LAPB MIB

"Dean D. Throop" <throop@dg-rtp.dg.com> Wed, 05 February 1992 23:18 UTC

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Date: Wed, 05 Feb 1992 17:14:15 -0500
From: "Dean D. Throop" <throop@dg-rtp.dg.com>
Message-Id: <9202052214.AA07899@commtg3>
To: x25mib@dg-rtp.dg.com
Subject: LAPB MIB

Here is the latest version of the LAPB MIB.  Please
review and send comments to the mailing list.

Dean Throop		throop@dg-rtp.dg.com



          Internet Draft             LAPB MIB              February 1992


                           SNMP MIB extension for LAPB

                                 February 5, 1992


                                  Dean D. Throop
                                    Fred Baker

                             Data General Corporation
                                 62 Alexander Dr.
                         Research Triangle Park, NC 27709

                         Advanced Computer Communications
                             720 Santa Barbara Street
                             Santa Barbara, CA 93101

                               throop@dg-rtp.dg.com
                                  fbaker@acc.com






          1.  Status of this Memo

          This is the fourth draft of this document produced by the
          x25mib working group. Eventually this document will be
          submitted to the RFC editor as an extension to the SNMP MIB.
          Distribution of this memo is unlimited.  Please send comments
          to the x25mib working group at:

                               x25mib@dg-rtp.dg.com


          1.1.  Revision History

          February 1992

          The February 1992 revision of this document (Editor's Internal
          Reference 1.17) incorporated the following changes:

               The name was changed from HDLC to LAPB. This change was
               made because other flavors of HDLC such as LAPD, SDLC,
               and raw HDLC framing, are different enough that this MIB





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               will not adequately manage them.

               The Historical Perspective section at the beginning of
               the document has been replaced with a more concise
               Network Management Framework section.

               The name lapbParmKWindowSize was changed to
               lapbParmTransmitKWindowSize and the object
               lapbParmReceiveKWindowSize was added. This change was
               made because section 5.7.4 of ISO 7776 and Table 3 of ISO
               8885 have provisions for different values for the
               transmit and receive window size.

               The name lapbParmN1FrameSize was changed to
               lapbParmTransmitN1FrameSize and the object
               lapbParmReceiveN1FrameSize was added. This change was
               made because section 5.7.3 of ISO 7776 and Table 3 of ISO
               8886 have provisions for different values for the
               transmit and receive maximum frame size.

               The object lapbParmPortIndex was deleted and the
               description of lapbParmPortId was changed.  The object
               lapbParmPortId now identifies an instance of the index
               object for the MIB of the physical device or interface
               below lapb.

               The units for the timers were changed to Milliseconds to
               be consistent with ISO 8885; see table 3.

               The objects lapbParamT2AckDelayTimer and
               lapbParamT3DisconnectTimer both allow values of 0 to
               indicate the timer is not being used.

               The object lapbParamT4IdleTimer has a value to indicate
               timer not in use.

               The object lapbFlowXidReceived was added to the flow
               table.

               The lapbDefTable was added.

               Ranges and sizes were added for all INTEGERs and OCTET
               STRINGs that didn't have them.







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          October 1991

          The October 1991 revision of this document basically changed
          the name from LAPB to HDLC to make the objects more
          appropriate for a broader range of uses.  A number of minor
          changes were made to bring the objects in line with
          established conventions.  These changes are as follows.

               The enumerated values of hdlcParmStationType were
               renumbered from 0 and 1 to 1 and 2.

               The object hdlcFlowBusyDefer was renamed
               hdlcFlowBusyDefers.

               The object hdlcFlowRejSent was rename hdlcFlowRejOutPkts.

               The object hdlcFlowRejReceived was renamed
               hdlcFlowRejInPkts.

          June 1991

          The June revision of this document incorporated much of the
          E-mail discussion of the first draft. In particular it
          replaced the lapbStatTable (and all contents) with the
          lapbFlowTable.

          April 1991

          The April 24 version of this document was the first release.
          At that time this document was basically a bunch of objects
          synthesized from various vendor MIBs and a quick reading of
          ISO 7776 [10].  On first reading it appeared to instrument too
          many LAPB normal functions and too few exceptional conditions.
          The lapbStatTable was too long and needed to be redone.

          2.  Abstract

          This memo defines an experimental portion of the Management
          Information Base (MIB) for use with network management
          protocols in TCP/IP-based internets.  In particular, it
          defines objects for managing the Link Layer of X.25, LAPB.
          The objects defined here, along with the objects in the "SNMP
          MIB extension for the Packet Layer of X.25"[9] and the
          "Definitions of Managed Objects for RS-232-like Hardware
          Devices"[8], combine to allow management of an X.25 protocol





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          stack.

















































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          3.  The Network Management Framework

          The Internet-standard Network Management Framework consists of
          three components.  These components give the rules for
          defining objects, definitions of objects, and the protocol for
          manipulating objects.

