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RFC 2495

 
 
 

Definitions of Managed Objects for the DS1, E1, DS2 and E2 Interface Types

Part 3 of 3, p. 55 to 75
Prev RFC Part

 


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     Dsx1FracEntry ::=
         SEQUENCE {
             dsx1FracIndex        INTEGER,
             dsx1FracNumber       INTEGER,
             dsx1FracIfIndex      INTEGER
         }


     dsx1FracIndex OBJECT-TYPE
         SYNTAX  INTEGER (1..'7fffffff'h)
         MAX-ACCESS  read-only
         STATUS  deprecated
         DESCRIPTION
            "The index value which uniquely identifies  the
            DS1  interface  to which this entry is applicable
            The interface identified by a  particular
            value  of  this  index is the same interface as
            identified by the same value  an  dsx1LineIndex
            object instance."
        ::= { dsx1FracEntry 1 }

     dsx1FracNumber OBJECT-TYPE
         SYNTAX  INTEGER (1..31)
         MAX-ACCESS  read-only
         STATUS  deprecated
         DESCRIPTION
            "The channel number for this entry."
        ::= { dsx1FracEntry 2 }

     dsx1FracIfIndex OBJECT-TYPE
         SYNTAX  INTEGER (1..'7fffffff'h)
         MAX-ACCESS  read-write
         STATUS  deprecated
         DESCRIPTION
            "An index value that uniquely identifies an
            interface.  The interface identified by a particular
            value of this index is the same  interface
            as  identified by the same value an ifIndex
            object instance. If no interface is currently using
            a channel, the value should be zero.  If a
            single interface occupies more  than  one  time
            slot,  that ifIndex value will be found in multiple
            time slots."
        ::= { dsx1FracEntry 3 }

      -- Ds1 TRAPS

     ds1Traps OBJECT IDENTIFIER ::= { ds1 15 }

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     dsx1LineStatusChange NOTIFICATION-TYPE
         OBJECTS { dsx1LineStatus,
                   dsx1LineStatusLastChange }
         STATUS  current
         DESCRIPTION
                 "A dsx1LineStatusChange trap is sent when the
                 value of an instance dsx1LineStatus changes. It
                 can be utilized by an NMS to trigger polls.  When
                 the line status change results from a higher level
                 line status change (i.e. ds3), then no traps for
                 the ds1 are sent."
          ::= { ds1Traps 0 1 }

     -- conformance information
     ds1Conformance OBJECT IDENTIFIER ::= { ds1 14 }

     ds1Groups      OBJECT IDENTIFIER ::= { ds1Conformance 1 }
     ds1Compliances OBJECT IDENTIFIER ::= { ds1Conformance 2 }



     -- compliance statements

     ds1Compliance MODULE-COMPLIANCE
         STATUS  current
         DESCRIPTION
                 "The compliance statement for T1 and E1
                 interfaces."
         MODULE  -- this module
             MANDATORY-GROUPS { ds1NearEndConfigGroup,
                                ds1NearEndStatisticsGroup }

             GROUP       ds1FarEndGroup
             DESCRIPTION
                 "Implementation of this group is optional for all
                 systems that attach to a DS1 Interface."

             GROUP       ds1NearEndOptionalConfigGroup
             DESCRIPTION
                 "Implementation of this group is optional for all
                 systems that attach to a DS1 Interface."

             GROUP       ds1DS2Group
             DESCRIPTION
                 "Implementation of this group is mandatory for all
                 systems that attach to a DS2 Interface."

             GROUP       ds1TransStatsGroup

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             DESCRIPTION
                 "This group is the set of statistics appropriate
                 for all systems which attach to a DS1 Interface
                 running transparent or unFramed lineType."


             GROUP       ds1ChanMappingGroup
             DESCRIPTION
                 "This group is the set of objects for mapping a
                 DS3 Channel (ds1ChannelNumber) to ifIndex.

                 Implementation of this group is mandatory for
                 systems which support the channelization of DS3s
                 into DS1s."

             OBJECT dsx1LineType
             MIN-ACCESS read-only
             DESCRIPTION
                 "The ability to set the line type is not
                 required."

