ::= { isdnBearerEntry 3 }

isdnBearerPeerAddress           OBJECT-TYPE
        SYNTAX   DisplayString
        MAX-ACCESS   read-only
        STATUS   current
        DESCRIPTION
            "The ISDN address the current or last call is or was
             connected to.

             In some cases, the format of this information can not
             be predicted, since it largely depends on the type
             of switch or PBX the device is connected to. Therefore,
             the detailed format of this information is not
             specified and is implementation dependent.

             If possible, the agent should supply this information
             using the E.164 format. In this case, the number must
             start with '+'. Otherwise, IA5 number digits must be used.




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             If the peer ISDN address is not available,
             this object has a length of zero."
        REFERENCE
            "ITU-T E.164, Q.931 chapter 4.5.10"
        ::= { isdnBearerEntry 4 }

isdnBearerPeerSubAddress        OBJECT-TYPE
        SYNTAX   DisplayString
        MAX-ACCESS   read-only
        STATUS   current
        DESCRIPTION
            "The ISDN subaddress the current or last call is or was
             connected to.

             The subaddress is an user supplied string of up to 20
             IA5 characters and is transmitted transparently through
             the network.

             If the peer subaddress is not available, this object
             has a length of zero."
        REFERENCE
             "ITU-T I.330, Q.931 chapter 4.5.11"
        ::= { isdnBearerEntry 5 }

isdnBearerCallOrigin            OBJECT-TYPE
          SYNTAX   INTEGER {
            unknown(1),
            originate(2),
            answer(3),
            callback(4)
        }
        MAX-ACCESS   read-only
        STATUS   current
        DESCRIPTION
            "The call origin for the current or last call. If since
             system startup there was no call on this interface,
             this object has a value of unknown(1)."
        ::= { isdnBearerEntry 6 }

isdnBearerInfoType              OBJECT-TYPE
        SYNTAX      INTEGER {
            unknown(1),
            speech(2),
            unrestrictedDigital(3),       -- as defined in Q.931
            unrestrictedDigital56(4),     -- with 56k rate adaption
            restrictedDigital(5),
            audio31(6),                   -- 3.1 kHz audio
            audio7(7),                    -- 7 kHz audio



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            video(8),
            packetSwitched(9)
        }
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The Information Transfer Capability for the current
             or last call.

             speech(2) refers to a non-data connection, whereas
             audio31(6) and audio7(7) refer to data mode connections.

             Note that Q.931, chapter 4.5.5, originally defined
             audio7(7) as '7 kHz audio' and now defines it as
             'Unrestricted digital information with tones/
             announcements'.

             If since system startup there has been no call on this
             interface, this object has a value of unknown(1)."
        REFERENCE
            "Q.931 [8], chapter 4.5.5, octet 3 of bearer capability
             information element, combined with the User Rate
             (as defined in octets 5 and 5a to 5d), if rate adaption
             is being used."
        ::= { isdnBearerEntry 7 }

isdnBearerMultirate             OBJECT-TYPE
        SYNTAX      TruthValue
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "This flag indicates if the current or last call used
             multirate. The actual information transfer rate,
             in detail specified in octet 4.1 (rate multiplier),
             is the sum of all B channel ifSpeed values for
             the hyperchannel.

             If since system startup there was no call on this
             interface, this object has a value of false(2)."
        REFERENCE
            "Q.931 [8], chapter 4.5.5."
        ::= { isdnBearerEntry 8 }

isdnBearerCallSetupTime         OBJECT-TYPE
        SYNTAX      TimeStamp
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION



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            "The value of sysUpTime when the ISDN setup message for
             the current or last call was sent or received. If since
             system startup there has been no call on this interface,
             this object has a value of zero."
        ::= { isdnBearerEntry 9 }

isdnBearerCallConnectTime       OBJECT-TYPE
        SYNTAX      TimeStamp
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The value of sysUpTime when the ISDN connect message for
             the current or last call was sent or received. If since
             system startup there has been no call on this interface,
             this object has a value of zero."
        ::= { isdnBearerEntry 10 }

isdnBearerChargedUnits          OBJECT-TYPE
        SYNTAX      Gauge32
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The number of charged units for the current or last
             connection. For incoming calls or if charging information
             is not supplied by the switch, the value of this object
             is zero."
        ::= { isdnBearerEntry 11 }

