SNMP MIB Objects

E-19

3160-A2-GB21-80 March 1999

DS1 Fractional Group, DS1/E1 MIB

The DS1 Fractional Group consists of the DS1 fractional table. This table
(dsx1FracTable) is fully supported by the DSU/CSU and allows channel (time
slots) to be mapped between the T1 interfaces and data ports. If an invalid
channel map (e.g., two interfaces mapped to a single time slot, one interface
mapped to two T1s, etc.) is received, an error will be returned to the SNMP
manager. The DSU/CSU will validate all channel configurations before applying
them.
Operational Note: The fractional T1 group only allows specification of an entire
interface to a particular time slot on another interface (i.e., a time slot on one
interface cannot be mapped to a time slot on another interface). This prevents
complete mapping of time slots on the DTE Drop/Insert (DSX-1) interface to time
slots on the network interface. For mapping time slots between the network and
DTE T1 interfaces, the following convention is used: Time slots on the T1
interface that are mapped to another T1 interface (i.e., not a data port) are
connected in ascending order. For example, if the fractional table for the network
interface maps time slots 1, 3 and 5 to the DTE T1 interface and the DTE T1
interface maps time slots 10, 11 and 15 to the network the following time slots will
be connected: N1 to D10, N3 to D11 and N5 to D15.
RS-232-like MIB (RFC 1317)
The “rs232” object defined by RFC 1317 is supported for all of the synchronous
data ports, the MODEM port, the COM port, and the AUX port. The RS-232-like
MIB consists of one object and five tables, as follows:
Number of RS-232-like ports
The General Port Table
The Asynchronous Port Table
The Synchronous Port Table
The Input Signal Table
The Output Signal Table
The Asynchronous Port table is not supported by the DSU/CSU for the
synchronous data ports. The Input Signal and Output Signal tables are not
supported for the MODEM, AUX, and COM ports. The following sections provide
clarification for objects contained in the RS-232-like MIB when it is not clear how
the object definition in MIB is related to the DSU/CSU.
Number of Ports – “rs232Number” Object (rs232 1)
This object contains the number of ports in the RS-232-like general port table.
This number is 5 for the 3160, 7 for the 3164, 3 for the 3165 and 2 for the 3161.