          The Network management framework structures objects in
          abstract information tree. The branches of the tree name
          objects and the leaves of the tree contain the values
          manipulated to effect management. This tree is called the
          Management Information Base or MIB. The concepts of this tree
          are given in RFC 1155 "The Structure of Management
          Information" or SMI [1]. The SMI defines the trunk of the tree
          and the types of objects used when defining the leaves. RFC
          1212, "Towards Concise MIB Definitions" [4], defines a more
          concise description mechanism that preserves all the
          principals of the SMI.

          The core MIB definitions for the Internet suite of protocols
          can be found in RFC 1156 [2] "Management Information Base for
          Network Management of TCP/IP-based internets". RFC 1213 [5]
          defines MIB-II, an evolution of MIB-I with changes to
          incorporate implementation experience and new operational
          requirements.

          RFC 1157 [3] defines the SNMP protocol itself. The protocol
          defines how to manipulate the objects in a remote MIB.

          The tree structure of the MIB allows new objects to be defined
          for the purpose of experimentation and evaluation.

          4.  Objects

          The definition of an object in the MIB requires an object name
          and type.  Object names and types are defined using the subset
          of Abstract Syntax Notation One (ASN.1) [6] defined in the SMI
          [1]. Objects are named using ASN.1 object identifiers,
          administratively assigned names, to specify object types. The
          object name, together with an optional object instance,
          uniquely identifies a specific an instance of an object. For
          human convenience, we often use a textual string, termed the
          OBJECT DESCRIPTOR, to also refer to objects.







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          Objects also have a syntax that defines the abstract data
          structure corresponding to that object type.  The ASN.1
          language [6] provides the primitives used for this purpose.
          The SMI [1] purposely restricts the ASN.1 constructs which may
          be used for purposes of simplicity and ease of implementation.
          The encoding of an object type simply describes how to
          represent an object using ASN.1 encoding rules [7], for
          purposes of dealing with the SNMP protocol.

          4.1.  Format of Definitions

          Section 6 contains the specification of all object types
          defined in this MIB module. The object definitions use the
          conventions given in the SMI [1] as amended by the concise MIB
          definitions [4].



































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          5.  Overview

          5.1.  Informal overview

          This section describes how the objects defined below relate
          with other MIBs.  This section is only informational to help
          understand how the pieces fit together.

          The objects defined below are to be used in conjunction with
          MIB-II and other MIBs such as the X.25 packet level MIB [9].
          A system with a complete X.25 stack running over a synchronous
          line will have at least two interfaces in the ifTable defined
          in MIB-II.  There will be an interface for LAPB and another
          interface for the packet layer of X.25. There will also be
          objects defined in the RS-232-like MIB for the physical sync
          line.

          Each software interface identifies the layer below it used to
          send and receive packets. The X.25 MIB object,
          x25InfoDataLinkId, specifies an instance of lapbParamIndex for
          the LAPB interface under that X.25. The LAPB object, defined
          below, lapbParamPortId, identifies an instance of the
          4s232PortIndex for the the Sync line used by LAPB.

          For X.25 running over LAPB over Ethernet, the lapbParamPortId
          would identify the instance of ifIndex for the Ethernet
          interface.

          Each X.25 subnetwork will have separate entries in the
          ifTable.  Thus a system with two X.25 lines would have two
          ifTable entries for the two X.25 packet layers and two other
          entries for the two LAPB interfaces. Each X.25 Packet Layer
          MIB would identify the instance of the LAPB MIB below it. Each
          LAPB MIB would identify the Sync line below it. The system
          would also have two entries for rs232PortTable and
          rs232SyncPortTable for the two physical lines.

          Since the ifTable as defined in MIB-II is device independent,
          it doesn't have anything specific for any type of interface.
          The objects below define the LAPB specific information for an
          interface of type LAPB. Different LAPB interfaces can also be
          differentiated by matching the values of ifIndex with
          lapbParamIndex.







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          5.2.  Formal overview

          Instances of the objects defined below represent attributes of
          a LAPB interface.  LAPB interfaces are identified by an ifType
          object in the Internet-standard MIB [5] of

                    lapb(16).

          For these interfaces, the value of the ifSpecific variable in
          the MIB-II [5] has the OBJECT IDENTIFIER value:

                    lapb    OBJECT IDENTIFIER ::= { To Be Assigned }

          The relationship between a LAPB interface and an interface in
          the context of the Internet-standard MIB [5] is one-to-one.
          As such, the value of an ifIndex object instance can be
          directly used to identify corresponding instances of the
          objects defined below.

          The objects defined below are defined in the context of ISO
          7776 [10] and ISO 8885 [11].  Access to those documents maybe
          useful (but isn't essential) to understand the names and
          semantics of some objects.  To the extent that some attributes
          defined in the Internet standard MIB [5] are applicable to
          LAPB, those objects have not been duplicated here.  In some
          instances some clarification of how to apply those objects to
          LAPB has been given.























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          6.  Object Definitions


          RFClapb-MIB DEFINITIONS ::= BEGIN
                  -- (Editors internal reference 1.48)

          IMPORTS
                  experimental, Counter
                          FROM RFC1155-SMI
                  OBJECT-TYPE
                          FROM RFC-1212;


                          --  LAPB MIB

                          -- DO NOT USE THIS EXPERIMENTAL NUMBER.
          lapb    OBJECT IDENTIFIER ::= { experimental 123456 }
                          -- This experimental number is an
                          -- invalid placeholder.
                          -- DO NOT USE THIS EXPERIMENTAL NUMBER.