             OBJECT dsx1LineCoding
             MIN-ACCESS read-only
             DESCRIPTION
                 "The ability to set the line coding is not
                 required."

             OBJECT dsx1SendCode
             MIN-ACCESS read-only
             DESCRIPTION
                 "The ability to set the send code is not
                 required."

             OBJECT dsx1LoopbackConfig
             MIN-ACCESS read-only
             DESCRIPTION
                 "The ability to set loopbacks is not required."

             OBJECT dsx1SignalMode
             MIN-ACCESS read-only
             DESCRIPTION
                 "The ability to set the signal mode is not
                 required."

             OBJECT dsx1TransmitClockSource
             MIN-ACCESS read-only
             DESCRIPTION
                 "The ability to set the transmit clock source is

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                 not required."

             OBJECT dsx1Fdl
             MIN-ACCESS read-only
             DESCRIPTION
                 "The ability to set the FDL is not required."

             OBJECT dsx1LineLength
             MIN-ACCESS read-only
             DESCRIPTION
                 "The ability to set the line length is not
                 required."

             OBJECT dsx1Channelization
             MIN-ACCESS read-only
             DESCRIPTION
                 "The ability to set the channelization is not
                 required."
         ::= { ds1Compliances 1 }

     ds1MibT1PriCompliance MODULE-COMPLIANCE
         STATUS current
         DESCRIPTION
                 "Compliance statement for using this MIB for ISDN
                 Primary Rate interfaces on T1 lines."
         MODULE
             MANDATORY-GROUPS { ds1NearEndConfigGroup,
                                ds1NearEndStatisticsGroup }
             OBJECT dsx1LineType
                 SYNTAX INTEGER {
                     dsx1ESF(2)   -- Intl Spec would be G704(2)
                                  -- or I.431(4)
                 }
                 MIN-ACCESS read-only
                 DESCRIPTION
                     "Line type for T1 ISDN Primary Rate
                      interfaces."

             OBJECT dsx1LineCoding
                 SYNTAX INTEGER {
                     dsx1B8ZS(2)
                 }
                 MIN-ACCESS read-only
                 DESCRIPTION
                     "Type of Zero Code Suppression for
                      T1 ISDN Primary Rate interfaces."

             OBJECT dsx1SignalMode

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                 SYNTAX INTEGER {
                     none(1), -- if there is no signaling channel
                     messageOriented(4)
                 }
                 MIN-ACCESS read-only
                 DESCRIPTION
                     "Possible signaling modes for
                      T1 ISDN Primary Rate interfaces."

             OBJECT dsx1TransmitClockSource
                 SYNTAX INTEGER {
                     loopTiming(1)
                 }
                 MIN-ACCESS read-only
                 DESCRIPTION
                     "The transmit clock is derived from
                      received clock on ISDN Primary Rate
                      interfaces."

             OBJECT dsx1Fdl
                 MIN-ACCESS read-only
                 DESCRIPTION
                     "Facilities Data Link usage on T1 ISDN
                      Primary Rate interfaces.
                      Note: Eventually dsx1Att-54016(4) is to be
                            used here since the line type is ESF."

             OBJECT dsx1Channelization
                 MIN-ACCESS read-only
                 DESCRIPTION
                     "The ability to set the channelization
                      is not required."
         ::= { ds1Compliances 2 }


     ds1MibE1PriCompliance MODULE-COMPLIANCE
         STATUS current
         DESCRIPTION
                 "Compliance statement for using this MIB for ISDN
                 Primary Rate interfaces on E1 lines."
         MODULE
             MANDATORY-GROUPS { ds1NearEndConfigGroup,
                                ds1NearEndStatisticsGroup }
             OBJECT dsx1LineType
                 SYNTAX INTEGER {
                     dsx1E1CRC(5)
                 }
                 MIN-ACCESS read-only

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                 DESCRIPTION
                     "Line type for E1 ISDN Primary Rate
                      interfaces."

             OBJECT dsx1LineCoding
                 SYNTAX INTEGER {
                     dsx1HDB3(3)
                 }
                 MIN-ACCESS read-only
                 DESCRIPTION
                     "Type of Zero Code Suppression for
                      E1 ISDN Primary Rate interfaces."

