RFC 1406 (rfc1406) - Page 3 of 50

Definitions of Managed Objects for the DS1 and E1 Interface Types

RFC 1406                       DS1/E1 MIB                   January 1993


   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 [1] 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 [7],
   subject to the additional requirements imposed by the SNMP.

2.1.  Format of Definitions

   Section 4 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 STD 16, RFC 1212 [2].

2.2.  Changes from RFC 1232

   The changes from RFC 1232 are the following:

     (1)  This MIB module contains three groups: DS1 Near End Group
          which is mandatory, DS1 Far End Group which is optional,
          and the Fractional Table, which is optional.

     (2)  The Far End Group is a new group and contains statistics
          that are collected from the far end DS1 interface.  The
          Far End Group may only be implemented by DS1 systems that
          use the facilities data link to exchange this information
          - both T1.403 and PUB 54016 define ways to exchange this
          information over data links; vendors may use other
          proprietary means to do this on various link types.

     (3)  ds1CSUIndex has been renamed dsx1LineIndex.  This object
          is the identifier of a DS1 Interface on a device.  On a
          CSU, a single DS1 data stream will cross two DS1
          interfaces, which have separate dsx1LineIndex values.

     (4)  ds1Index has been renamed dsx1IfIndex.  This value for
          this object is equal to the value of ifIndex from the
          Interfaces table of MIB II (STD 17, RFC 1213).

     (5)  an object has been added (dsx1TransmitClockSource) to
          indicate the source of transmit clock.



Trunk MIB Working Group