





Network Working Group                                      K. McCloghrie
Request for Comments: 1231                      Hughes LAN Systems, Inc.
                                                                  R. Fox
                                                         Synoptics, Inc.
                                                               E. Decker
                                                     cisco Systems, Inc.
                                                                May 1991


                       IEEE 802.5 Token Ring MIB

Status of this Memo

   This memo defines a MIB for 805.5 networks for use with the SNMP
   protocol.  This memo is a product of the Transmission Working Group
   of the Internet Engineering Task Force (IETF).  This RFC specifies an
   IAB standards track protocol for the Internet community, and requests
   discussion and suggestions for improvements.  Please refer to the
   current edition of the "IAB Official Protocol Standards" for the
   standardization state and status of this protocol.  Distribution of
   this memo is unlimited.

Table of Contents

   1. Abstract ..............................................    1
   2. The Network Management Framework.......................    2
   3. Objects ...............................................    2
   3.1 Format of Definitions ...............................     3
   4. Overview ..............................................    3
   4.1 Scope of Definitions ................................     3
   4.2 Textual Conventions .................................     3
   5. Definitions ...........................................    4
   6. Acknowledgements ......................................   21
   7. References ............................................   22
   8. Security Considerations................................   23
   9. Authors' Addresses.....................................   23

1.  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, this memo defines managed
   objects used for managing subnetworks which use the IEEE 802.5 Token
   Ring technology described in 802.5 Token Ring Access Method and
   Physical Layer Specifications, IEEE Standard 802.5-1989.






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2.  The Network Management Framework

   The Internet-standard Network Management Framework consists of three
   components.  They are:

      RFC 1155 which defines the SMI, the mechanisms used for describing
      and naming objects for the purpose of management.  RFC 1212
      defines a more concise description mechanism, which is wholly
      consistent with the SMI.

      RFC 1156 which defines MIB-I, the core set of managed objects for
      the Internet suite of protocols.  RFC 1213, defines MIB-II, an
      evolution of MIB-I based on implementation experience and new
      operational requirements.

      RFC 1157 which defines the SNMP, the protocol used for network
      access to managed objects.

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

3.  Objects

   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) [7]
   defined in the SMI.  In particular, each object has a name, a syntax,
   and an encoding.  The name is an object identifier, an
   administratively assigned name, which specifies an object type.  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 OBJECT
   DESCRIPTOR, to also refer to the object type.

   The syntax of an object type defines the abstract data structure
   corresponding to that object type.  The ASN.1 language is used for
   this purpose.  However, the SMI [3] purposely restricts the ASN.1
   constructs which may be used.  These restrictions are explicitly made
   for simplicity.

   The encoding of an object type is simply how that object type is
   represented using the object type's syntax.  Implicitly tied to the
   notion of an object type's syntax and encoding is how the object type
   is represented when being transmitted on the network.

   The SMI specifies the use of the basic encoding rules of ASN.1 [8],
   subject to the additional requirements imposed by the SNMP.




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3.1.  Format of Definitions

   Section 5 contains contains the specification of all object types
   contained in this MIB module.  The object types are defined using the
   conventions defined in the SMI, as amended by the extensions
   specified in [9,10].

4.  Overview

   This memo defines three tables: the 802.5 Interface Table, which
   contains state and parameter information which is specific to 802.5
   interfaces, the 802.5 Statistics Table, which contains 802.5
   interface statistics, and the 802.5 Timer Table, which contains the
   values of 802.5-defined timers. A managed system will have one entry
   in the 802.5 Interface Table and one entry in the 802.5 Statistics
   Table for each of its 802.5 interfaces.  Implementation of the 802.5
   Timer Table is optional.

   This memo also defines OBJECT IDENTIFIERs, some to identify 802.5
   tests, for use with the ifExtnsTestTable defined in [11], and some to
   identify Token Ring interface Chip Sets, for use with the
   ifExtnsChipSet object defined in [11].

4.1.  Scope of Definitions

   All objects defined in this memo are registered in a single subtree
   within the experimental namespace [3], and are for use with every
   interface which conforms to the IEEE 802.5 Token Ring Access Method
   and Physical Layer Specifications [10].  At present, this applies to
   interfaces for which the ifType variable in the Internet-standard MIB
   [4,6] has the value:

              iso88025-tokenRing(9)

   For these interfaces, the value of the ifSpecific variable in the
   MIB-II [6] has the OBJECT IDENTIFIER value:

               dot5    OBJECT IDENTIFIER ::= { experimental 4 }

   as defined below.