-- ISDN signaling group

isdnSignalingGroup OBJECT IDENTIFIER ::= { isdnMibObjects 3 }

-- signaling channel configuration table
-- There is one entry in this table for each Terminal Endpoint
-- (link layer connection to the switch).
-- Usually, there is one endpoint per D channel. In some
-- cases, however, there can be multiple endpoints.
-- Thus, entries in this table can be created and deleted.
-- This also means the creation of an associated ifEntry.
--
-- D channel backup and NFAS trunks are handled using the
-- ifStack table.
-- In case of D channel backup, there are multiple
-- Data Link Layer (LAPD) interfaces. Only one interface is
-- active; all others are dormant(5).
-- In case of NFAS trunks, one lower interface is the
-- LAPD interface, while the other lower interfaces are physical
-- interfaces.



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-- If directory number and calling address differ from each other
-- or multiple directory numbers are being used,
-- the isdnDirectoryTable has to be used to enter such
-- directory numbers.

isdnSignalingGetIndex OBJECT-TYPE
        SYNTAX      TestAndIncr
        MAX-ACCESS  read-write
        STATUS      current
        DESCRIPTION
            "The recommended procedure for selecting a new index for
             isdnSignalingTable row creation is to GET the value of
             this object, and then to SET the object with the same
             value. If the SET operation succeeds, the manager can use
             this value as an index to create a new row in this table."
        REFERENCE
            "RFC1903, TestAndIncr textual convention."
        ::= { isdnSignalingGroup 1 }

isdnSignalingTable OBJECT-TYPE
        SYNTAX      SEQUENCE OF IsdnSignalingEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "ISDN signaling table containing configuration and
             operational parameters for all ISDN signaling
             channels on this managed device."
        ::= { isdnSignalingGroup 2 }

isdnSignalingEntry OBJECT-TYPE
        SYNTAX      IsdnSignalingEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "An entry in the ISDN Signaling Table. To create a new
             entry, only isdnSignalingProtocol needs to be specified
             before isdnSignalingStatus can become active(1)."
        INDEX { isdnSignalingIndex }
        ::= { isdnSignalingTable 1 }

IsdnSignalingEntry ::= SEQUENCE {
            isdnSignalingIndex          INTEGER,
            isdnSignalingIfIndex        InterfaceIndex,
            isdnSignalingProtocol       IsdnSignalingProtocol,
            isdnSignalingCallingAddress DisplayString,
            isdnSignalingSubAddress     DisplayString,
            isdnSignalingBchannelCount  Integer32,
            isdnSignalingInfoTrapEnable INTEGER,



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            isdnSignalingStatus         RowStatus
        }

isdnSignalingIndex OBJECT-TYPE
        SYNTAX      INTEGER (1..2147483647)
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "The index value which uniquely identifies an entry
             in the isdnSignalingTable."
        ::= { isdnSignalingEntry 1 }

isdnSignalingIfIndex OBJECT-TYPE
        SYNTAX      InterfaceIndex
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The ifIndex value of the interface associated with this
             signaling channel."
        ::= { isdnSignalingEntry 2 }

isdnSignalingProtocol OBJECT-TYPE
        SYNTAX      IsdnSignalingProtocol
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "The particular protocol type supported by the
             switch providing access to the ISDN network
             to which this signaling channel is connected."
        ::= { isdnSignalingEntry 3 }

isdnSignalingCallingAddress OBJECT-TYPE
        SYNTAX      DisplayString
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "The ISDN Address to be assigned to this signaling
             channel. More specifically, this is the 'Calling Address
             information element' as being passed to the switch
             in outgoing call setup messages.

             It can be an EAZ (1TR6), a calling number (DSS1, ETSI)
             or any other number necessary to identify a signaling
             interface. If there is no such number defined or required,
             this is a zero length string. It is represented in
             DisplayString form.

             Incoming calls can also be identified by this number.