             OBJECT dsx1SignalMode
                 SYNTAX INTEGER {
                     messageOriented(4)
                 }
                 MIN-ACCESS read-only
                 DESCRIPTION
                     "Signaling on E1 ISDN Primary Rate interfaces
                      is always message oriented."

             OBJECT dsx1TransmitClockSource
                 SYNTAX INTEGER {
                     loopTiming(1)
                 }
                 MIN-ACCESS read-only
                 DESCRIPTION
                     "The transmit clock is derived from received
                      clock on ISDN Primary Rate interfaces."

             OBJECT dsx1Fdl
                 MIN-ACCESS read-only
                 DESCRIPTION
                     "Facilities Data Link usage on E1 ISDN
                      Primary Rate interfaces.
                      Note: There is a 'M-Channel' in E1,
                            using National Bit Sa4 (G704,
                            Table 4a). It is used to implement
                            management features between ET
                            and NT.  This is different to
                            FDL in T1, which is used to carry
                            control signals and performance
                            data.  In E1, control and status
                            signals are carried using National
                            Bits Sa5, Sa6 and A (RAI Ind.).
                      This indicates that only the other(1) or
                      eventually the dsx1Fdl-none(8) bits should

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                      be set in this object for E1 PRI."

             OBJECT dsx1Channelization
                 MIN-ACCESS read-only
                 DESCRIPTION
                 "The ability to set the channelization is not
                 required."
         ::= { ds1Compliances 3 }


     ds1Ds2Compliance MODULE-COMPLIANCE
         STATUS current
         DESCRIPTION
                 "Compliance statement for using this MIB for DS2
                 interfaces."
         MODULE
             MANDATORY-GROUPS { ds1DS2Group }

             OBJECT dsx1Channelization
                 MIN-ACCESS read-only
                 DESCRIPTION
                 "The ability to set the channelization is not
                 required."
         ::= { ds1Compliances 4 }

     -- units of conformance

     ds1NearEndConfigGroup  OBJECT-GROUP
         OBJECTS { dsx1LineIndex,
                   dsx1TimeElapsed,
                   dsx1ValidIntervals,
                   dsx1LineType,
                   dsx1LineCoding,
                   dsx1SendCode,
                   dsx1CircuitIdentifier,
                   dsx1LoopbackConfig,
                   dsx1LineStatus,
                   dsx1SignalMode,
                   dsx1TransmitClockSource,
                   dsx1Fdl,
                   dsx1InvalidIntervals,
                   dsx1LineLength,
                   dsx1LoopbackStatus,
                   dsx1Ds1ChannelNumber,
                   dsx1Channelization }
         STATUS  current
         DESCRIPTION
                 "A collection of objects providing configuration

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                 information applicable to all DS1 interfaces."
         ::= { ds1Groups 1 }

     ds1NearEndStatisticsGroup OBJECT-GROUP
         OBJECTS { dsx1CurrentIndex,
                   dsx1CurrentESs,
                   dsx1CurrentSESs,
                   dsx1CurrentSEFSs,
                   dsx1CurrentUASs,
                   dsx1CurrentCSSs,
                   dsx1CurrentPCVs,
                   dsx1CurrentLESs,
                   dsx1CurrentBESs,
                   dsx1CurrentDMs,
                   dsx1CurrentLCVs,
                   dsx1IntervalIndex,
                   dsx1IntervalNumber,
                   dsx1IntervalESs,
                   dsx1IntervalSESs,
                   dsx1IntervalSEFSs,
                   dsx1IntervalUASs,
                   dsx1IntervalCSSs,
                   dsx1IntervalPCVs,
                   dsx1IntervalLESs,
                   dsx1IntervalBESs,
                   dsx1IntervalDMs,
                   dsx1IntervalLCVs,
                   dsx1IntervalValidData,
                   dsx1TotalIndex,
                   dsx1TotalESs,
                   dsx1TotalSESs,
                   dsx1TotalSEFSs,
                   dsx1TotalUASs,
                   dsx1TotalCSSs,
                   dsx1TotalPCVs,
                   dsx1TotalLESs,
                   dsx1TotalBESs,
                   dsx1TotalDMs,
                   dsx1TotalLCVs }
         STATUS  current
         DESCRIPTION
                 "A collection of objects providing statistics
                 information applicable to all DS1 interfaces."
         ::= { ds1Groups 2 }

     ds1FarEndGroup  OBJECT-GROUP
         OBJECTS { dsx1FarEndCurrentIndex,
                   dsx1FarEndTimeElapsed,

