Cisco CISCO2650 - 2650 Router Hardware Installation Manual page 161

Chapter 9 Connecting Digital Modem Network Modules
Each modem in a digital modem module is also assigned a port number in the range 0 to 29. Modems in
the left MICA module (as viewed from the rear of the router), bank 0, are assigned port numbers 0 to 5.
Additional MICA modules, if present, are assigned port numbers as follows:
port-number = (6 x bank-number) + modem-number
For example, the third modem (modem 2) in the second MICA module from the left (bank 1) is assigned
port number (6 x 1) + 2 = 8.
Some Cisco IOS commands identify ports by interface number (or line number or TTY number, which
is the same as the interface number) rather than slot and port number. The interface number of a modem
port is related to its slot and port number in the following way:
interface-number = (32 x slot-number) + port-number + 1
This can also be expressed as:
interface-number = (32 x slot-number) + ((6 x bank-number) + modem-number) + 1
For example, if the module containing the modem in the last example is placed in slot 2, the modem is
assigned interface number (32 x 2) + ((6 x 1) + 2) + 1 = (32 x 2) + 8 + 1 = 73. This is also the line and
TTY number for the port. The modem in this position is always assigned interface 73, whether or not
there are other MICA modules in the digital modem network module or other digital modem network
modules in the router chassis. If you move the MICA module to a different position in the digital modem
network module, however, or move the digital modem network module to a different slot in the router
chassis, the interface number changes.
Table 9-1
assigned to the console.
Table 9-1
Slot Number
0
1
2
3
4
5
6
Adding 6-Port MICA Modules to a Digital Modem
Network Module
You can add modems to a digital modem network module, in groups of six, by installing additional 6-port
MICA modules, up to a maximum of five MICA modules (30 modems).
MICA modules are manufactured with a polarization notch to ensure proper orientation, and alignment
holes that fit over guide posts to ensure proper positioning. (See
OL-2485-20
shows the range of interface numbers available in each router slot. Interface 0 is automatically
Digital Modem Network Module Interface Numbering
Interface Numbers
1–30
33–62
65–94
97–126
129–158
161–190
193–222
Adding 6-Port MICA Modules to a Digital Modem Network Module
Figure 9-2.)
Cisco Network Modules Hardware Installation Guide
9-3