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             If the Directory Number, i.e. the Called Number in
             incoming calls, is different to this number, the
             isdnDirectoryTable has to be used to specify all
             possible Directory Numbers.

             The format of this information largely depends on the type
             of switch or PBX the device is connected to. Therefore,
             the detailed format of this information is not
             specified and is implementation dependent.

             If possible, the agent should implement this information
             using the E.164 number format. In this case, the number
             must start with '+'. Otherwise, IA5 number digits must
             be used."
        REFERENCE
            "ITU-T E.164, Q.931 chapter 4.5.10"
        DEFVAL { "" }
        ::= { isdnSignalingEntry 4 }

isdnSignalingSubAddress OBJECT-TYPE
        SYNTAX      DisplayString
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "Supplementary information to the ISDN address assigned
             to this signaling channel. Usually, this is the
             subaddress as defined in Q.931.
             If there is no such number defined or required, this is
             a zero length string.
             The subaddress is used for incoming calls as well as
             for outgoing calls.
             The subaddress is an user supplied string of up to 20
             IA5 characters and is transmitted transparently through
             the network."
        REFERENCE
            "ITU-T I.330, Q.931 chapter 4.5.11"
        DEFVAL { "" }
        ::= { isdnSignalingEntry 5 }

isdnSignalingBchannelCount OBJECT-TYPE
        SYNTAX      Integer32 (1..65535)
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "The total number of B channels (bearer channels)
             managed by this signaling channel. The default value
             of this object depends on the physical interface type
             and is either 2 for Basic Rate interfaces or



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             24 (30) for Primary Rate interfaces."
        ::= { isdnSignalingEntry 6 }

isdnSignalingInfoTrapEnable    OBJECT-TYPE
        SYNTAX      INTEGER {
            enabled(1),
            disabled(2)
        }
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "Indicates whether isdnMibCallInformation traps
             should be generated for calls on this signaling
             channel."
        DEFVAL      { disabled }
        ::= { isdnSignalingEntry 7 }

isdnSignalingStatus OBJECT-TYPE
        SYNTAX      RowStatus
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "This object is used to create and delete rows in the
             isdnSignalingTable."
        ::= { isdnSignalingEntry 8 }

-- Signaling channel statistics table
-- There is one entry for each signaling connection
-- in this table.
-- Note that the ifEntry also has some statistics information.

isdnSignalingStatsTable OBJECT-TYPE
        SYNTAX      SEQUENCE OF IsdnSignalingStatsEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "ISDN signaling table containing statistics
             information for all ISDN signaling channels
             on this managed device.
             Only statistical information which is not already being
             counted in the ifTable is being defined in this table."
        ::= { isdnSignalingGroup 3 }

isdnSignalingStatsEntry OBJECT-TYPE
        SYNTAX      IsdnSignalingStatsEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION



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            "An entry in the ISDN Signaling statistics Table."
        AUGMENTS { isdnSignalingEntry }
        ::= { isdnSignalingStatsTable 1 }

IsdnSignalingStatsEntry ::= SEQUENCE {
            isdnSigStatsInCalls         Counter32,
            isdnSigStatsInConnected     Counter32,
            isdnSigStatsOutCalls        Counter32,
            isdnSigStatsOutConnected    Counter32,
            isdnSigStatsChargedUnits    Counter32
        }

isdnSigStatsInCalls OBJECT-TYPE
        SYNTAX      Counter32
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The number of incoming calls on this interface."
        ::= { isdnSignalingStatsEntry 1 }

isdnSigStatsInConnected OBJECT-TYPE
        SYNTAX      Counter32
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The number of incoming calls on this interface
             which were actually connected."
        ::= { isdnSignalingStatsEntry 2 }

isdnSigStatsOutCalls OBJECT-TYPE
        SYNTAX      Counter32
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The number of outgoing calls on this interface."
        ::= { isdnSignalingStatsEntry 3 }

isdnSigStatsOutConnected OBJECT-TYPE
        SYNTAX      Counter32
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The number of outgoing calls on this interface
             which were actually connected."
        ::= { isdnSignalingStatsEntry 4 }

isdnSigStatsChargedUnits OBJECT-TYPE
        SYNTAX      Counter32



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        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The number of charging units on this interface since
             system startup.
             Only the charging units applying to the local interface,
             i.e. for originated calls or for calls with 'Reverse
             charging' being active, are counted here."
        ::= { isdnSignalingStatsEntry 5 }

