Network Working Group                                 J. Hilgeman, Chair
Request for Comments: 1747                    Apertus Technologies, Inc.
Category: Standards Track                                         S. Nix
                                                          Metaplex, Inc.
                                                               A. Bartky
                                                     Sync Research, Inc.
                                                        W. Clark, Editor
                                                     cisco Systems, Inc.
                                                            January 1995


    Definitions of Managed Objects for SNA Data Link Control (SDLC)
                              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 specification defines an extension to the Management Information
   Base (MIB) for use with SNMP-based network management.  In
   particular, it defines objects for managing the configuration,
   monitoring and control of data link controls in an SNA environment.
   This draft identifies managed objects for SNA Synchronous Data Link
   Control (SDLC) links only.

Table of Contents

   1.     The SNMPv2 Network Management Framework  .................  2
   1.1      Object Definitions  ....................................  2
   2.     Overview  ................................................  2
   2.1      Tables Defined in the SNADLC SDLC MIB  .................  3
   2.2      Row Creation Mechanism  ................................  3
   2.3      Relationship to the Interfaces Group  ..................  4
   3.     Definitions  .............................................  7
   3.1      Port Administrative Table  .............................  9
   3.2      Port Operational Table  ...............................  14
   3.3      Port Statistics Table  ................................  20
   3.4      Link Station Administrative Table  ....................  26
   3.5      Link Station Operational Table  .......................  35
   3.6      Link Station Statistics Table  ........................  44
   3.7      Trap Definitions  .....................................  56
   3.8      Compliance Statements  ................................  57

   4.     Acknowledgments  ........................................  65
   5.     References  .............................................  65
   6.     Glossary  ...............................................  66
   7.     Security Considerations  ................................  67
   8.     Authors' Addresses  .....................................  67

1.  The SNMPv2 Network Management Framework

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

      o    RFC 1441 which defines the SMI, the mechanisms used for
           describing and naming objects for the purpose of management.

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

      o    RFC 1445 which defines the administrative and other
           architectural aspects of the framework.

      o    RFC 1448 which defines the protocol used for network access
           to managed objects.

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

1.1.  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)
   defined in the SMI.  In particular, each object 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.

2.  Overview

   This memo identifies the proposed set of objects for configuring,
   monitoring, and controlling SDLC ports and link stations.

2.1.  Tables Defined in the SNADLC SDLC MIB

   The SNADLC MIB is composed of two managed entities with three tables
   each.  The two managed entities for SDLC are:

     o    Ports: the physical connection, and

     o    Link Stations: the logical connections on the Port.

   The three management tables are:

     o    Adminstration: objects used for configuring and controlling
          the operation of a Port or Link Station,

     o    Operational: objects that reflect the run-time state of the
          Port or Link Station, and

     o    Statistics: objects that reflect the operating metrics of the
          Port or Link Station.

   Considering the above combinations, the following are the actual
   tables found in this MIB:

     1)   Port Administration Table,

     2)   Port Operation Table,

     3)   Port Statistics Table,

     4)   Link Station Administration Table,

     5)   Link Station Operation Table,

     6)   Link Station Statistics Table.

   All variables in this MIB relate to SDLC ports and link stations
   only.  Any variable relating to higher-layer entities in SNA such as
   Physical Units (PU) and Logical Units (LU) are found in the SNA NAU
   MIB [4].

2.2.  Row Creation Mechanism

   Row creation mechanism for the sdlcLSAdminTable is based on the use
   of the RowStatus object.  It follows the rules for the use in SNMPv1
   context proposed in the memo "Row creation with SNMPv1" [5].  Before
   accepting the destroy value for an entry, an agent has to verify the
   operational state of the corresponding entry in the sdlcLSOperTable
   entry.

2.3.  Relationship to the Interfaces Group

   This memo shall conform to the recommendations of [6].