4.2.  Textual Conventions

   A new datatype, MacAddress, is introduced as a textual convention in
   this document.  This textual convention has NO effect on either the
   syntax nor the semantics of any managed object. Objects defined using
   this convention are always encoded by means of the rules that define
   their primitive type.  Hence, no changes to the SMI or the SNMP are



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   necessary to accommodate this textual convention which is adopted
   merely for the convenience of readers.

5.  Definitions


          RFC1231-MIB DEFINITIONS ::= BEGIN

          --                 IEEE 802.5 Token Ring MIB

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

          --  This MIB Module uses the extended OBJECT-TYPE macro as
          --  defined in [9].



          dot5    OBJECT IDENTIFIER ::= { experimental 4 }

          -- All representations of MAC addresses in this MIB Module
          -- use, as a textual convention (i.e. this convention does
          -- not affect their encoding), the data type:

          MacAddress ::= OCTET STRING (SIZE (6))    -- a 6 octet
                                                    -- address in the
                                                    -- "canonical" order
          -- defined by IEEE 802.1a, i.e., as if it were transmitted
          -- least significant bit first, even though 802.5 (in
          -- contrast to other 802.x protocols) requires MAC addresses
          -- to be transmitted most significant bit first.
          --
          -- 16-bit addresses, if needed, are represented by setting
          -- their upper 4 octets to all 0's, i.e., AAFF would be
          -- represented as 00000000AAFF.



          -- The Interface Table

          -- This table contains state and parameter information which
          -- is specific to 802.5 interfaces.  It is mandatory that
          -- systems having 802.5 interfaces implement this table in
          -- addition to the generic interfaces table [4,6] and its
          -- generic extensions [11].



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          dot5Table  OBJECT-TYPE
                     SYNTAX  SEQUENCE OF Dot5Entry
                     ACCESS  not-accessible
                     STATUS  mandatory
                     DESCRIPTION
                             "This table contains Token Ring interface
                             parameters and state variables, one entry
                             per 802.5 interface."
                     ::= { dot5 1 }

          dot5Entry  OBJECT-TYPE
                     SYNTAX  Dot5Entry
                     ACCESS  not-accessible
                     STATUS  mandatory
                     DESCRIPTION
                             "A list of Token Ring status and parameter
                              values for an 802.5 interface."
                     INDEX   { dot5IfIndex }
                     ::= { dot5Table 1 }

          Dot5Entry
              ::= SEQUENCE {
                      dot5IfIndex
                          INTEGER,
                      dot5Commands
                          INTEGER,
                      dot5RingStatus
                          INTEGER,
                      dot5RingState
                          INTEGER,
                      dot5RingOpenStatus
                          INTEGER,
                      dot5RingSpeed
                          INTEGER,
                      dot5UpStream
                          MacAddress,
                      dot5ActMonParticipate
                          INTEGER,
                      dot5Functional
                          MacAddress
                  }

          dot5IfIndex  OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The value of this object identifies the



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                              802.5 interface for which this entry
                              contains management information.  The
                              value of this object for a particular
                              interface has the same value as the
                              ifIndex object, defined in [4,6],
                              for the same interface."
                     ::= { dot5Entry 1 }

          dot5Commands  OBJECT-TYPE
                     SYNTAX  INTEGER {
                                   no-op(1),
                                   open(2),
                                   reset(3),
                                   close(4)
                             }
                     ACCESS  read-write
                     STATUS  mandatory
                     DESCRIPTION
                             "When this object is set to the value of
                              open(2), the station should go into the
                              open state.  The progress and success of
                              the open is given by the values of the
                              objects dot5RingState and
                              dot5RingOpenStatus.
                                  When this object is set to the value
                              of reset(3), then the station should do
                              a reset.  On a reset, all MIB counters
                              should retain their values, if possible.
                              Other side affects are dependent on the
                              hardware chip set.
                                  When this object is set to the value
                              of close(4), the station should go into
                              the stopped state by removing itself
                              from the ring.
                                  Setting this object to a value of
                              no-op(1) has no effect.
                                  When read, this object always has a
                              value of no-op(1)."
                     ::= { dot5Entry 2 }

          dot5RingStatus OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The current interface status which can
                             be used to diagnose fluctuating problems
                             that can occur on token rings, after a



