F. SNMP MIB Objects3160-A2-GB24-10 March 2001 F-19DS1 Fractional Group, DS1/E1 MIBThe DS1 Fractional Group consists of the DS1 fractional table. This table(dsx1FracTable) is fully supported by the DSU/CSU and allows channel (timeslots) to be mapped between the T1 interfaces and data ports. If an invalid channelmap (e.g., two interfaces mapped to a single time slot, one interface mapped totwo T1s, etc.) is received, an error will be returned to the SNMP manager. TheDSU/CSU will validate all channel configurations before applying them.Operational Note: The fractional T1 group only allows specification of an entireinterface to a particular time slot on another interface (i.e., a time slot on oneinterface cannot be mapped to a time slot on another interface). This preventscomplete mapping of time slots on the DTE Drop/Insert (DSX-1) interface to timeslots on the network interface. For mapping time slots between the network andDTE T1 interfaces, the following convention is used: Time slots on the T1 interfacethat are mapped to another T1 interface (i.e., not a data port) are connected inascending order. For example, if the fractional table for the network interface mapstime slots 1, 3 and 5 to the DTE T1 interface and the DTE T1 interface maps timeslots 10, 11 and 15 to the network the following time slots will be connected: N1 toD10, 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 synchronousdata ports, the MODEM port, the COM port, and the AUX port. The RS-232-likeMIB 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 TableThe Asynchronous Port table is not supported by the DSU/CSU for thesynchronous data ports. The Input Signal and Output Signal tables are notsupported for the MODEM, AUX, and COM ports. The following sections provideclarification for objects contained in the RS-232-like MIB when it is not clear howthe 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. Thisnumber is 5 for the 3160, 7 for the 3164, 3 for the 3165 and 2 for the 3161.