          --      LAPB    configuration parameters

          lapbParmTable   OBJECT-TYPE
                  SYNTAX  SEQUENCE OF LapbParmEntry
                  ACCESS  not-accessible
                  STATUS  mandatory
                  DESCRIPTION
                          "The  Parm  table   contains   configuration
                          information   about   interface   parameters
                          currently set in the interface."
                  ::= { lapb 1 }

          lapbParmEntry   OBJECT-TYPE
                  SYNTAX  LapbParmEntry
                  ACCESS  not-accessible
                  STATUS  mandatory
                  DESCRIPTION
                          "Currently  set  parameter  values   for   a
                          specific LAPB."
                  INDEX { lapbParmIndex }
                  ::= { lapbParmTable 1 }

          LapbParmEntry ::= SEQUENCE {





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             lapbParmIndex
                          INTEGER,
                  lapbParmStationType
                          INTEGER,
                  lapbParmControlField
                          INTEGER,
                  lapbParmTransmitKWindowSize
                          INTEGER,
                  lapbParmReceiveKWindowSize
                          INTEGER,
                  lapbParmTransmitN1FrameSize
                          INTEGER,
                  lapbParmReceiveN1FrameSize
                          INTEGER,
                  lapbParmN2RxmitCount
                          INTEGER,
                  lapbParmT1AckTimer
                          INTEGER,
                  lapbParmT2AckDelayTimer
                          INTEGER,
                  lapbParmT3DisconnectTimer
                          INTEGER,
                  lapbParmT4IdleTimer
                          INTEGER,
                  lapbParmActionInitiate
                          INTEGER,
                  lapbParmActionRecvDM
                          INTEGER,
                  lapbParmPortId
                          OBJECT IDENTIFIER
                  }

          lapbParmIndex   OBJECT-TYPE
                  SYNTAX  INTEGER (1..65535)
                  ACCESS  read-only
                  STATUS  mandatory
                  DESCRIPTION
                          "An index value that uniquely identifies  an
                          LAPB  interface.   This  value will match an
                          ifIndex entry identifying the MIB-II ifTable
                          objects for this same interface."
                  ::= { lapbParmEntry 1 }

          lapbParmStationType     OBJECT-TYPE
                  SYNTAX  INTEGER {





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                  dte(1),
                          dce(2)
                          }
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 7776 section 3.1
                  DESCRIPTION
                          "Identifies  the  station   type   of   this
                          interface."
                  ::= { lapbParmEntry 2 }

          lapbParmControlField OBJECT-TYPE
                  SYNTAX  INTEGER {
                                  modulo8(1),
                                  modulo128(2)
                          }
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 7776 section 3.3
                  DESCRIPTION
                          "The size of the sequence  numbers  used  to
                          number frames."
                  ::= { lapbParmEntry 3 }

          lapbParmTransmitKWindowSize OBJECT-TYPE
                  SYNTAX  INTEGER (1..127)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 7776 section 5.7.4
                  DESCRIPTION
                          "The PDU window size this Interface uses  to
                          transmit.   This  is  the  maximum number of
                          unacknowledged sequenced PDUs  that  may  be
                          outstanding from this DTE at any one time."
                  ::= { lapbParmEntry 4 }

          lapbParmReceiveKWindowSize OBJECT-TYPE
                  SYNTAX  INTEGER (1..127)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 7776 section 5.7.4
                  DESCRIPTION
                          "The  receive  PDU  window  size  for   this
                          Interface.   This  is  the maximum number of
                          unacknowledged sequenced PDUs  that  may  be





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                  outstanding  from  the DCE/remote DTE at any
                          one time."
                  ::= { lapbParmEntry 5 }


          lapbParmTransmitN1FrameSize OBJECT-TYPE
                  SYNTAX  INTEGER (1080..65648)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 7776 section 5.7.3.
                  -- 65640 = (8196 + 10) * 8
                  -- where 10 is twice the I frame control overhead
                  -- and 8196 is twice the maximum x25 packet size
                  -- and 8 is number of bits per octet.
                  DESCRIPTION
                          "The N1 frame  size  specifies  the  maximum
                          number  of  bits  in  a  frame  this DTE can
                          transmit.  This excludes flags  and  0  bits
                          inserted for transparency."
                  ::= { lapbParmEntry 6 }

          lapbParmReceiveN1FrameSize OBJECT-TYPE
                  SYNTAX  INTEGER (1080..65648)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See lapbParmTrasnmitN1FrameSize
                  DESCRIPTION
                          "The N1 frame  size  specifies  the  maximum
                          number of bits in a frame the DCE/remote DTE
                          can transmit.  This  excludes  flags  and  0
                          bits inserted for transparency."
                  ::= { lapbParmEntry 7 }

          lapbParmN2RxmitCount    OBJECT-TYPE
                  SYNTAX  INTEGER (1..255)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 7776 section 5.7.2
                  DESCRIPTION
                          "The  N2  retry  counter   used   for   this
                          interface.   This  specifies  the  number of
                          times a PDU will  be  resent  after  the  T1
                          timer expires without an acknowledgement for
                          the PDU."
                  ::= { lapbParmEntry 8 }