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                             station has successfully been added to
                             the ring.
                                Before an open is completed, this
                             object has the value for the 'no status'
                             condition.  The dot5RingState and
                             dot5RingOpenStatus objects provide for
                             debugging problems when the station
                             can not even enter the ring.
                                 The object's value is a sum of
                             values, one for each currently applicable
                             condition.  The following values are
                             defined for various conditions:

                                     0 = No Problems detected
                                    32 = Ring Recovery
                                    64 = Single Station
                                   256 = Remove Received
                                   512 = reserved
                                  1024 = Auto-Removal Error
                                  2048 = Lobe Wire Fault
                                  4096 = Transmit Beacon
                                  8192 = Soft Error
                                 16384 = Hard Error
                                 32768 = Signal Loss
                                131072 = no status, open not completed."
                     ::= { dot5Entry 3 }

          dot5RingState  OBJECT-TYPE
                     SYNTAX  INTEGER {
                                   opened(1),
                                   closed(2),
                                   opening(3),
                                   closing(4),
                                   openFailure(5),
                                   ringFailure(6)
                             }
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The current interface state with respect
                             to entering or leaving the ring."
                     ::= { dot5Entry 4 }

          dot5RingOpenStatus  OBJECT-TYPE
                     SYNTAX  INTEGER {
                                   noOpen(1),     -- no open attempted
                                   badParam(2),
                                   lobeFailed(3),



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                                   signalLoss(4),
                                   insertionTimeout(5),
                                   ringFailed(6),
                                   beaconing(7),
                                   duplicateMAC(8),
                                   requestFailed(9),
                                   removeReceived(10),
                                   open(11)      -- last open successful
                             }
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "This object indicates the success, or the
                             reason for failure, of the station's most
                             recent attempt to enter the ring."
                     ::= { dot5Entry 5 }

          dot5RingSpeed  OBJECT-TYPE
                     SYNTAX  INTEGER {
                                   unknown(1),
                                   oneMegabit(2),
                                   fourMegabit(3),
                                   sixteenMegabit(4)
                             }
                     ACCESS  read-write
                     STATUS  mandatory
                     DESCRIPTION
                             "The ring's bandwidth."
                     ::= { dot5Entry 6 }

          dot5UpStream  OBJECT-TYPE
                     SYNTAX  MacAddress
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The MAC-address of the up stream neighbor
                              station in the ring."
                     ::= { dot5Entry 7 }

          dot5ActMonParticipate OBJECT-TYPE
                     SYNTAX  INTEGER {
                                   true(1),
                                   false(2)
                             }
                     ACCESS  read-write
                     STATUS  mandatory
                     DESCRIPTION
                             "If this object has a value of true(1) then



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                             this interface will participate in the
                             active monitor selection process.  If the
                             value is false(2) then it will not.
                             Setting this object might not have an
                             effect until the next time the interface
                             is opened."
                     ::= { dot5Entry 8 }

          dot5Functional OBJECT-TYPE
                     SYNTAX  MacAddress
                     ACCESS  read-write
                     STATUS  mandatory
                     DESCRIPTION
                             "The bit mask of all Token Ring functional
                             addresses for which this interface will
                             accept frames."
                     ::= { dot5Entry 9 }



          --   The Statistics Table

          -- This table contains statistics and error counter which are
          -- specific to 802.5 interfaces.  It is mandatory that systems
          -- having 802.5 interfaces implement this table.

          dot5StatsTable  OBJECT-TYPE
                     SYNTAX  SEQUENCE OF Dot5StatsEntry
                     ACCESS  not-accessible
                     STATUS  mandatory
                     DESCRIPTION
                             "A table containing Token Ring statistics,
                             one entry per 802.5 interface.
                                 All the statistics are defined using
                             the syntax Counter as 32-bit wrap around
                             counters.  Thus, if an interface's
                             hardware maintains these statistics in
                             16-bit counters, then the agent must read
                             the hardware's counters frequently enough
                             to prevent loss of significance, in order
                             to maintain 32-bit counters in software."
                     ::= { dot5 2 }

          dot5StatsEntry  OBJECT-TYPE
                     SYNTAX  Dot5StatsEntry
                     ACCESS  not-accessible
                     STATUS  mandatory
                     DESCRIPTION