   The SDLC layer of each SDLC Port shall be modeled by a row in the
   ifTable with an ifType using the IANA assigned number for SDLC (17).
   Each SDLC port interface must comply with the following conformance
   groups in [6]:

     - ifGeneralGroup
     - ifStackGroup
     - ifPacketGroup

   An implementation may optionally comply with the ifTestGroup defined
   in that memo to execute vendor specific tests.  An example of this
   would be to perform LPDA test functions.

   The SDLC port's relation with its physical, or lower-layer interface
   (i.e., RS-232, V.35, etc.) shall be modeled by a row in the
   ifStackTable with the ifStackHigherLayer pointing to the SDLC port
   ifTable instance and the ifStackLowerLayer pointing to the physical
   media-specific ifTable instance.  The media-specific objects of these
   lower-layer interfaces will, of course, be described in their
   respective MIBs (i.e., [1]).

   The following table provides specific implementation guidelines for
   all the interface group objects listed in the conformance tables
   above.

Object              Use for an SDLC Port

ifIndex             Each SDLC port is represented by an ifEntry. All
                    SDLC port tables shall be indexed by ifIndex.

ifDescr             Description of the SDLC port.

ifType              The IANA value reserved for SDLC - 17.

ifMtu               Refer to [6].

ifSpeed             This object shall reflect the value of the
                    corresponding object in the ifEntry of the
                    associated lower-layer interface.

ifPhysAddress       A string denoting the physical location of the SDLC
                    port within its node.  This shall have unique
                    significance within each implementing node.

ifAdminStatus       This object shall reflect the value of the
                    corresponding object in the ifEntry of the
                    associated lower-layer interface.

ifOperStatus        This object shall reflect the value of the
                    corresponding object in the ifEntry of the
                    associated lower-layer interface.

ifLastChange        Refer to [6].

ifInOctets          Refer to [6].

ifInUcastPkts       This object shall count packets received from a
                    specific SDLC poll address.  Packets for the SDLC
                    broadcast address of x'FF' are not counted.

ifInDiscards        Refer to [6].

ifInErrors          Refer to [6].  Specific counters for these errors
                    are kept in the sdlcPortStatsTable.

ifInUnknownProtos   This counter shall return zero for SDLC ports.

ifOutOctets         Refer to [6].

ifOutUcastPkts      This object shall count packets transmitted to a
                    specific SDLC poll address (not x'FF').

ifOutDiscards       Refer to [6].

ifOutErrors         Refer to [6].  Specific counters for these errors
                    are kept in the sdlcPortStatsTable.

ifName              The textual name of the SDLC port or an octet string
                    of zero length.

ifInMulticastPkts   The value is 0 (not applicable to the SDLC layer).

ifInBroadcastPkts   This object shall count packets received on this
                    interface addressed to the SDLC broadcast address
                    (x'FF').  Only point-to-point ports supporting a
                    secondary switched station should return non-zero
                    values.

ifOutMulticastPkts  The value is 0 (not applicable to the SDLC layer).

ifOutBroadcastPkts  This object shall count packets transmitted on this
                    interface which were addressed to the SDLC broadcast

                    address (x'FF').  Only point-to-point ports
                    supporting a primary switched station should
                    return non-zero values.

ifHC*               Not part of the conformance group.

ifLinkUpDownTrapEnable
                    Refer to [6].  Default is disabled (2).

ifHighSpeed         Refer to [6].

ifPromiscuousMode   Should return false if this interface receives only
                    packets addressed to its SDLC poll address(es).
                    However, in certain implementations, the lower-layer
                    interface shall present all frames to the SDLC port
                    regardless of the poll address.  Such frames may be
                    the result of a misconfigured peer or the secondary
                    end of a multipoint connection.  Such
                    implementations should return true for this
                    object.

ifConnectorPresent  Set to 'false'.

ifStackHigherLayer  For each SDLC port there will be an ifStackEntry
                    with this object's value referring to the ifIndex of
                    the SDLC port's ifEntry for the SDLC layer.

ifStackLowerLayer   For each SDLC port there will be an ifStackEntry
                    with this object's value referring to the ifIndex of
                    the physical layer interface's ifEntry for that SDLC
                    port.

ifStackStatus       Refer to [6].