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LinuxDig.com Request For Comments

RFC Number : 2127

Title : ISDN Management Information Base using SMIv2.






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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RFC 2127 ISDN MIB March 1997


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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RFC 2127 ISDN MIB March 1997


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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RFC 2127 ISDN MIB March 1997


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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RFC 2127 ISDN MIB March 1997


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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RFC 2127 ISDN MIB March 1997


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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RFC 2127 ISDN MIB March 1997


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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RFC 2127 ISDN MIB March 1997


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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RFC 2127 ISDN MIB March 1997


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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RFC 2127 ISDN MIB March 1997


::= { 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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RFC 2127 ISDN MIB March 1997


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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RFC 2127 ISDN MIB March 1997


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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RFC 2127 ISDN MIB March 1997


[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.







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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





































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