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                             "An entry contains the 802.5 statistics
                              for a particular interface."
                     INDEX   { dot5StatsIfIndex }
                     ::= { dot5StatsTable 1 }

          Dot5StatsEntry
              ::= SEQUENCE {
                      dot5StatsIfIndex
                          INTEGER,
                      dot5StatsLineErrors
                          Counter,
                      dot5StatsBurstErrors
                          Counter,
                      dot5StatsACErrors
                          Counter,
                      dot5StatsAbortTransErrors
                          Counter,
                      dot5StatsInternalErrors
                          Counter,
                      dot5StatsLostFrameErrors
                          Counter,
                      dot5StatsReceiveCongestions
                          Counter,
                      dot5StatsFrameCopiedErrors
                          Counter,
                      dot5StatsTokenErrors
                          Counter,
                      dot5StatsSoftErrors
                          Counter,
                      dot5StatsHardErrors
                          Counter,
                      dot5StatsSignalLoss
                          Counter,
                      dot5StatsTransmitBeacons
                          Counter,
                      dot5StatsRecoverys
                          Counter,
                      dot5StatsLobeWires
                          Counter,
                      dot5StatsRemoves
                          Counter,
                      dot5StatsSingles
                          Counter,
                      dot5StatsFreqErrors
                          Counter
                  }





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          dot5StatsIfIndex  OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The value of this object identifies the
                             802.5 interface for which this entry
                             contains management information.  The
                             value of this object for a particular
                             interface has the same value as the
                             ifIndex object, defined in [4,6], for
                             the same interface."
                     ::= { dot5StatsEntry 1 }

          dot5StatsLineErrors OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "This counter is incremented when a frame
                             or token is copied or repeated by a
                             station, the E bit is zero in the frame
                             or token and one of the following
                             conditions exists: 1) there is a
                             non-data bit (J or K bit) between the SD
                             and the ED of the frame or token, or
                             2) there is an FCS error in the frame."
                     ::= { dot5StatsEntry 2 }

          dot5StatsBurstErrors OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "This counter is incremented when a station
                             detects the absence of transitions for five
                             half-bit timers (burst-five error)."
                     ::= { dot5StatsEntry 3 }

          dot5StatsACErrors OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "This counter is incremented when a station
                             receives an AMP or SMP frame in which A is
                             equal to C is equal to 0, and then receives
                             another SMP frame with A is equal to C is



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                             equal to 0 without first receiving an AMP
                             frame. It denotes a station that cannot set
                             the AC bits properly."
                     ::= { dot5StatsEntry 4 }

          dot5StatsAbortTransErrors OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "This counter is incremented when a station
                             transmits an abort delimiter while
                             transmitting."
                     ::= { dot5StatsEntry 5 }

          dot5StatsInternalErrors OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "This counter is incremented when a station
                             recognizes an internal error."
                     ::= { dot5StatsEntry 6 }

          dot5StatsLostFrameErrors OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "This counter is incremented when a station
                             is transmitting and its TRR timer expires.
                             This condition denotes a condition where a
                             transmitting station in strip mode does not
                             receive the trailer of the frame before the
                             TRR timer goes off."
                     ::= { dot5StatsEntry 7 }

          dot5StatsReceiveCongestions OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "This counter is incremented when a station
                             recognizes a frame addressed to its
                             specific address, but has no available
                             buffer space indicating that the station
                             is congested."
                     ::= { dot5StatsEntry 8 }



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          dot5StatsFrameCopiedErrors OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "This counter is incremented when a station
                             recognizes a frame addressed to its
                             specific address and detects that the FS
                             field A bits are set to 1 indicating a
                             possible line hit or duplicate address."
                     ::= { dot5StatsEntry 9 }

          dot5StatsTokenErrors OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "This counter is incremented when a station
                             acting as the active monitor recognizes an
                             error condition that needs a token
                             transmitted."
                     ::= { dot5StatsEntry 10 }

          dot5StatsSoftErrors OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The number of Soft Errors the interface
                             has detected. It directly corresponds to
                             the number of Report Error MAC frames
                             that this interface has transmitted.
                             Soft Errors are those which are
                             recoverable by the MAC layer protocols."
                     ::= { dot5StatsEntry 11 }

          dot5StatsHardErrors OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The number of times this interface has
                             detected an immediately recoverable
                             fatal error.  It denotes the number of
                             times this interface is either
                             transmitting or receiving beacon MAC
                             frames."
                     ::= { dot5StatsEntry 12 }