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          lapbParmT1AckTimer      OBJECT-TYPE
                  SYNTAX  INTEGER (1..1800000)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- The maximum time representable is 30 minutes.
                  -- See ISO 7776 section 5.7.1.1
                  DESCRIPTION
                          "The T1  timer  for  this  interface.   This
                          specifies  the  maximum time in Milliseconds
                          to wait for acknowledgment of a PDU."
                  ::= { lapbParmEntry 9 }

          lapbParmT2AckDelayTimer         OBJECT-TYPE
                  SYNTAX  INTEGER (0..1800000)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 7776 section 5.7.1.2
                  DESCRIPTION
                          "The T2  timer  for  this  interface.   This
                          specifies  the  maximum time in Milliseconds
                          to wait before sending an acknowledgment for
                          a  sequenced  PDU.   A  value  of zero means
                          there will be no  delay  in  acknowledgement
                          generation."
                  ::= { lapbParmEntry 10 }

          lapbParmT3DisconnectTimer OBJECT-TYPE
                  SYNTAX  INTEGER (0..1800000)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 7776 section 5.7.1.3
                  DESCRIPTION
                          "The T3  timer  for  this  interface.   This
                          specifies  the  time in Milliseconds to wait
                          before considering the link disconnected.  A
                          value  of  zero  indicates  the link will be
                          considered disconnected upon  completion  of
                          the packet exchange to disconnect the link."
                  ::= { lapbParmEntry 11 }

          lapbParmT4IdleTimer OBJECT-TYPE
                  SYNTAX  INTEGER (1..2147483647)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 7776 section 5.7.1.4





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             DESCRIPTION
                          "The T4  timer  for  this  interface.   This
                          specifies  the  maximum time in Milliseconds
                          to allow without frames being  exchanged  on
                          the   data  link.   A  value  of  2147483647
                          indicates no idle timer is being kept."
                  ::= { lapbParmEntry 12 }


          lapbParmActionInitiate OBJECT-TYPE
                  SYNTAX  INTEGER {
                                  sendSABM (1),
                                  sendDISC (2),
                                  sendDM (3),
                                  none (4),
                                  other (5)
                          }
                  ACCESS  read-write
                  STATUS  mandatory
                  DESCRIPTION
                          "This identifies the action LAPB  will  take
                          to initiate link set-up."
                  ::= { lapbParmEntry 13 }

          lapbParmActionRecvDM OBJECT-TYPE
                  SYNTAX  INTEGER {
                                  sendSABM (1),
                                  sendDISC (2),
                                  other (3)
                          }
                  ACCESS  read-write
                  STATUS  mandatory
                  DESCRIPTION
                          "This identifies the action LAPB  will  take
                          when it receives a DM response."
                  ::= { lapbParmEntry 14 }

          lapbParmPortId OBJECT-TYPE
                  SYNTAX  OBJECT IDENTIFIER
                  ACCESS  read-only
                  STATUS  mandatory
                  DESCRIPTION
                          "An instance of  the  index  object  in  the
                          first  group  of objects in the MIB specific
                          to the physical device or interface used  to





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                  send  and  receive frames.  If an agent does
                          not support  any  such  objects,  it  should
                          return nullSpec OBJECT IDENTIFIER {0 0}."
                  ::= { lapbParmEntry 15 }




                                  -- LAPB Flow Table

          --      This table defines LAPB Flow Statistics
          --      and other information recorded by the interface.

          lapbFlowTable OBJECT-TYPE
                  SYNTAX  SEQUENCE OF LapbFlowEntry
                  ACCESS  not-accessible
                  STATUS  mandatory
                  DESCRIPTION
                          "A list of managed  objects  recording  flow
                          controls in LAPB, and their effects."
                  ::= { lapb 2 }

          lapbFlowEntry OBJECT-TYPE
                  SYNTAX  LapbFlowEntry
                  ACCESS  not-accessible
                  STATUS  mandatory
                  DESCRIPTION
                          "The information regarding  the  effects  of
                          flow controls in LAPB."
                   INDEX { lapbFlowIfIndex }
                  ::= { lapbFlowTable 1 }

          LapbFlowEntry ::= SEQUENCE {
                  lapbFlowIfIndex
                          INTEGER,
                  lapbFlowStateChanges
                          Counter,
                  lapbFlowChangeReason
                          INTEGER,
                  lapbFlowCurrentMode
                          INTEGER,
                  lapbFlowBusyDefers
                          Counter,
                  lapbFlowRejOutPkts
                          Counter,