--
-- The LAPD table

isdnLapdTable OBJECT-TYPE
        SYNTAX      SEQUENCE OF IsdnLapdEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "Table containing configuration and statistics
             information for all LAPD (D channel Data Link)
             interfaces on this managed device.
             Only statistical information which is not already being
             counted in the ifTable is being defined in this table."
        ::= { isdnSignalingGroup 4 }

isdnLapdEntry OBJECT-TYPE
        SYNTAX      IsdnLapdEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "An entry in the LAPD Table."
        INDEX { ifIndex }
        ::= { isdnLapdTable 1 }

IsdnLapdEntry ::= SEQUENCE {
            isdnLapdPrimaryChannel  TruthValue,
            isdnLapdOperStatus      INTEGER,
            isdnLapdPeerSabme       Counter32,
            isdnLapdRecvdFrmr       Counter32
        }

isdnLapdPrimaryChannel OBJECT-TYPE
        SYNTAX      TruthValue
        MAX-ACCESS  read-write
        STATUS      current
        DESCRIPTION
            "If set to true(1), this D channel is the designated
             primary D channel if D channel backup is active.



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             There must be exactly one primary D channel
             configured. If D channel backup is not used, this
             object has a value of true(1)."
        REFERENCE
            "Q.931 [8], Annex F, D channel backup procedures."
        ::= { isdnLapdEntry 1 }

isdnLapdOperStatus OBJECT-TYPE
        SYNTAX      INTEGER {
            inactive(1),
            l1Active(2),
            l2Active(3)
        }
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The operational status of this interface:

             inactive  all layers are inactive
             l1Active  layer 1 is activated,
                       layer 2 datalink not established
             l2Active  layer 1 is activated,
                       layer 2 datalink established."
        ::= { isdnLapdEntry 2 }

isdnLapdPeerSabme OBJECT-TYPE
        SYNTAX      Counter32
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The number of peer SABME frames received on this
             interface. This is the number of peer-initiated
             new connections on this interface."
        ::= { isdnLapdEntry 3 }

isdnLapdRecvdFrmr OBJECT-TYPE
        SYNTAX      Counter32
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The number of LAPD FRMR response frames received.
             This is the number of framing errors on this
             interface."
        ::= { isdnLapdEntry 4 }

--
-- Optional groups follow here.




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-- The Terminal Endpoint group and table

-- This table is required only if TEI values or SPID numbers
-- have to be entered.
-- The ifIndex values for this table are identical to those of
-- the isdnSignalingChannel table.

isdnEndpointGroup OBJECT IDENTIFIER ::= { isdnMibObjects 4 }

isdnEndpointGetIndex OBJECT-TYPE
        SYNTAX      TestAndIncr
        MAX-ACCESS  read-write
        STATUS      current
        DESCRIPTION
            "The recommended procedure for selecting a new index for
             isdnEndpointTable row creation is to GET the value of
             this object, and then to SET the object with the same
             value. If the SET operation succeeds, the manager can use
             this value as an index to create a new row in this table."
        REFERENCE
            "RFC1903, TestAndIncr textual convention."
        ::= { isdnEndpointGroup 1 }

isdnEndpointTable OBJECT-TYPE
        SYNTAX      SEQUENCE OF IsdnEndpointEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "Table containing configuration for Terminal
             Endpoints."
        ::= { isdnEndpointGroup 2 }

isdnEndpointEntry OBJECT-TYPE
        SYNTAX      IsdnEndpointEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "An entry in the Terminal Endpoint Table. The value
             of isdnEndpointIfType must be supplied for a row
             in this table to become active."
        INDEX { isdnEndpointIndex }
        ::= { isdnEndpointTable 1 }