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                   dsx1FarEndValidIntervals,
                   dsx1FarEndCurrentESs,
                   dsx1FarEndCurrentSESs,
                   dsx1FarEndCurrentSEFSs,
                   dsx1FarEndCurrentUASs,
                   dsx1FarEndCurrentCSSs,
                   dsx1FarEndCurrentLESs,
                   dsx1FarEndCurrentPCVs,
                   dsx1FarEndCurrentBESs,
                   dsx1FarEndCurrentDMs,
                   dsx1FarEndInvalidIntervals,
                   dsx1FarEndIntervalIndex,
                   dsx1FarEndIntervalNumber,
                   dsx1FarEndIntervalESs,
                   dsx1FarEndIntervalSESs,
                   dsx1FarEndIntervalSEFSs,
                   dsx1FarEndIntervalUASs,
                   dsx1FarEndIntervalCSSs,
                   dsx1FarEndIntervalLESs,
                   dsx1FarEndIntervalPCVs,
                   dsx1FarEndIntervalBESs,
                   dsx1FarEndIntervalDMs,
                   dsx1FarEndIntervalValidData,
                   dsx1FarEndTotalIndex,
                   dsx1FarEndTotalESs,
                   dsx1FarEndTotalSESs,
                   dsx1FarEndTotalSEFSs,
                   dsx1FarEndTotalUASs,
                   dsx1FarEndTotalCSSs,
                   dsx1FarEndTotalLESs,
                   dsx1FarEndTotalPCVs,
                   dsx1FarEndTotalBESs,
                   dsx1FarEndTotalDMs }
         STATUS  current
         DESCRIPTION
                 "A collection of objects providing remote
                 configuration and statistics information."
         ::= { ds1Groups 3 }

     ds1DeprecatedGroup OBJECT-GROUP
         OBJECTS { dsx1IfIndex,
                   dsx1FracIndex,
                   dsx1FracNumber,
                   dsx1FracIfIndex }
         STATUS  deprecated
         DESCRIPTION
                 "A collection of obsolete objects that may be
                 implemented for backwards compatibility."

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         ::= { ds1Groups 4 }

     ds1NearEndOptionalConfigGroup OBJECT-GROUP
         OBJECTS { dsx1LineStatusLastChange,
                   dsx1LineStatusChangeTrapEnable }

         STATUS    current
         DESCRIPTION
                 "A collection of objects that may be implemented
                 on DS1 and DS2 interfaces."
         ::= { ds1Groups 5 }

     ds1DS2Group OBJECT-GROUP
         OBJECTS { dsx1LineIndex,
                   dsx1LineType,
                   dsx1LineCoding,
                   dsx1SendCode,
                   dsx1LineStatus,
                   dsx1SignalMode,
                   dsx1TransmitClockSource,
                   dsx1Channelization }
         STATUS   current
         DESCRIPTION
                 "A collection of objects providing information
                 about DS2 (6,312 kbps) and E2 (8,448 kbps)
                 systems."
         ::= { ds1Groups 6 }

     ds1TransStatsGroup OBJECT-GROUP
         OBJECTS { dsx1CurrentESs,
                   dsx1CurrentSESs,
                   dsx1CurrentUASs,
                   dsx1IntervalESs,
                   dsx1IntervalSESs,
                   dsx1IntervalUASs,
                   dsx1TotalESs,
                   dsx1TotalSESs,
                   dsx1TotalUASs }
         STATUS   current
         DESCRIPTION
                      "A collection of objects which are the
                 statistics which can be collected from a ds1
                 interface that is running transparent or unframed
                 lineType.  Statistics not in this list should
                 return noSuchInstance."
         ::= { ds1Groups 7 }

     ds1NearEndOptionalTrapGroup NOTIFICATION-GROUP

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         NOTIFICATIONS { dsx1LineStatusChange }
         STATUS    current
         DESCRIPTION
                 "A collection of notifications that may be
                 implemented on DS1 and DS2 interfaces."
         ::= { ds1Groups 8 }

     ds1ChanMappingGroup OBJECT-GROUP
         OBJECTS { dsx1ChanMappedIfIndex }
         STATUS    current
         DESCRIPTION
                 "A collection of objects that give an mapping of
                 DS3 Channel (ds1ChannelNumber) to ifIndex."
         ::= { ds1Groups 9 }

