SNMP MIB Objects
E-33160-A2-GB21-50 January 1997
System Group – “sysServices” Object (system 7)
This object provides a value which indicates the set of
services that are potentially offered by the DSU/CSU.
Only the following values are supported.
•physical(1) – Layer 1 functionality for all
interfaces.
•datalink/subnetwork(2) – Layer 2 functionality
(SLIP, PPP) for the COM, AUX, and MODEM
ports.
•internet(4) – Layer 3 functionality (IP) for all
management links.
•end-to-end(8) – Layer 4 functionality (UDP) for all
management links.
Therefore, set this object to 15 (the sum
of 1 + 2 + 4 + 8).

Interface Group, MIB II

The Interfaces Group consists of an object indicating
the number of interfaces supported by the unit and an
interface table containing an entry for each interface. The
DSU/CSU provides an entry in the interface table for the
network interface, the DTE Drop/Insert (DSX-1)
interface, each of the synchronous data ports (1, 2, or 4
depending on the model), the COM port, the AUX port,
and the MODEM port, if they apply. The following
sections provide clarification for objects contained in the
Interface Group where it is not clear how the object
definition in MIB II is related to the DSU/CSU.
Interface Group – “ifNumber” Object (interfaces 1)
This variable contains the maximum number of MIB II
supported interfaces possible across the 31xx Series
product line (9). This is different from the MIB
description, which is defined as the number of interfaces
on the particular device. This change allows the use of the
same ifIndexes across all 31xx Series models.
Interface Group – “ifIndex” Object (ifEntry 1)
This object provides the index into the ifTable and
typically into tables in other MIBs also. The values of the
ifIndex object do not vary between models even though
not all indexes are supported for a particular model. When
an unsupported index is accessed, “noSuchName” is
returned.
The following are the values of the ifIndexes for all
DSU/CSU models:
•1–Net T1
•2–DTE T1
•3–COM port
•4–Modem port
•5–Auxiliary RS-232 port
•6–DCE port 1
•7–DCE port 2
•8–DCE port 3
•9–DCE port 4
The supported ifIndexes for the 3160 DSU/CSU are:
•Net T1
•DTE T1
•COM port
•Modem port
•Auxiliary RS-232 port
•DCE port 1
•DCE port 2
The supported ifIndexes for the 3164 DSU/CSU are:
•Net T1
•DTE T1
•COM port
•Modem port
•Auxiliary RS-232 port
•DCE port 1
•DCE port 2
•DCE port 3
•DCE port 4
The supported ifIndexes for the 3165 DSU/CSU are:
•Net T1
•COM port
•Modem port
•DCE port 1