|
|
This chapter describes how to connect 6-, 12-, 18-, 24-, and 30-port digital modem network modules (Cisco product numbers NM-6DM, NM-12DM, NM-18DM, NM-24DM, and NM-30DM) for Cisco modular routers. It contains the following sections:
These modules (see Figure 10-1) contain 6, 12, 18, 24, or 30 V.34+ digital modems for a direct digital connection to an Integrated Services Digital Network (ISDN) Primary Rate Interface (PRI) or Basic Rate Interface (BRI) channel, allowing you to mix digital and analog calls to provide remote access to a LAN.
 |
Note Digital modem network modules are supported in Cisco 3600 series routers only. |
Digital modem network modules do not provide network interfaces of their own, but instead handle analog calls passing through other router interfaces. In addition to the digital modem module, the router must contain a PRI or BRI interface to connect to the ISDN channel, and another interface, such as Ethernet, to provide connectivity to the LAN. The PRI or BRI module concurrently handles digital ISDN data connections and remote voice-channel (analog) modem connections, allowing a dynamic mix of digital and modem connections. The digital modem module acts as a pool of available modems that can be used for both incoming and outgoing calls.
Each digital modem module contains from one to five banks of 6-port modem ISDN channel aggregation (MICA) modules. You can add modems to a module, in groups of six, by installing additional MICA modules (Cisco product number MICA-6MOD), up to a maximum of 30 modems.
To use, digital modem network modules, Cisco 3620 and Cisco 3640 routers require Cisco IOS Release 11.2(9)XA or 11.2(10)P or later. The Cisco 3660 router requires Cisco IOS Release 12.0(7)XK or later.
In addition to the digital modem module, the router must contain a PRI or BRI network interface to connect to the ISDN channel, and another interface, such as Ethernet or Fast Ethernet, to provide connectivity to the LAN.
A PRI network module (Cisco product number NM-1CT1, NM-2CT1, NM-1CT1-CSU, NM-2CT1-CSU, NM-1CE1B, NM-2CE1B, NM-1CE1U, or NM-2CE1U) used with a digital modem module must be revision level -03 or higher. A BRI S/T network module (Cisco part number NM-4B-S/T or NM-8B-S/T) must be revision level -03 or higher, and a BRI U module (Cisco product number NM-4B-U or NM-8B-U) must be revision level -06 or higher. Earlier revisions of these network modules cannot send modem calls to the digital modem module.
If the PRI or BRI module is the wrong revision, you see a message similar to this one when the router boots:
The T1 or E1 network module in slot 0 is incompatible with the digital modems installed in the router.
To determine the revision level, you can examine the network module itself (outside the router), or use the Cisco IOS show diag command. The label on the module board should show a part number beginning with 800- and ending with the revision level. The output of the show diag command looks similar to the following:
Slot 3: Port adapter is analyzed Port adapter insertion time unknown Hardware revision 1.0 Board revision A0 Serial number 4152626 Part number 800-01228-01 Test history 0x0 RMA number 00-00-00 EEPROM format version 1 EEPROM contents (hex): 0x20: 01 26 01 00 00 3F 5D 32 50 04 CC 01 00 00 00 00 0x30: 50 00 00 00 96 11 04 17 FF FF FF FF FF FF FF FF
To order network module upgrades, see the "Cisco Connection Online" section.
Individual digital modem ports are not physically distinct, but Cisco IOS software identifies each modem uniquely through its slot number and port number. Cisco 3600 series slot numbering is explained in the "Cisco 3600 Series Interface Numbering" section.
Each digital modem module can hold up to five banks of MICA modules, numbered 0 to 4 from left to right (as viewed from the rear of the router). Each MICA module holds six modems, which are assigned modem numbers 0 to 5.
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 the port numbers shown in Table 10-1.
This relation can be expressed as:
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 are 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 10-1 shows the range of interface numbers available in each router slot. Interface 0 is automatically assigned to the console.
| Slot Number | Interface Numbers |
|---|---|
0 | 1-30 |
1 | 33-62 |
2 | 65-94 |
3 | 97-126 |
4 | 129-158 |
5 | 161-190 |
6 | 193-222 |
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 Figure 10-2.)
 |
Caution To avoid damaging electrostatic discharge (ESD)-sensitive components, observe all ESD precautions when handling MICA modules. To avoid damaging the network module or the MICA module, avoid excessive force when you remove or replace MICA modules. |
To remove, replace, or install a MICA module, you must first remove the digital modem module from the router chassis.
Follow this procedure to remove a digital modem network module:
The following warning applies to routers that use a DC power supply:
Step 2 Loosen the module's captive mounting screws, using a Phillips or flat-blade screwdriver.
Step 3 Hold the captive screws between two fingers, and pull the network module toward you until it slides free of the chassis. (See Figure 10-3.)
Step 4 Set the network module on an ESD-preventive mat.
To remove a MICA module from the digital modem network module, follow these steps:
|
Caution Handle MICA modules by the card edges only. MICA modules are ESD-sensitive components and can be damaged by mishandling. |
Step 2 Remove one MICA module at a time, beginning with the one farthest from you.
Step 3 To lift the MICA module out of its socket, pull the spring clips on both sides outward (see Figure 10-4) and tilt the MICA module away from you until it is free of the clips (see Figure 10-5).
Step 4 Hold the MICA module by the edges with your thumb and index finger and lift it out of the socket. (See Figure 10-6.) Place the removed MICA module in an antistatic bag to protect it from ESD damage.
Step 5 Repeat Step 2 through Step 4 for any remaining MICA modules that you want to remove.
Follow these steps to install new or replacement MICA modules:
|
Caution Handle MICA modules by the card edges only. MICA modules are ESD-sensitive components and can be damaged by mishandling. |
Step 2 Hold the MICA module with the connector edge at the bottom and the polarization notch at the right.
Step 3 Tilting the MICA module toward you at about a 45-degree angle, insert it into a socket, beginning with the empty socket closest to you. (See Figure 10-7.) Rock it downward, using the minimum amount of force required. (See Figure 10-8.) When the MICA module is properly seated, the socket guide posts fit through the alignment holes, and the spring clips click into place.
Step 4 Ensure that the MICA module is straight and that the alignment holes line up with the plastic guides on the socket. It is normal to feel some resistance, but do not use excessive force on the MICA module, and do not touch the surface components.
Step 5 Repeat Step 2 through Step 4 for any additional MICA modules.
When you finish installing MICA modules, replace the digital modem network module in the router chassis, following this procedure:
Step 2 Push the module into place until you feel its edge connector mate securely with the connector on the motherboard.
Step 3 Fasten the module's captive mounting screws into the holes in the chassis, using the Phillips or flat-blade screwdriver.
Step 4 If the router was previously running, reinstall the network interface cables and turn ON power to the router.
The following warning applies to routers that use a DC power supply:
 |
Warning After wiring the DC power supply, remove the tape from the circuit breaker switch handle and reinstate power by moving the handle of the circuit breaker to the ON position. |
All network modules have an enable (EN) LED. (See Figure 10-9.) This LED indicates that the module has passed its self-tests and is available to the router.
Digital modem modules have five additional LEDs, one for each MICA module bank. The LEDs blink during initialization. After the enable LED comes on, the MICA module LEDs indicate that the corresponding MICA module is functioning. If a MICA module fails its diagnostics, or if no MICA module is installed in a position, its LED remains off.
Posted: Fri Jun 2 16:56:40 PDT 2000
Copyright 1989 - 2000©Cisco Systems Inc.