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          dot5StatsSignalLoss OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The number of times this interface has
                             detected the loss of signal condition from
                             the ring."
                     ::= { dot5StatsEntry 13 }

          dot5StatsTransmitBeacons OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The number of times this interface has
                             transmitted a beacon frame."
                     ::= { dot5StatsEntry 14 }

          dot5StatsRecoverys OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The number of Claim Token MAC frames
                             received or transmitted after the interface
                             has received a Ring Purge MAC frame.  This
                             counter signifies the number of times the
                             ring has been purged and is being recovered
                             back into a normal operating state."
                     ::= { dot5StatsEntry 15 }

          dot5StatsLobeWires OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The number of times the interface has
                             detected an open or short circuit in the
                             lobe data path.  The adapter will be closed
                             and dot5RingState will signify this
                             condition."
                     ::= { dot5StatsEntry 16 }

          dot5StatsRemoves OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory



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                     DESCRIPTION
                             "The number of times the interface has
                             received a Remove Ring Station MAC frame
                             request.  When this frame is received
                             the interface will enter the close state
                             and dot5RingState will signify this
                             condition."
                     ::= { dot5StatsEntry 17 }

          dot5StatsSingles OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The number of times the interface has
                             sensed that it is the only station on the
                             ring.  This will happen if the interface
                             is the first one up on a ring, or if
                             there is a hardware problem."
                     ::= { dot5StatsEntry 18 }

          dot5StatsFreqErrors OBJECT-TYPE
                     SYNTAX  Counter
                     ACCESS  read-only
                     STATUS  optional
                     DESCRIPTION
                             "The number of times the interface has
                             detected that the frequency of the
                             incoming signal differs from the expected
                             frequency by more than that specified by
                             the IEEE 802.5 standard, see chapter 7
                             in [10]."
                     ::= { dot5StatsEntry 19 }


          -- The Timer Table

          -- This group contains the values of the timers defined in
          -- [10] for 802.5 interfaces.  It is optional that systems
          -- having 802.5 interfaces implement this group.

          dot5TimerTable  OBJECT-TYPE
                     SYNTAX  SEQUENCE OF Dot5TimerEntry
                     ACCESS  not-accessible
                     STATUS  mandatory
                     DESCRIPTION
                             "This table contains Token Ring interface
                             timer values, one entry per 802.5



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                             interface."
                     ::= { dot5 5 }

          dot5TimerEntry  OBJECT-TYPE
                     SYNTAX  Dot5TimerEntry
                     ACCESS  not-accessible
                     STATUS  mandatory
                     DESCRIPTION
                             "A list of Token Ring timer values for an
                             802.5 interface."
                     INDEX   { dot5TimerIfIndex }
                     ::= { dot5TimerTable 1 }

          Dot5TimerEntry
              ::= SEQUENCE {
                     dot5TimerIfIndex
                         INTEGER,
                     dot5TimerReturnRepeat
                         INTEGER,
                     dot5TimerHolding
                         INTEGER,
                     dot5TimerQueuePDU
                         INTEGER,
                     dot5TimerValidTransmit
                         INTEGER,
                     dot5TimerNoToken
                         INTEGER,
                     dot5TimerActiveMon
                         INTEGER,
                     dot5TimerStandbyMon
                         INTEGER,
                     dot5TimerErrorReport
                         INTEGER,
                     dot5TimerBeaconTransmit
                         INTEGER,
                     dot5TimerBeaconReceive
                         INTEGER
                 }

          dot5TimerIfIndex  OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The value of this object identifies the
                              802.5 interface for which this entry
                              contains timer values.  The value of
                              this object for a particular interface