IsdnEndpointEntry ::= SEQUENCE {
            isdnEndpointIndex       INTEGER,
            isdnEndpointIfIndex     InterfaceIndex,
            isdnEndpointIfType      IANAifType,
            isdnEndpointTeiType     INTEGER,



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            isdnEndpointTeiValue    INTEGER,
            isdnEndpointSpid        DisplayString,
            isdnEndpointStatus      RowStatus
        }

isdnEndpointIndex OBJECT-TYPE
        SYNTAX      INTEGER (1..2147483647)
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "The index value which uniquely identifies an entry
             in the isdnEndpointTable."
        ::= { isdnEndpointEntry 1 }

isdnEndpointIfIndex OBJECT-TYPE
        SYNTAX      InterfaceIndex
        MAX-ACCESS  read-only
        STATUS      current
        DESCRIPTION
            "The ifIndex value of the interface associated with this
             Terminal Endpoint."
        ::= { isdnEndpointEntry 2 }

isdnEndpointIfType OBJECT-TYPE
        SYNTAX      IANAifType
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "The interface type for this Terminal Endpoint.
             Interface types of x25ple(40) and isdn(63) are allowed.
             The interface type is identical to the value of
             ifType in the associated ifEntry."
        ::= { isdnEndpointEntry 3 }

isdnEndpointTeiType OBJECT-TYPE
        SYNTAX      INTEGER {
            dynamic(1),
            static(2)
        }
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "The type of TEI (Terminal Endpoint Identifier)
             used for this Terminal Endpoint. In case of dynamic(1),
             the TEI value is selected by the switch. In
             case of static(2), a valid TEI value has to be
             entered in the isdnEndpointTeiValue object.
             The default value for this object depends on the



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             interface type as well as the Terminal Endpoint type.
             On Primary Rate interfaces the default value is
             static(2). On Basic Rate interfaces the default value
             is dynamic(1) for isdn(63) Terminal Endpoints and
             static(2) for x25ple(40) Terminal Endpoints."
        ::= { isdnEndpointEntry 4 }

isdnEndpointTeiValue OBJECT-TYPE
        SYNTAX      INTEGER ( 0..255 )
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "The TEI (Terminal Endpoint Identifier) value
             for this Terminal Endpoint. If isdnEndpointTeiType
             is set to static(2), valid numbers are 0..63,
             while otherwise the value is set internally.
             The default value of this object is 0 for static
             TEI assignment.
             The default value for dynamic TEI assignment is also
             0 as long as no TEI has been assigned. After TEI
             assignment, the assigned TEI value is returned."
        ::= { isdnEndpointEntry 5 }

isdnEndpointSpid OBJECT-TYPE
        SYNTAX      DisplayString
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "The Service profile IDentifier (SPID) information
             for this Terminal Endpoint.

             The SPID is composed of 9-20 numeric characters.

             This information has to be defined in addition to
             the local number for some switch protocol types,
             e.g. Bellcore NI-1 and NI-2.

             If this object is not required, it is a
             zero length string."
        REFERENCE
            "Bellcore SR-NWT-001953, Generic Guidelines for ISDN
             Terminal Equipment on Basic Access Interfaces,
             Chapter 8.5.1."
        DEFVAL { "" }
        ::= { isdnEndpointEntry 6 }

isdnEndpointStatus OBJECT-TYPE
        SYNTAX      RowStatus



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        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "This object is used to create and delete rows in the
             isdnEndpointTable."
        ::= { isdnEndpointEntry 7 }

--
-- The Directory Number group
--

isdnDirectoryGroup OBJECT IDENTIFIER ::= { isdnMibObjects 5 }

isdnDirectoryTable OBJECT-TYPE
        SYNTAX      SEQUENCE OF IsdnDirectoryEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "Table containing Directory Numbers."
        ::= { isdnDirectoryGroup 1 }

isdnDirectoryEntry OBJECT-TYPE
        SYNTAX      IsdnDirectoryEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "An entry in the Directory Number Table. All objects
             in an entry must be set for a new row to become active."
        INDEX { isdnDirectoryIndex }
        ::= { isdnDirectoryTable 1 }