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             lapbFlowRejInPkts
                          Counter,
                  lapbFlowT1Timeouts
                          Counter,
                  lapbFlowFrmrSent
                          OCTET STRING,
                  lapbFlowFrmrReceived
                          OCTET STRING,
                  lapbFlowXidReceived
                          OCTET STRING
                  }

          lapbFlowIfIndex OBJECT-TYPE
                  SYNTAX  INTEGER (1..65535)
                  ACCESS  read-only
                  STATUS  mandatory
                  DESCRIPTION
                          "The value of ifIndex corresponding to  this
                          LAPB Interface."
                  ::= { lapbFlowEntry 1 }

          lapbFlowStateChanges OBJECT-TYPE
                  SYNTAX  Counter
                  ACCESS  read-only
                  STATUS  mandatory
                  DESCRIPTION
                          "The number of LAPB State Changes, including
                          resets."
                  ::= { lapbFlowEntry 2 }

          lapbFlowChangeReason OBJECT-TYPE
                  SYNTAX  INTEGER {
                                  notStarted (1),    -- Initial state
                                  abmEntered (2),    -- SABM or UA
                                  abmeEntered (3),   -- SABME or UA
                                  abmReset (4),      -- SABM in ABM
                                  abmeReset (5),     -- SABME in ABME
                                  dmReceived (6),    -- DM Response
                                  dmSent (7),        -- DM sent
                                  discReceived (8),  -- DISC Response
                                  discSent (9),      -- DISC Sent
                                  frmrReceived (10), -- FRMR Received
                                  frmrSent (11),     -- FRMR Sent
                                  n2Timeout (12),    -- N2 Timer Expired
                                  other (13)





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                    }
                  ACCESS  read-only
                  STATUS  mandatory
                  DESCRIPTION
                          "The reason for the most recent incrementing
                          of lapbFlowStateChanges.  A DM or DISC frame
                          generated to initiate link set-up  does  not
                          alter  this  object.  When the MIB-II object
                          ifOperStatus  does  not  have  a  value   of
                          testing,  there exists a correlation between
                          this object and ifOperStatus.   IfOperStatus
                          will  have  a  value  of up when this object
                          contains:      abmEntered,      abmeEntered,
                          abmReset,  or  abmeReset.  IfOperStatus will
                          have a value of down when this object has  a
                          value  of  notStarted, or dmReceived through
                          n2Timeout.  There  is  no  correlation  when
                          this object has the value other."
                  ::= { lapbFlowEntry 3 }

          lapbFlowCurrentMode OBJECT-TYPE
                  SYNTAX  INTEGER {
                                  ndm(1), -- Normal Disconnected Mode
                                  abm(2), -- Asynchronous Balanced Mode
                                  abme(3) -- Asynchronous Balanced Mode
                                          -- Extended
                            }
                  ACCESS  read-only
                  STATUS  mandatory
                  DESCRIPTION
                          "The current mode of the conversation."
                  ::= { lapbFlowEntry 4 }

          lapbFlowBusyDefers OBJECT-TYPE
                  SYNTAX  Counter
                  ACCESS  read-only
                  STATUS  mandatory
                  DESCRIPTION
                          "The number of times this device was  unable
                          to  transmit  a  frame  due  to  a perceived
                          remote busy condition.  Busy conditions  can
                          result  from  the receipt of an RNR from the
                          remote device, the lack  of  valid  sequence
                          number  space  (window saturation), or other
                          conditions."





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             ::= { lapbFlowEntry 5 }

          lapbFlowRejOutPkts OBJECT-TYPE
                  SYNTAX  Counter
                  ACCESS  read-only
                  STATUS  mandatory
                  DESCRIPTION
                          "The number of REJ or SREJ  frames  sent  by
                          this station."
                  ::= { lapbFlowEntry 6 }

          lapbFlowRejInPkts OBJECT-TYPE
                  SYNTAX  Counter
                  ACCESS  read-only
                  STATUS  mandatory
                  DESCRIPTION
                          "The number of REJ or SREJ  frames  received
                          by this station."
                  ::= { lapbFlowEntry 7 }

          lapbFlowT1Timeouts OBJECT-TYPE
                  SYNTAX  Counter
                  ACCESS  read-only
                  STATUS  mandatory
                  DESCRIPTION
                          "The number of times a  re-transmission  was
                          effected by the T1 Timer expiring."
                  ::= { lapbFlowEntry 8 }

          lapbFlowFrmrSent OBJECT-TYPE
                  SYNTAX  OCTET STRING (SIZE (0..7))
                  ACCESS  read-only
                  STATUS  mandatory
                  -- See ISO 7776 Section 4.3.9, tables 7 and 8
                  DESCRIPTION
                          "The Information  Field  of  the  FRMR  most
                          recently  sent.   If  no  FRMR has been sent
                          (the normal case) or the  information  isn't
                          available,  this  will be an OCTET STRING of
                          zero length."
                  ::= { lapbFlowEntry 9 }

          lapbFlowFrmrReceived OBJECT-TYPE
                  SYNTAX  OCTET STRING (SIZE (0..7))
                  ACCESS  read-only