     END

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4.  Appendix A - Use of dsx1IfIndex and dsx1LineIndex

   This Appendix exists to document the previous use if dsx1IfIndex and
   dsx1LineIndex and to clarify the relationship of dsx1LineIndex as
   defined in rfc1406 with the dsx1LineIndex as defined in this
   document.

   The following shows the old and new definitions and the relationship:

   [New Definition]: "This object should be made equal to ifIndex.  The
   next paragraph describes its previous usage.  Making the object equal
   to ifIndex allows proper use of ifStackTable and ds0/ds0bundle mibs.

   [Old Definition]: "This object is the identifier of a DS1 Interface
   on a managed device.  If there is an ifEntry that is directly
   associated with this and only this DS1 interface, it should have the
   same value as ifIndex.  Otherwise, number the dsx1LineIndices with an
   unique identifier following the rules of choosing a number that is
   greater than ifNumber and numbering the inside interfaces (e.g.,
   equipment side) with even numbers and outside interfaces (e.g,
   network side) with odd numbers."

   When the "Old Definition" was created, it was described this way to
   allow a manager to treat the value _as if_ it were and ifIndex, i.e.
   the value would either be:  1) an ifIndex value or 2) a value that
   was guaranteed to be different from all valid ifIndex values.

   The new definition is a subset of that definition, i.e. the value is
   always an ifIndex value.

   The following is Section 3.1 from rfc1406:

   Different physical configurations for the support of SNMP with DS1
   equipment exist. To accommodate these scenarios, two different
   indices for DS1 interfaces are introduced in this MIB.  These indices
   are dsx1IfIndex and dsx1LineIndex.

   External interface scenario: the SNMP Agent represents all managed
   DS1 lines as external interfaces (for example, an Agent residing on
   the device supporting DS1 interfaces directly):

   For this scenario, all interfaces are assigned an integer value equal
   to ifIndex, and the following applies:

      ifIndex=dsx1IfIndex=dsx1LineIndex for all interfaces.

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   The dsx1IfIndex column of the DS1 Configuration table relates each
   DS1 interface to its corresponding interface (ifIndex) in the
   Internet-standard MIB (MIB-II STD 17, RFC1213).

   External&Internal interface scenario: the SNMP Agents resides on an
   host external from the device supporting DS1 interfaces (e.g., a
   router). The Agent represents both the host and the DS1 device.  The
   index dsx1LineIndex is used to not only represent the DS1 interfaces
   external from the host/DS1-device combination, but also the DS1
   interfaces connecting the host and the DS1 device.  The index
   dsx1IfIndex is always equal to ifIndex.

   Example:

   A shelf full of CSUs connected to a Router. An SNMP Agent residing on
   the router proxies for itself and the CSU. The router has also an
   Ethernet interface:


         +-----+
   |     |     |
   |     |     |               +---------------------+
   |E    |     |  1.544  MBPS  |              Line#A | DS1 Link
   |t    |  R  |---------------+ - - - - -  - - -  - +------>
   |h    |     |               |                     |
   |e    |  O  |  1.544  MBPS  |              Line#B | DS1 Link
   |r    |     |---------------+ - - - - - - - - - - +------>
   |n    |  U  |               |  CSU Shelf          |
   |e    |     |  1.544  MBPS  |              Line#C | DS1 Link
   |t    |  T  |---------------+ - - - -- -- - - - - +------>
   |     |     |               |                     |
   |-----|  E  |  1.544  MBPS  |              Line#D | DS1 Link
   |     |     |---------------+ -  - - - -- - - - - +------>
   |     |  R  |               |_____________________|
   |     |     |
   |     +-----+

