RFC 1406 (rfc1406) - Page 3 of 50
Definitions of Managed Objects for the DS1 and E1 Interface Types
Alternative Format: Original Text Document
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