IsdnDirectoryEntry ::= SEQUENCE {
            isdnDirectoryIndex      INTEGER,
            isdnDirectoryNumber     DisplayString,
            isdnDirectorySigIndex   INTEGER,
            isdnDirectoryStatus     RowStatus
        }

isdnDirectoryIndex OBJECT-TYPE
        SYNTAX      INTEGER ( 1..'7fffffff'h )
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "The index value which uniquely identifies an entry
             in the isdnDirectoryTable."
        ::= { isdnDirectoryEntry 1 }

isdnDirectoryNumber OBJECT-TYPE



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        SYNTAX      DisplayString
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "A Directory Number. Directory Numbers are used
             to identify incoming calls on the signaling
             channel given in isdnDirectorySigIndex.

             The format of this information largely depends on the type
             of switch or PBX the device is connected to. Therefore,
             the detailed format of this information is not
             specified and is implementation dependent.

             If possible, the agent should implement this information
             using the E.164 number format. In this case, the number
             must start with '+'. Otherwise, IA5 number digits must
             be used."
        REFERENCE
            "ITU-T E.164, Q.931 chapter 4.5.10"
        ::= { isdnDirectoryEntry 2 }

isdnDirectorySigIndex OBJECT-TYPE
        SYNTAX      INTEGER (1..2147483647)
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "An index pointing to an ISDN signaling channel.
             Incoming calls are accepted on this
             signaling channel if the isdnDirectoryNumber is
             presented as Called Number in the SETUP message."
        ::= { isdnDirectoryEntry 3 }

isdnDirectoryStatus OBJECT-TYPE
        SYNTAX      RowStatus
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "This object is used to create and delete rows in the
             isdnDirectoryTable."
        ::= { isdnDirectoryEntry 4 }

-- Traps

isdnMibTrapPrefix OBJECT IDENTIFIER ::= { isdnMib 2 }
isdnMibTraps OBJECT IDENTIFIER ::= { isdnMibTrapPrefix 0 }

isdnMibCallInformation NOTIFICATION-TYPE
        OBJECTS {



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            ifIndex,                    -- isdnBearerTable ifIndex
            isdnBearerOperStatus,
            isdnBearerPeerAddress,
            isdnBearerPeerSubAddress,
            isdnBearerCallSetupTime,
            isdnBearerInfoType,
            isdnBearerCallOrigin
        }
        STATUS      current
        DESCRIPTION
            "This trap/inform is sent to the manager under the
             following condidions:
             - on incoming calls for each call which is rejected for
               policy reasons (e.g. unknown neighbor or access
               violation)
             - on outgoing calls whenever a call attempt is determined
               to have ultimately failed. In the event that call retry
               is active, then this will be after all retry attempts
               have failed.
             - whenever a call connects. In this case, the object
               isdnBearerCallConnectTime should be included in the
               trap.

             Only one such trap is sent in between successful or
             unsuccessful call attempts from or to a single neighbor;
             subsequent call attempts result in no trap.

             If the Dial Control MIB objects dialCtlNbrCfgId and
             dialCtlNbrCfgIndex are known by the entity generating
             this trap, both objects should be included in the trap
             as well. The receipt of this trap with no dial neighbor
             information indicates that the manager must poll the
             callHistoryTable of the Dial Control MIB to see what
             changed."
        ::= { isdnMibTraps 1 }

--
-- conformance information
--

isdnMibConformance OBJECT IDENTIFIER ::= { isdnMib 2 }
isdnMibCompliances OBJECT IDENTIFIER ::= { isdnMibConformance 1 }
isdnMibGroups      OBJECT IDENTIFIER ::= { isdnMibConformance 2 }

-- compliance statements

isdnMibCompliance MODULE-COMPLIANCE
        STATUS      current



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        DESCRIPTION
            "The compliance statement for entities which implement
             the ISDN MIB."
        MODULE       -- this module

-- unconditionally mandatory groups
        MANDATORY-GROUPS {
            isdnMibSignalingGroup,
            isdnMibBearerGroup,
            isdnMibNotificationsGroup
        }

-- conditionally mandatory group
        GROUP       isdnMibBasicRateGroup
        DESCRIPTION
            "The isdnMibBasicRateGroup is mandatory for entities
             supporting ISDN Basic Rate interfaces."