   The assignment of the index values could for example be:

           ifIndex (= dsx1IfIndex)                     dsx1LineIndex
                   1                   NA                  NA (Ethernet)
                   2      Line#A   Router Side             6
                   2      Line#A   Network Side            7
                   3      Line#B   Router Side             8
                   3      Line#B   Network Side            9
                   4      Line#C   Router Side            10

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                   4      Line#C   Network Side           11
                   5      Line#D   Router Side            12
                   5      Line#D   Network Side           13

   For this example, ifNumber is equal to 5.  Note the following
   description of dsx1LineIndex:  the dsx1LineIndex identifies a DS1
   Interface on a managed device.  If there is an ifEntry that is
   directly associated with this and only this DS1 interface, it should
   have the same value as ifIndex.  Otherwise, number the
   dsx1LineIndices with an unique identifier following the rules of
   choosing a number greater than ifNumber and numbering inside
   interfaces (e.g., equipment side) with even numbers and outside
   interfaces (e.g., network side) with odd numbers.

   If the CSU shelf is managed by itself by a local SNMP Agent, the
   situation would be:

           ifIndex (= dsx1IfIndex)                      dsx1LineIndex
                   1      Line#A     Network Side            1
                   2      Line#A     RouterSide              2
                   3      Line#B     Network Side            3
                   4      Line#B     RouterSide              4
                   5      Line#C     Network Side            5
                   6      Line#C     Router Side             6
                   7      Line#D     Network Side            7
                   8      Line#D     Router Side             8

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5.  Appendix B - The delay approach to Unavialable Seconds.

   This procedure is illustrated below for a DS1 ESF interface.  Similar
   rules would apply for other DS1, DS2, and E1 interface variants.  The
   procedure guarantees that the statistical counters are correctly
   updated at all times, although they lag real time by 10 seconds.  At
   the end of each 15 minutes interval the current interval counts are
   transferred to the  most recent interval entry and each interval is
   shifted up by one position, with the oldest being discarded if
   necessary in order to make room.  The current interval counts then
   start over from zero.  Note, however, that the signal state
   calculation does not start afresh at each interval boundary;  rather,
   signal state information is retained across interval boundaries.

+---------------------------------------------------------------------+
|               READ COUNTERS & STATUS INFO FROM HARDWARE             |
|                                                                     |
| BPV EXZ LOS FE CRC CS AIS SEF OOF LOF       RAI G1-G6 SE FE LV SL   |
+---------------------------------------------------------------------+
   |   |   |   |  |   |  |   |   |   |         |    |    |  |  |  |
   |   |   |   |  |   |  |   |   |   |         |    |    |  |  |  |
   V   V   V   V  V   V  V   V   V   V         V    V    V  V  V  V
+---------------------------------------------------------------------+
|    ACCUM ONE-SEC STATS, CHK ERR THRESHOLDS, & UPDT SIGNAL STATE     |
|                                                                     |
|  |<---------- NEAR END ----------->|    |<-------- FAR END ------>| |
|                                                                     |
|  LCV LES PCV ES CSS BES SES SEFS A/U    PCV ES CSS BES SES SEFS A/U |
+---------------------------------------------------------------------+
    |   |   |  |   |   |   |   |    |      |  |   |   |   |   |    |
    |   |   |  |   |   |   |   |    |      |  |   |   |   |   |    |
    V   V   V  V   V   V   V   V    |      V  V   V   V   V   V    |
 +------------------------------+   |    +----------------------+  |
 |         ONE-SEC DELAY        |   |    |    ONE-SEC DELAY     |  |
 |           (1 OF 10)          |   |    |      (1 OF 10)       |  |
 +------------------------------+   |    +----------------------+  |
   |   |   |  |   |   |   |   |     |      |  |   |   |   |   |    |
   /   /   /  /   /   /   /   /     /      /  /   /   /   /   /    /
   |   |   |  |   |   |   |   |     |      |  |   |   |   |   |    |
   V   V   V  V   V   V   V   V     |      V  V   V   V   V   V    |
 +------------------------------+   |    +----------------------+  |
 |         ONE-SEC DELAY        |   |    |    ONE-SEC DELAY     |  |
 |           (10 OF 10)         |   |    |      (10 OF 10)      |  |
 +------------------------------+   |    +----------------------+  |
   |   |   |  |   |   |   |   |     |      |  |   |   |   |   |    |
   V   V   V  V   V   V   V   V     V      V  V   V   V   V   V    V

