rfc2495.txt

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        DS1 case, "Distant Alarm" in the E1 case, and "Remote Alarm" in
        the DS2 case.

        For D4 links, the Far End Alarm failure is declared when bit 6
        of all channels has been zero for at least 335 ms and is cleared
        when bit 6 of at least one channel is non-zero for a period T,
        where T is usually less than one second and always less than 5
        seconds.  The Far End Alarm failure is not declared for D4 links
        when a Loss of Signal is detected.

        For ESF links, the Far End Alarm failure is declared if the
        Yellow Alarm signal pattern occurs in at least seven out of ten
        contiguous 16-bit pattern intervals and is cleared if the Yellow
        Alarm signal pattern does not occur in ten contiguous 16-bit
        signal pattern intervals.

        For E1 links, the Far End Alarm failure is declared when bit 3
        of time-slot zero is received set to one on two consecutive
        occasions.  The Far End Alarm failure is cleared when bit 3 of
        time-slot zero is received set to zero.

        For DS2 links, if a loss of frame alignment (LOF or LOS) and/or
        DS2 AIS condition, is detected, the RAI signal shall be
        generated and transmitted to the remote side.

        The Remote Alarm Indication(RAI) signal is defined on m-bits as
        a repetition of the 16bit sequence consisting of eight binary
        '1s' and eight binary '0s' in m-bits(1111111100000000).  When
        the RAI signal is not sent (in normal operation),the HDLC flag
        pattern (01111110) in the m-bit is sent.

        The RAI failure is detected when 16 or more consecutive RAI-
        patterns (1111111100000000) are received.  The RAI failure is
        cleared when 4 or more consecutive incorrect-RAI-patterns are
        received.

    Alarm Indication Signal (AIS) Failure
        The Alarm Indication Signal failure is declared when an AIS
        defect is detected at the input and the  AIS defect still exists
        after the Loss Of Frame failure (which is caused by the unframed
        nature of the 'all-ones' signal) is declared. The AIS failure is
        cleared when the Loss Of Frame failure is cleared.  (See T1.231
        Section 6.2.1.2.1)






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RFC 2495                   DS1/E1/DS2/E2 MIB                January 1999


        An AIS defect at a 6312 kbit/s (G.704) interface is detected
        when the incoming signal has two {2} or less ZEROs in a sequence
        of 3156 bits (0.5ms).

        The AIS signal defect is cleared when the incoming signal has
        three {3} or more ZEROs in a sequence of 3156 bits (0.5ms).

    Loss Of Frame Failure
        For DS1 links, the Loss Of Frame failure is declared when an OOF
        or LOS  defect has persisted for T seconds, where 2 <= T <= 10.
        The Loss Of Frame failure is cleared when there have been no OOF
        or LOS defects during a period T where 0 <= T <= 20.  Many
        systems will perform "hit integration" within the period T
        before declaring or clearing the failure e.g., see TR 62411
        [25].

        For E1 links, the Loss Of Frame Failure is declared when an OOF
        defect is detected.

    Loss Of Signal Failure
        For DS1, the Loss Of Signal failure is declared upon observing
        175 +/- 75 contiguous pulse positions with no pulses of either
        positive or negative polarity.  The LOS failure is cleared upon
        observing an average pulse density of at least 12.5% over a
        period of 175 +/- 75 contiguous pulse positions starting with
        the receipt of a pulse.

        For E1 links, the Loss Of Signal failure is declared when
        greater than 10 consecutive zeroes are detected (see O.162
        Section 3.4`<.4).

        A LOS defect at 6312kbit/s interfaces is detected when the
        incoming signal has "no transitions", i.e. when the signal level
        is less than or equal to a signal level of 35dB below nominal,
        for N consecutive pulse intervals, where 10 <=N<=255.

        The LOS defect is cleared when the incoming signal has
        "transitions", i.e. when the signal level is greater than or
        equal to a signal level of 9dB below nominal, for N consecutive
        pulse intervals, where 10<=N<=255.

        A signal with "transitions" corresponds to a G.703 compliant
        signal.








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RFC 2495                   DS1/E1/DS2/E2 MIB                January 1999


    Loopback Pseudo-Failure
        The Loopback Pseudo-Failure is declared when the near end
        equipment has placed a loopback (of any kind) on the DS1.  This
        allows a management entity to determine from one object whether
        the DS1 can be considered to be in service or not (from the
        point of view of the near end equipment).

    TS16 Alarm Indication Signal Failure
        For E1 links, the TS16 Alarm Indication Signal failure is
        declared when time-slot 16 is received as all ones for all
        frames of two consecutive multiframes (see G.732 Section 4.2.6).
        This condition is never declared for DS1.

    Loss Of MultiFrame Failure
        The Loss Of MultiFrame failure is declared when two consecutive
        multiframe alignment signals (bits 4 through 7 of TS16 of frame
        0) have been received with an error.  The Loss Of Multiframe
        failure is cleared when the first correct multiframe alignment
        signal is received.  The Loss Of Multiframe failure can only be
        declared for E1 links operating with G.732 [27] framing
        (sometimes called "Channel Associated Signalling" mode).