-- optional groups
        GROUP       isdnMibEndpointGroup
        DESCRIPTION
            "Implementation of this group is optional for all systems
             that attach to ISDN interfaces."

        GROUP       isdnMibDirectoryGroup
        DESCRIPTION
            "Implementation of this group is optional for all systems
             that attach to ISDN interfaces."

        OBJECT      isdnBasicRateIfType
        MIN-ACCESS  read-only
        DESCRIPTION
            "It is conformant to implement this object as read-only."

        OBJECT      isdnBasicRateLineTopology
        MIN-ACCESS  read-only
        DESCRIPTION
            "It is conformant to implement this object as read-only."

        OBJECT      isdnBasicRateIfMode
        MIN-ACCESS  read-only
        DESCRIPTION
            "It is conformant to implement this object as read-only."

        OBJECT      isdnBasicRateSignalMode
        MIN-ACCESS  read-only
        DESCRIPTION
            "It is conformant to implement this object as read-only."



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        ::= { isdnMibCompliances 1 }

-- units of conformance

isdnMibBasicRateGroup OBJECT-GROUP
        OBJECTS {
            isdnBasicRateIfType,
            isdnBasicRateLineTopology,
            isdnBasicRateIfMode,
            isdnBasicRateSignalMode
        }
        STATUS      current
        DESCRIPTION
            "A collection of objects required for ISDN Basic Rate
             physical interface configuration and statistics."
        ::= { isdnMibGroups 1 }

isdnMibBearerGroup OBJECT-GROUP
        OBJECTS {
            isdnBearerChannelType,
            isdnBearerOperStatus,
            isdnBearerChannelNumber,
            isdnBearerPeerAddress,
            isdnBearerPeerSubAddress,
            isdnBearerCallOrigin,
            isdnBearerInfoType,
            isdnBearerMultirate,
            isdnBearerCallSetupTime,
            isdnBearerCallConnectTime,
            isdnBearerChargedUnits
        }
        STATUS      current
        DESCRIPTION
            "A collection of objects required for ISDN Bearer channel
             control and statistics."
        ::= { isdnMibGroups 2 }

isdnMibSignalingGroup OBJECT-GROUP
        OBJECTS {
            isdnSignalingGetIndex,
            isdnSignalingIfIndex,
            isdnSignalingProtocol,
            isdnSignalingCallingAddress,
            isdnSignalingSubAddress,
            isdnSignalingBchannelCount,
            isdnSignalingInfoTrapEnable,
            isdnSignalingStatus,
            isdnSigStatsInCalls,



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            isdnSigStatsInConnected,
            isdnSigStatsOutCalls,
            isdnSigStatsOutConnected,
            isdnSigStatsChargedUnits,
            isdnLapdPrimaryChannel,
            isdnLapdOperStatus,
            isdnLapdPeerSabme,
            isdnLapdRecvdFrmr
        }
        STATUS      current
        DESCRIPTION
            "A collection of objects required for ISDN D channel
             configuration and statistics."
        ::= { isdnMibGroups 3 }

isdnMibEndpointGroup OBJECT-GROUP
        OBJECTS {
            isdnEndpointGetIndex,
            isdnEndpointIfIndex,
            isdnEndpointIfType,
            isdnEndpointTeiType,
            isdnEndpointTeiValue,
            isdnEndpointSpid,
            isdnEndpointStatus
        }
        STATUS      current
        DESCRIPTION
            "A collection of objects describing Terminal Endpoints."
        ::= { isdnMibGroups 4 }

isdnMibDirectoryGroup OBJECT-GROUP
        OBJECTS {
            isdnDirectoryNumber,
            isdnDirectorySigIndex,
            isdnDirectoryStatus
        }
        STATUS      current
        DESCRIPTION
            "A collection of objects describing directory numbers."
        ::= { isdnMibGroups 5 }

isdnMibNotificationsGroup NOTIFICATION-GROUP
    NOTIFICATIONS { isdnMibCallInformation }
    STATUS        current
    DESCRIPTION
            "The notifications which a ISDN MIB entity is
             required to implement."
    ::= { isdnMibGroups 6 }