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+---------------------------------------------------------------------+
|                    UPDATE STATISTICS COUNTERS                       |
|                                                                     |
|<-------------- NEAR END ----------->| |<--------- FAR END --------->|
|                                                                     |
|LCV LES PCV ES CSS BES SES SEFS UAS DM PCV ES CSS BES SES SEFS UAS DM|
+---------------------------------------------------------------------+

   Note that if such a procedure is adopted there is no current interval
   data for the first ten seconds after a system comes up.
   noSuchInstance must be returned if a management station attempts to
   access the current interval counters during this time.

   It is an implementation-specific matter whether an agent assumes that
   the initial state of the interface is available or unavailable.

6.  Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   intellectual property or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; neither does it represent that it
   has made any effort to identify any such rights.  Information on the
   IETF's procedures with respect to rights in standards-track and
   standards-related documentation can be found in BCP-11.  Copies of
   claims of rights made available for publication and any assurances of
   licenses to be made available, or the result of an attempt made to
   obtain a general license or permission for the use of such
   proprietary rights by implementors or users of this specification can
   be obtained from the IETF Secretariat.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights which may cover technology that may be required to practice
   this standard.  Please address the information to the IETF Executive
   Director.

7.  Acknowledgments

   This document was produced by the Trunk MIB Working Group.

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8.  References

   [1]  Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture for
        Describing SNMP Management Frameworks", RFC 2271, January 1998.

   [2]  Rose, M. and K. McCloghrie, "Structure and Identification of
        Management Information for TCP/IP-based Internets", STD 16, RFC
        1155, May 1990.

   [3]  Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD 16,
        RFC 1212, March 1991.

   [4]  Rose, M., "A Convention for Defining Traps for use with the
        SNMP", RFC 1215, March 1991.

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

   [6]  Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Textual
        Conventions for Version 2 of the Simple Network Management
        Protocol (SNMPv2)", RFC 1903, January 1996.

   [7]  Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
        "Conformance Statements for Version 2 of the Simple Network
        Management Protocol (SNMPv2)", RFC 1904, January 1996.

   [8]  Case, J., Fedor, M., Schoffstall, M. and J. Davin, "Simple
        Network Management Protocol", STD 15, RFC 1157, May 1990.

   [9]  Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
        "Introduction to Community-based SNMPv2", RFC 1901, January
        1996.

   [10] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Transport
        Mappings for Version 2 of the Simple Network Management Protocol
        (SNMPv2)", RFC 1906, January 1996.

   [11] Case, J., Harrington D., Presuhn R. and B. Wijnen, "Message
        Processing and Dispatching for the Simple Network Management
        Protocol (SNMP)", RFC 2272, January 1998.

   [12] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM)
        for version 3 of the Simple Network Management Protocol
        (SNMPv3)", RFC 2274, January 1998.

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

   [14] Levi, D., Meyer, P. and B. Stewart, "SNMPv3 Applications", RFC
        2273, January 1998.

   [15] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access
        Control Model (VACM) for the Simple Network Management Protocol
        (SNMP)", RFC 2275, January 1998.

   [16] McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB
        using SMIv2", RFC 2233, November 1997.

   [17] AT&T Information Systems, AT&T ESF DS1 Channel Service Unit
        User's Manual, 999-100-305, February 1988.

   [18] AT&T Technical Reference, Requirements for Interfacing Digital
        Terminal Equipment to Services Employing the Extended Superframe
        Format, Publication 54016, May 1988.

   [19] American National Standard for Telecommunications -- Carrier-to-
        Customer Installation - DS1 Metallic Interface, T1.403, February
        1989.

   [20] CCITT Specifications Volume III, Recommendation G.703,
        Physical/Electrical Characteristics of Hierarchical Digital
        Interfaces, April 1991.