    Far End Loss Of Multiframe Failure
        The Far End Loss Of Multiframe failure is declared when bit 2 of
        TS16 of frame 0 is received set to one on two consecutive
        occasions.  The Far End Loss Of Multiframe failure is cleared
        when bit 2 of TS16 of frame 0 is received set to zero.  The Far
        End Loss Of Multiframe failure can only be declared for E1 links
        operating in "Channel Associated Signalling" mode. (See G.732)

    DS2 Payload AIS Failure
        The DS2 Payload AIS is detected when the incoming signal of the
        6,312 kbps frame payload [TS1-TS96] has 2 or less 0's in a
        sequence of 3072 bits (0.5ms).  The DS2 Payload AIS is cleared
        when the incoming signal of the 6,312 kbps frame payload [TS1-
        TS96] has 3 or more 0's in a sequence of 3072 bits (0.5 ms).

    DS2 Performance Threshold
        DS2 Performance Threshold Failure monitors equipment performance
        and is based on the CRC (Cyclic Redundancy Check) Procedure
        defined in G.704.

        The DS2 Performance Threshold Failure is detected when the bit
        error ratio exceeds 10^-4 (Performance Threshold), and the DS2
        Performance Threshold Failure shall be cleared when the bit
        error ratio decreased to less than 10^-6."





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RFC 2495                   DS1/E1/DS2/E2 MIB                January 1999


2.4.5.  Other Terms

    Circuit Identifier
        This is a character string specified by the circuit vendor, and
        is useful when communicating with the vendor during the
        troubleshooting process.

    Proxy
        In this document, the word proxy is meant to indicate an
        application which receives SNMP messages and replies to them on
        behalf of the devices which implement the actual DS3/E3
        interfaces.  The proxy may have already collected the
        information about the DS3/E3 interfaces into its local database
        and may not necessarily forward the requests to the actual
        DS3/E3 interface.  It is expected in such an application that
        there are periods of time where the proxy is not communicating
        with the DS3/E3 interfaces.  In these instances the proxy will
        not necessarily have up-to-date configuration information and
        will most likely have missed the collection of some statistics
        data.  Missed statistics data collection will result in invalid
        data in the interval table.

3.  Object Definitions

     DS1-MIB DEFINITIONS ::= BEGIN

     IMPORTS
          MODULE-IDENTITY, OBJECT-TYPE,
          NOTIFICATION-TYPE, transmission         FROM SNMPv2-SMI
          DisplayString, TimeStamp, TruthValue    FROM SNMPv2-TC
          MODULE-COMPLIANCE, OBJECT-GROUP,
          NOTIFICATION-GROUP                      FROM SNMPv2-CONF
          InterfaceIndex, ifIndex                 FROM IF-MIB
          PerfCurrentCount, PerfIntervalCount,
          PerfTotalCount                          FROM PerfHist-TC-MIB;


     ds1 MODULE-IDENTITY
         LAST-UPDATED "9808011830Z"
         ORGANIZATION "IETF Trunk MIB Working Group"
         CONTACT-INFO
           "        David Fowler

            Postal: Newbridge Networks Corporation
                    600 March Road
                    Kanata, Ontario, Canada K2K 2E6

                    Tel: [phone]



Fowler, Ed.                 Standards Track                    [Page 21]

RFC 2495                   DS1/E1/DS2/E2 MIB                January 1999


                    Fax: [phone]

            E-mail: [e-mail]"
         DESCRIPTION
              "The MIB module to describe DS1, E1, DS2, and
               E2 interfaces objects."

         ::= { transmission 18 }

     -- note that this subsumes cept (19) and g703at2mb (67)
     -- there is no separate CEPT or G703AT2MB MIB

     -- The DS1 Near End Group

     -- The DS1 Near End Group consists of five tables:
     --    DS1 Configuration
     --    DS1 Current
     --    DS1 Interval
     --    DS1 Total
     --    DS1 Channel Table

     -- The DS1 Configuration Table

     dsx1ConfigTable OBJECT-TYPE
          SYNTAX  SEQUENCE OF Dsx1ConfigEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "The DS1 Configuration table."
          ::= { ds1 6 }

     dsx1ConfigEntry OBJECT-TYPE
          SYNTAX  Dsx1ConfigEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "An entry in the DS1 Configuration table."
          INDEX   { dsx1LineIndex }
          ::= { dsx1ConfigTable 1 }

     Dsx1ConfigEntry ::=
          SEQUENCE {
              dsx1LineIndex                        InterfaceIndex,
              dsx1IfIndex                          InterfaceIndex,
              dsx1TimeElapsed                      INTEGER,
              dsx1ValidIntervals                   INTEGER,
              dsx1LineType                         INTEGER,
              dsx1LineCoding                       INTEGER,



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RFC 2495                   DS1/E1/DS2/E2 MIB                January 1999


              dsx1SendCode                         INTEGER,
              dsx1CircuitIdentifier                DisplayString,
              dsx1LoopbackConfig                   INTEGER,
              dsx1LineStatus                       INTEGER,
              dsx1SignalMode                       INTEGER,
              dsx1TransmitClockSource              INTEGER,
              dsx1Fdl                              INTEGER,
              dsx1InvalidIntervals                 INTEGER,
              dsx1LineLength                       INTEGER,
              dsx1LineStatusLastChange             TimeStamp,
              dsx1LineStatusChangeTrapEnable       INTEGER,
              dsx1LoopbackStatus                   INTEGER,
              dsx1Ds1ChannelNumber                 INTEGER,
              dsx1Channelization                   INTEGER
     }

     dsx1LineIndex OBJECT-TYPE
          SYNTAX  InterfaceIndex
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "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.

                 Previously, 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."
          ::= { dsx1ConfigEntry 1 }

     dsx1IfIndex OBJECT-TYPE
          SYNTAX  InterfaceIndex
          MAX-ACCESS  read-only