Analog Modem WAN Interface Cards
Understanding Interface Numbering on Analog Modem WICs
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Understanding Interface Numbering on Analog Modem WICs
Cisco IOS software identifies each modem uniquely by its slot number and port number.
Some Cisco IOS configuration commands identify asynchronous ports by an interface number (or a line
number, which is the same as the interface number). The interface number of a port on an 1-port or 2-port
analog WAN interface card is related to the slot number where the card is installed and the number of
the port in the card.
Slot numbering conventions for Cisco interface cards are explained in the
“Interface Card Slots
Available on Cisco Access Routers” section on page -8
.
Ports in the 1- and 2-port analog modem WAN interface cards are numbered in the same pattern as slot
numbers, beginning at 0 at the lower right and continuing from right to left.
The interface number of a port is determined in the following way:
interface-number
= (32 x
slot-number
) +
port-number
+ 1
For example, modem port 1 in slot 1 corresponds to interface number (32 x 1) + 1 + 1 = 34. This is also
the line number for the port. Port 1 in slot 1 is always assigned interface number 34, regardless of what
is in slot 0. If you move the card from slot 1 to a different slot, however, its interface numbers change.
Table 29
shows the range of interface numbers available for each type of analog modem card in each
router slot. (Interface 0 is automatically assigned to the console.)
Connecting an Analog Modem WIC to a Network
Use a straight-through RJ-11-to-RJ-11 cable (not included) to connect an analog modem WIC to a
network.
Step 1
Turn off and confirm that the router is turned off.
Warning
To comply with the Telcordia GR-1089 NEBS standard for electromagnetic compatibility and safety,
connect the WIC-1AM-V2 and WIC-2AM-V2 interface cards only to intra-building or unexposed wiring
or cable. The intrabuilding cable must be shielded and the shield must be grounded at both ends. The
intra-building port(s) of the equipment or subassembly must not be metallically connected to
interfaces that connect to the OSP or its wiring. These interfaces are designed for use as
Table 29
1- and 2-Port Analog Modem WIC Numbering
Slot Number
Interface (1-Port WICs)
Interface (2-Port WICs)
0
1
1–2
1
33
33–34
2
65
65–66
3
97
97–98
4
129
129–130
5
161
161–162
6
193
193–194