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END


5.  Acknowledgments

   This document was produced by the ISDN MIB Working Group.  Special
   thanks is due to the following persons:

           Ed Alcoff
           Fred Baker
           Scott Bradner
           Bibek A. Das
           Maria Greene
           Ken Grigg
           Stefan Hochuli
           Jeffrey T. Johnson
           Glenn Kime
           Oliver Korfmacher
           Kedar Madineni
           Bill Miskovetz
           Mike O'Dowd
           David M. Piscitello
           Lisa A. Phifer
           Randy Roberts
           Hascall H. Sharp
           John Shriver
           Robert Snyder
           Bob Stewart
           Ron Stoughton
           James Watt

6.  References

[1]  SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and
     S. Waldbusser, "Structure of Management Information for Version 2
     of the Simple Network Management Protocol (SNMPv2)", RFC 1902,
     January 1996.

[2]  McCloghrie, K., and M. Rose, Editors, "Management Information Base
     for Network Management of TCP/IP-based internets: MIB-II", STD 17,
     RFC 1213, Hughes LAN Systems, Performance Systems International,
     March 1991.

[3]  Case, J., Fedor, M., Schoffstall, M., and J. Davin, "A Simple
     Network Management Protocol (SNMP)", STD 15, RFC 1157, SNMP
     Research, Performance Systems International, MIT Lab for Computer
     Science, May 1990.




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[4]  SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M. and
     S. Waldbusser, "Protocol Operations for Version 2 of the Simple
     Network Management Protocol (SNMPv2)", RFC 1905, January 1996.

[5]  ITU-T Recommendation "Digital subscriber Signaling System No. 1
     (DSS 1) - ISDN User-Network Interface Data Link Layer - General
     Aspects Rec. Q.920.

[6]  ITU-T Recommendation "Digital subscriber Signaling System No. 1
     (DSS 1) - ISDN User-Network Interface - Data Link Layer
     Specification Rec. Q.921.

[7]  ITU-T Recommendation "Digital subscriber Signaling System No. 1
     (DSS 1) - ISDN Data Link Layer Specification for Frame Mode Bearer
     Services (LAPF) Rec. Q.922.

[8]  ITU-T Recommendation "Digital subscriber Signaling System No. 1
     (DSS 1) - ISDN user-network interface layer 3 specification for
     basic call control", Rec. Q.931(I.451), March 1993.

[9]  ITU-T Recommendation "Generic procedures for the control of ISDN
     supplementary services ISDN user-network interface layer 3
     specification", Rec. Q.932(I.452).

[10] ITU-T Recommendation "Digital subscriber Signaling System No. 1
     (DSS 1) - Signaling specification for frame-mode basic call
     control", Rec. Q.933.

[11] McCloghrie, K. and F. Kastenholz, "Evolution of the Interfaces
     Group of MIB-II", RFC 1573, Hughes LAN Systems, FTP Software,
     January 1994.

[12] Fowler, D., "Definitions of Managed Objects for the DS1/E1/DS2/E2
     Interface Types", Work in Progress.

[13] Fowler, D., "Definitions of Managed Objects for the DS0 and
     DS0Bundle Interface Types", Work in Progress.

[14] ITU-T Recommendation "Integrated Services Digital Network (ISDN)
     General Structure and Service Capabilities - Closed User Group",
     Rec. I.255.1.

[15] Roeck, G., "Dial Control Management Information Base", RFC 2128,
     March 1997.







Roeck                      Standards Track                     [Page 48]

RFC 2127                        ISDN MIB                      March 1997


7.  Security Considerations

   Security issues are not discussed in this memo.

8.  Author's Address

   Guenter Roeck
   cisco Systems
   170 West Tasman Drive
   San Jose, CA 95134
   U.S.A.

   Phone: +1 408 527 3143
   EMail: groeck@cisco.com





































Roeck                      Standards Track                     [Page 49]