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             STATUS       mandatory
                  -- See ISO 7776 Section 4.3.9, tables 7 and 8
                  DESCRIPTION
                          "The Information  Field  of  the  FRMR  most
                          recently  received.   If  no  FRMR  has been
                          received   (the   normal   case)   or    the
                          information isn't available, this will be an
                          OCTET STRING of zero length."
                  ::= { lapbFlowEntry 10 }

          lapbFlowXidReceived OBJECT-TYPE
                  SYNTAX  OCTET STRING (SIZE (0..8206))
                  ACCESS  read-only
                  STATUS  mandatory
                  -- See ISO 8885
                  DESCRIPTION
                          "The Information Field of the XID frame most
                          recently received.  If no XID frame has been
                          received, this will be an  OCTET  STRING  of
                          zero length."
                  ::= { lapbFlowEntry 11 }





                                  -- LAPB Defaults Table

          --      This table defines LAPB default values which maybe
          --      changed or used in link initialization negotiation.

          lapbDefTable    OBJECT-TYPE
                  SYNTAX  SEQUENCE OF LapbDefEntry
                  ACCESS  not-accessible
                  STATUS  mandatory
                  DESCRIPTION
                          "The    Def    table    contains     default
                          configuration  that maybe different from the
                          values actually in  use.   For  example  the
                          default  maybe  to  use  modulo128  sequence
                          numbers but upon receiving a  SABM,  modulo8
                          sequence   numbers   are  in  use.   An  XID
                          exchange may also  alter  the  configuration
                          actually in use."
                  ::= { lapb 3 }





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          lapbDefEntry    OBJECT-TYPE
                  SYNTAX  LapbDefEntry
                  ACCESS  not-accessible
                  STATUS  mandatory
                  DESCRIPTION
                          "Default parameter  values  for  a  specific
                          LAPB."
                  INDEX { lapbDefIndex }
                  ::= { lapbDefTable 1 }

          LapbDefEntry ::= SEQUENCE {
                  lapbDefIndex
                          INTEGER,
                  lapbDefAdRIdentifier
                          OCTET STRING,
                  lapbDefAdRAddress
                          OCTET STRING,
                  lapbDefParameterUniqueIdentifier
                          OCTET STRING,
                  lapbDefControlField
                          INTEGER,
                  lapbDefGroupAddress
                          OCTET STRING,
                  lapbDefTransmitN1FrameSize
                          INTEGER,
                  lapbDefReceiveN1FrameSize
                          INTEGER,
                  lapbDefTransmitKWindowSize
                          INTEGER,
                  lapbDefReceiveKWindowSize
                          INTEGER,
                  lapbDefN2RxmitCount
                          INTEGER,
                  lapbDefT1AckTimer
                          INTEGER,
                  lapbDefT2AckDelayTimer
                          INTEGER,
                  lapbDefPortNumber
                          OCTET STRING,
                  lapbDefUserDataSubfield
                          OCTET STRING
                  }

          lapbDefIndex    OBJECT-TYPE
                  SYNTAX  INTEGER (1..65535)





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             ACCESS       read-only
                  STATUS  mandatory
                  DESCRIPTION
                          "An index value that uniquely identifies  an
                          LAPB  interface.   This  value will match an
                          ifIndex entry identifying the MIB-II ifTable
                          objects for this same interface."
                  ::= { lapbDefEntry 1 }


          lapbDefAdRIdentifier OBJECT-TYPE
                  SYNTAX  OCTET STRING (SIZE (0..255))
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 8885 Table 2, Name: Identifier
                  DESCRIPTION
                          "The  value  of   the   Address   Resolution
                          Identifier.   A zero length string indicates
                          no Identifier value has been assigned."
                  ::= { lapbDefEntry 2 }

          lapbDefAdRAddress OBJECT-TYPE
                  SYNTAX  OCTET STRING (SIZE (0..255))
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 8885 Table 2, Name: Address
                  DESCRIPTION
                          "The  value  of   the   Address   Resolution
                          Address.   A zero length string indicates no
                          Address value has been assigned."
                  ::= { lapbDefEntry 3 }

          lapbDefParameterUniqueIdentifier OBJECT-TYPE
                  SYNTAX  OCTET STRING (SIZE (0..255))
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 8885 Table 3, Name: Identifier
                  DESCRIPTION
                          "The   value   of   the   parameter   unique
                          Identifier.   A zero length string indicates
                          no  Unique   identifier   value   has   been
                          assigned."
                  ::= { lapbDefEntry 4 }

          lapbDefControlField OBJECT-TYPE





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             SYNTAX       INTEGER {
                                  modulo8(1),
                                  modulo128(2)
                          }
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 8885 Table 3, Name: HDLC Option - 10
                  DESCRIPTION
                          "The desired size of  the  sequence  numbers
                          used to number frames."
                  ::= { lapbDefEntry 5 }

          lapbDefGroupAddress OBJECT-TYPE
                  SYNTAX  OCTET STRING (SIZE (0..255))
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 8885 Table 3, Name: Group address
                  DESCRIPTION
                          "The value of the parameter  Group  address.
                          A  zero  length  string  indicates  no Group
                          address value has been assigned."
                  ::= { lapbDefEntry 6 }

          lapbDefTransmitN1FrameSize OBJECT-TYPE
                  SYNTAX  INTEGER (1080..65648)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 8885 Table 3,Name: Information Field length
                  -- See lapbParmTransmitN1FrameSize above
                  DESCRIPTION
                          "The default maximum N1 frame  size  desired
                          in number of bits for a frame transmitted by
                          this DTE.  This excludes flags  and  0  bits
                          inserted for transparency."
                  ::= { lapbDefEntry 7 }

          lapbDefReceiveN1FrameSize OBJECT-TYPE
                  SYNTAX  INTEGER (1080..65648)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See lapbDefTrasnmitN1FrameSize
                  DESCRIPTION
                          "The default maximum N1 frame  size  desired
                          in number of bits for a frame the DCE/remote
                          transmits to this DTE.  This excludes  flags