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                              has the same value as the ifIndex
                              object, defined in [4,6], for the same
                              interface."
                     ::= { dot5TimerEntry 1 }

          dot5TimerReturnRepeat  OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The time-out value used to ensure the
                             interface will return to Repeat State, in
                             units of 100 micro-seconds.  The value
                             should be greater than the maximum ring
                             latency.
                                 Implementors are encouraged to provide
                             read-write access to this object if that is
                             possible/useful in their system, but giving
                             due consideration to the dangers of
                             write-able timers."
                     ::= { dot5TimerEntry 2 }

          dot5TimerHolding  OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "Maximum period of time a station is
                             permitted to transmit frames after capturing
                             a token, in units of 100 micro-seconds.
                                 Implementors are encouraged to provide
                             read-write access to this object if that is
                             possible/useful in their system, but giving
                             due consideration to the dangers of
                             write-able timers."
                     ::= { dot5TimerEntry 3 }

          dot5TimerQueuePDU  OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The time-out value for enqueuing of an SMP
                             PDU after reception of an AMP or SMP
                             frame in which the A and C bits were
                             equal to 0, in units of 100
                             micro-seconds.
                                 Implementors are encouraged to provide



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                             read-write access to this object if that is
                             possible/useful in their system, but giving
                             due consideration to the dangers of
                             write-able timers."
                     ::= { dot5TimerEntry 4 }

          dot5TimerValidTransmit OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The time-out value used by the active
                             monitor to detect the absence of valid
                             transmissions, in units of 100
                             micro-seconds.
                                 Implementors are encouraged to provide
                             read-write access to this object if that is
                             possible/useful in their system, but giving
                             due consideration to the dangers of
                             write-able timers."
                     ::= { dot5TimerEntry 5 }

          dot5TimerNoToken  OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The time-out value used to recover from
                             various-related error situations [9].
                             If N is the maximum number of stations on
                             the ring, the value of this timer is
                             normally:
                             dot5TimerReturnRepeat + N*dot5TimerHolding.
                                 Implementors are encouraged to provide
                             read-write access to this object if that is
                             possible/useful in their system, but giving
                             due consideration to the dangers of
                             write-able timers."
                     ::= { dot5TimerEntry 6 }

          dot5TimerActiveMon  OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The time-out value used by the active
                             monitor to stimulate the enqueuing of an
                             AMP PDU for transmission, in units of



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                             100 micro-seconds.
                                 Implementors are encouraged to provide
                             read-write access to this object if that is
                             possible/useful in their system, but giving
                             due consideration to the dangers of
                             write-able timers."
                     ::= { dot5TimerEntry 7 }

          dot5TimerStandbyMon  OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The time-out value used by the stand-by
                             monitors to ensure that there is an active
                             monitor on the ring and to detect a
                             continuous stream of tokens, in units of
                             100 micro-seconds.
                                 Implementors are encouraged to provide
                             read-write access to this object if that is
                             possible/useful in their system, but giving
                             due consideration to the dangers of
                             write-able timers."
                     ::= { dot5TimerEntry 8 }

          dot5TimerErrorReport  OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The time-out value which determines how
                             often a station shall send a Report Error
                             MAC frame to report its error counters,
                             in units of 100 micro-seconds.
                                 Implementors are encouraged to provide
                             read-write access to this object if that is
                             possible/useful in their system, but giving
                             due consideration to the dangers of
                             write-able timers."
                     ::= { dot5TimerEntry 9 }

          dot5TimerBeaconTransmit  OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The time-out value which determines how
                             long a station shall remain in the state



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                             of transmitting Beacon frames before
                             entering the Bypass state, in units of
                             100 micro-seconds.
                                 Implementors are encouraged to provide
                             read-write access to this object if that is
                             possible/useful in their system, but giving
                             due consideration to the dangers of
                             write-able timers."
                     ::= { dot5TimerEntry 10 }

          dot5TimerBeaconReceive  OBJECT-TYPE
                     SYNTAX  INTEGER
                     ACCESS  read-only
                     STATUS  mandatory
                     DESCRIPTION
                             "The time-out value which determines how
                             long a station shall receive Beacon
                             frames from its downstream neighbor
                             before entering the Bypass state, in
                             units of 100 micro-seconds.
                                 Implementors are encouraged to provide
                             read-write access to this object if that is
                             possible/useful in their system, but giving
                             due consideration to the dangers of
                             write-able timers."
                     ::= { dot5TimerEntry 11 }


          --                      802.5 Interface Tests

          dot5Tests         OBJECT IDENTIFIER ::= { dot5 3 }

          -- The extensions to the interfaces table proposed in [11]
          -- define a table object, ifExtnsTestTable, through which a
          -- network manager can instruct an agent to test an interface
          -- for various faults.  A test to be performed is identified
          -- (as the value of ifExtnsTestType) via an OBJECT IDENTIFIER.
          --
          -- The Full-Duplex Loop Back Test is a common test, defined
          -- in [11] as:
          --
          --    testFullDuplexLoopBack
          --
          -- Invoking this test on a 802.5 interface causes the
          -- interface to check the path from memory through the
          -- chip set's internal logic and back to memory, thus
          -- checking the proper functioning of the systems's
          -- interface to the chip set.