   [21] ITU-T G.704: Synchronous frame structures used at 1544, 6312,
        2048, 8488 and 44 736 kbit/s Hierarchical Levels, July 1995.

   [22] American National Standard for Telecommunications -- Digital
        Hierarchy -- Layer 1 In-Service Digital Transmission Performace
        Monitoring, T1.231, Sept 1993.

   [23] CCITT Specifications Volume IV, Recommendation O.162, Equipment
        To Perform In Service Monitoring On 2048 kbit/s Signals, July
        1988.

   [24] CCITT Specifications Volume III, Recommendation G.821, Error
        Performance Of An International Digital Connection Forming Part
        Of An Integrated Services Digital Network, July 1988.

   [25] AT&T Technical Reference, Technical Reference 62411, ACCUNET
        T1.5 Service Description And Interface Specification, December
        1990.

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   [26] CCITT Specifications Volume III, Recommendation G.706, Frame
        Alignment and Cyclic Redundancy Check (CRC) Procedures Relating
        to Basic Frame Structures Defined in Recommendation G.704, July
        1988.

   [27] CCITT Specifications Volume III, Recommendation G.732,
        Characteristics Of Primary PCM Multiplex Equipment Operating at
        2048 kbit/s, July 1988.

   [28] Fowler, D., "Definitions of Managed Objects for the DS3/E3
        Interface Types", RFC 2496, Janaury 1999.

   [29] Brown, T., and Tesink, K., "Definitions of Managed Objects for
        the SONET/SDH Interface Type", Work in Progress.

   [30] Fowler, D., "Definitions of Managed Objects for the Ds0 and
        DS0Bundle Interface Types", RFC 2494, January 1999.

   [31] ITU-T G.775: Loss of signal (LOS) and alarm indication signal
        (AIS) defect detection and clearance criteria, May 1995.

   [32] ITU-T G.826: Error performance parameters and objectives for
        international, constant bit rate digital paths at or above the
        primary rate, November 1993.

   [33] American National Standard for Telecommunications -- Digital
        Hierarchy - Electrical Interfaces, T1.102, December 1993.

   [34] American National Standard for Telecommunications -- Digital
        Hierarchy - Format Specifications, T1.107, August 1988.

   [35] Tesink, K., "Textual Conventions for MIB Modules Using
        Performance History Based on 15 Minute Intervals", RFC XXXX,
        January 1999.

9.  Security Considerations

   SNMPv1 by itself is such an insecure environment.  Even if the
   network itself is secure (for example by using IPSec), even then,
   there is no control as to who on the secure network is allowed to
   access and GET (read) the objects in this MIB.

   It is recommended that the implementors consider the security
   features as provided by the SNMPv3 framework.  Specifically, the use
   of the User-based Security Model RFC 2274 [12] and the View-based
   Access Control Model RFC 2275 [15] is recommended.

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   It is then a customer/user responsibility to ensure that the SNMP
   entity giving access to an instance of this MIB, is properly
   configured to give access to those objects only to those principals
   (users) that have legitimate rights to access them.

   Setting any of the following objects to an inappropriate value can
   cause loss of traffic.  The definition of inappropriate varies for
   each object.  In the case of dsx1LineType, for example, both ends of
   a ds1/e1 must have the same value in order for traffic to flow.  In
   the case of dsx1SendCode and dsx1LoopbackConfig, for another example,
   traffic may stop transmitting when particular loopbacks are applied.

      dsx1LineType
      dsx1LineCoding
      dsx1SendCode
      dsx1LoopbackConfig
      dsx1SignalMode
      dsx1TransmitClockSource
      dsx1Fdl
      dsx1LineLength
      dsx1Channelization

   Setting the following object is mischevious, but not harmful to
   traffic.

      dsx1CircuitIdentifier

   Setting the following object can cause an increase in the number of
   traps received by the network management station.

      dsx1LineStatusChangeTrabEnable

10.  Author's Address

   David Fowler
   Newbridge Networks
   600 March Road
   Kanata, Ontario, Canada K2K 2E6

   Phone: (613) 599-3600, ext 6559
   EMail: davef@newbridge.com

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11.  Full Copyright Statement

   Copyright (C) The Internet Society (1999).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.