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                  and 0 bits inserted for transparency."
                  ::= { lapbDefEntry 8 }


          lapbDefTransmitKWindowSize OBJECT-TYPE
                  SYNTAX  INTEGER (1..127)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 8885 Table 3, Name: Window size
                  DESCRIPTION
                          "The default transmit window size  for  this
                          Interface.   This  is  the maximum number of
                          unacknowledged sequenced PDUs  that  may  be
                          outstanding from this DTE at any one time."
                  ::= { lapbDefEntry 9 }

          lapbDefReceiveKWindowSize OBJECT-TYPE
                  SYNTAX  INTEGER (1..127)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See lapbDefTransmitKWindowSize
                  DESCRIPTION
                          "The default receive window  size  for  this
                          Interface.   This  is  the maximum number of
                          unacknowledged sequenced PDUs  that  may  be
                          outstanding  from  the DCE/remote DTE at any
                          one time."
                  ::= { lapbDefEntry 10 }

          lapbDefN2RxmitCount     OBJECT-TYPE
                  SYNTAX  INTEGER (1..255)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 8885 Table 3, Name: Retransmission Attempts
                  DESCRIPTION
                          "The  default  N2  retry  counter  for  this
                          interface.   This  specifies  the  number of
                          times a PDU will  be  resent  after  the  T1
                          timer expires without an acknowledgement for
                          the PDU."
                  ::= { lapbDefEntry 11 }

          lapbDefT1AckTimer       OBJECT-TYPE
                  SYNTAX  INTEGER (1..1800000)
                  ACCESS  read-write





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             STATUS       mandatory
                  -- See ISO 8885 Table 3, Name: Acknowledgement timer
                  DESCRIPTION
                          "The default T1 timer  for  this  interface.
                          This   specifies   the   maximum   time   in
                          Milliseconds to wait for acknowledgment of a
                          PDU."
                  ::= { lapbDefEntry 12 }

          lapbDefT2AckDelayTimer          OBJECT-TYPE
                  SYNTAX  INTEGER (0..1800000)
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 8885 Table 3, Name: Reply delay timer
                  DESCRIPTION
                          "The default T2 timer  for  this  interface.
                          This   specifies   the   maximum   time   in
                          Milliseconds  to  wait  before  sending   an
                          acknowledgment for a sequenced PDU.  A value
                          of zero means there  will  be  no  delay  in
                          acknowledgement generation."
                  ::= { lapbDefEntry 13 }

          lapbDefPortNumber OBJECT-TYPE
                  SYNTAX  OCTET STRING (SIZE (0..255))
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 8885 Table 3, Name: Port number
                  DESCRIPTION
                          "The port number assigned for this link.   A
                          zero  length  string indicates no local port
                          number identifier has been assigned."
                  ::= { lapbDefEntry 14 }

          lapbDefUserDataSubfield OBJECT-TYPE
                  SYNTAX  OCTET STRING (SIZE (0..8206))
                  ACCESS  read-write
                  STATUS  mandatory
                  -- See ISO 8885 section 4.3
                  DESCRIPTION
                          "A  user  data  subfield,  if  any,  to   be
                          transmitted  in an XID frame.  A zero length
                          frame indicates no user  data  subfield  has
                          been  assigned.   The  octet  string  should
                          include both the User  data  identifier  and





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                  User  data  field  as shown in Figures 1 and
                          4."
                  ::= { lapbDefEntry 15 }



          -- The following describes some of the MIB-II interface
          -- objects and their relationship with the objects in this
          -- MIB extension.

          -- ifDescr:  describes the interface.   It should include
          -- identification information for the physical line and a
          -- description of the network.  For connections to PDNs,
          -- it should name the PDN.

          -- ifMtu: the maximum number of bytes an upper layer can pass
          -- to this interface as a single frame.

          -- ifSpeed:

          -- ifAdminStatus:

          -- ifOperStatus:

          -- ifLastChange: the last time the state of the interface
          -- changed.  A reset is considered an instantaneous change to
          -- the ndm state and back to abm or abme.  This will be the
          -- last time that lapbFlowChangeReason and lapbFlowChanges
          -- changed.

          -- ifInOctets: contains the number of information bytes
          -- received from the peer LAPB.

          -- ifInUcastPkts: contains the number of PDUs delivered by
          -- this interface to a higher layer interface.

          -- ifInDiscards: contains the total number of received
          -- packets discarded because of local conditions
          -- (such as lack of buffering).

          -- ifInErrors: contains the number of received packets that
          -- contained errors (such as out of sequence,
          -- invalid control field, etc);

          -- ifInUnknownProtos: contains the number of received packets





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          -- that were correct but were dropped due to unknown
          -- destinations.