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          -- The Insert Function test is defined by:

          testInsertFunc    OBJECT IDENTIFIER ::= { dot5Tests 1 }

          -- Invoking this test causes the station to test the insert
          -- ring logic of the hardware if the station's lobe media
          -- cable is connected to a wiring concentrator.  Note that
          -- this command inserts the station into the network, and
          -- thus, could cause problems if the station is connected
          -- to a operational network.

          --                 802.5 Hardware Chip Sets

          dot5ChipSets   OBJECT IDENTIFIER ::= { dot5 4 }

          -- The extensions to the interfaces table proposed in [11]
          -- define an object, ifExtnsChipSet, with the syntax of
          -- OBJECT IDENTIFIER, to identify the hardware chip set in
          -- use by an interface.  That definition specifies just
          -- one applicable object identifier:
          --
          --    unknownChipSet
          --
          -- for use as the value of ifExtnsChipSet when the specific
          -- chip set is unknown.
          --
          -- This MIB defines the following for use as values of
          -- ifExtnsChipSet:

             -- IBM 16/4 Mb/s
          chipSetIBM16       OBJECT IDENTIFIER ::= { dot5ChipSets 1 }

             -- TI 4Mb/s
          chipSetTItms380    OBJECT IDENTIFIER ::= { dot5ChipSets 2 }

             -- TI 16/4 Mb/s
          chipSetTItms380c16 OBJECT IDENTIFIER ::= { dot5ChipSets 3 }

          END

6.  Acknowledgements

   This document was produced under the auspices of the IETF's
   Transmission Working Group.  The comments of the following
   individuals are acknowledged:






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RFC 1231                     IEEE 802.5 MIB                     May 1991


         Tom Benkart, Advanced Computer Communications
         Stan Froyd, Advanced Computer Communications
         Marshall T. Rose, Performance Systems International, Inc.

7.  References

   [1] Cerf, V., "IAB Recommendations for the Development of Internet
       Network Management Standards", RFC 1052, NRI, April 1988.

   [2] Cerf, V., "Report of the Second Ad Hoc Network Management Review
       Group", RFC 1109, NRI, August 1989.

   [3] Rose M., and K. McCloghrie, "Structure and Identification of
       Management Information for TCP/IP-based internets", RFC 1155,
       Performance Systems International, Hughes LAN Systems, May 1990.

   [4] McCloghrie K., and M. Rose, "Management Information Base for
       Network Management of TCP/IP-based internets", RFC 1156, Hughes
       LAN Systems, Performance Systems International, May 1990.

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

   [6] McCloghrie K., and M. Rose, Editors, "Management Information Base
       for Network Management of TCP/IP-based internets", RFC 1213,
       Performance Systems International, March 1991.

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

   [8] 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.

   [9] Rose, M., and K. McCloghrie, Editors, "Concise MIB Definitions",
       RFC 1212, Performance Systems International, Hughes LAN Systems,
       March 1991.

  [10] Token Ring Access Method and Physical Layer Specifications,
       Institute of Electrical and Electronic Engineers, IEEE Standard
       802.5-1989, 1989.





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  [11] McCloghrie, K., Editor, "Extensions to the Generic-Interface
       MIB", RFC 1229, Hughes LAN Systems, May 1991.

8.  Security Considerations

   Security issues are not discussed in this memo.

9.  Authors' Addresses

   Keith McCloghrie
   Hughes LAN Systems, Inc.
   1225 Charleston Road
   Mountain View, CA 94043

   Phone: (415) 966-7934
   EMail: kzm@hls.com


   Richard Fox
   Synoptics, Inc.
   4401 Great America Pkwy
   PO Box 58185
   Santa Clara, Cal. 95052

   Phone: (408) 764-1372
   EMail: rfox@synoptics.com


   Eric Decker
   cisco Systems, Inc.
   1525 O'Brien Dr.
   Menlo Park, CA 94025

   Phone: (415) 688-8241
   EMail: cire@cisco.com
















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