          -- ifOutOctets: number of information octets sent to peer.

          -- ifOutUcastPkts: number of packets received from
          -- a higher layer for transmission to peer.

          -- ifOutDiscards: number of packets dropped due to conditions
          -- such as buffering etc.

          -- ifOutErrors: number of packet transmissions that failed
          -- due to errors.

          -- ifOutQLen: number of packets waiting to be transmitted.


          -- This MIB does not provide any support for:
          --      Multilink procedure (MLP) in ISO 7776 section 6
          --      LLC Pbit timer
          --      LLC REJ timer
          --      LLC Busy State Timer 7.8.1.4

          -- ###########################################################

          END
























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          7.  Acknowledgements

          This document was produced by the x25mib working group:

               Fred Baker, ACC
               Art Berggreen, ACC
               Frank Bieser
               Charles Carvalho, ACC
               Angela Chen, HP
               Chuck Davin, MIT
               Doug Geller, Data General
               Herve Goguely, LIR Corp
               David Gurevich,
               Richard Fox, Synoptics
               Steve Huston, Process Software Corporation
               Frank Kastenholz, Clearpoint
               Zbigniew Kiel
               Cheryl Krupezak, Georgia Tech
               Mats Lindstrom, Diab Data AB
               Andrew Malis, BBN
               Evan McGinnis, 3Com
               Gary (G.P.)Mussar, BNR
               Karen Quidley, Data General
               Randy Pafford, Data General
               Ragnar Paulson, The Software Group Limited
               Dave Perkins, Synoptics
               Walter Pinkarschewsky, DEC
               Paul S. Rarey, DHL Systems Inc.
               Jim Roche, Newbridge Research
               Philippe Roger, LIR Corp.
               Mike Shand, DEC
               Bob Stewart, Xyplex
               Tom Sullivan, Data General
               Rodney Thayer,  Sable Technology Corporation.
               Mark Therieau, Microcom
               Jane Thorn, Data General
               Dean Throop, Data General
               Mike Zendels, Data General

          In addition, the comments of the following individuals are
          also acknowledged:

               Keith McCloghrie







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          8.  References

          [1]  M.T. Rose and K. McCloghrie, "Structure and
               Identification of Management Information for TCP/IP-based
               internets", RFC 1155, Network Information Center, SRI
               International, Menlo Park, California, (May, 1990).

          [2]  K. McCloghrie and M.T. Rose, "Management Information Base
               for Network Management of TCP/IP-based internets", RFC
               1156, Network Information Center, SRI International,
               Menlo Park, California, (May, 1990).

          [3]  J.D. Case, M.S. Fedor, M.L. Schoffstall, and J.R. Davin,
               "Simple Network Management Protocol", RFC 1157, Network
               Information Center, SRI International, Menlo Park,
               California, (May, 1990).

          [4]  M.T. Rose, K. McCloghrie (editors), "Towards Concise MIB
               Definitions", RFC 1212, Network Information Center, SRI
               International, Menlo Park, California, (March, 1991)

          [5]  M.T. Rose (editor), "Management Information Base for
               Network Management of TCP/IP-based internets", RFC 1213.
               Network Information Center, SRI International, Menlo
               Park, California, (March, 1991).

          [6]  Information processing systems - Open Systems
               Interconnection - Specification of Abstract Syntax
               Notation One (ASN.1), International Organization for
               Standardization.  International Standard 8824, (December,
               1987).

          [7]  Information processing systems - Open Systems
               Interconnection - Specification of Basic Encoding Rules
               for Abstract Notation One (ASN.1), International
               Organization for Standardization.  International Standard
               8825, (December, 1987).

          [8]  B. Stewart (editor), "Definitions of Managed Objects for
               RS-232-like Hardware Devices", Internet Draft, Internet
               Engineering Task Force, (December, 1990)

          [9]  D. Throop (editor), "SNMP MIB extension for the Packet
               Layer of X.25", Internet Draft, Internet Engineering Task
               Force, (December, 1991).





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          [10] "Information processing systems - Data communication -
               High-level data link control procedure - Description of
               the X.25 LAPB-compatible DTE data link procedures",
               International Organization for Standardization,
               International Standard 7776, (December, 1986).

          [11] "Information technology - Telecommunications and
               information exchange between systems - High-level data
               link control (HDLC) procedures - General purpose XID
               frame information field contents and format",
               International Organization for Standardization,
               International Standard 8885.






































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          Table of Contents


          1 Status of this Memo ...................................    1
          1.1 Revision History ....................................    1
           February 1992 ..........................................    1
           October 1991 ...........................................    3
           June 1991 ..............................................    3
           April 1991 .............................................    3
          2 Abstract ..............................................    3
          3 The Network Management Framework ......................    5
          4 Objects ...............................................    5
          4.1 Format of Definitions ...............................    6
          5 Overview ..............................................    7
          5.1 Informal overview ...................................    7
          5.2 Formal overview .....................................    8
          6 Object Definitions ....................................    9
          7 Acknowledgements ......................................   27
          8 References ............................................   28































          D. Throop                                            [Page 30]