NM-8B-S/T Cisco 8-Port ISDN BRI Network Module, S/T Interface

The NM-8B-S/T is the 8-port Cisco ISDN BRI network module with an S/T interface, also numbered CPANM-8B-S/T. All eight ports are RJ-45 jacks colored orange, and each one reaches an ISDN WAN through a separate NT1 device on a straight-through RJ-45-to-RJ-45 cable. The 4-port module in the same family is the NM-4B-S/T 4-port ISDN BRI network module.

A Cisco 3600 series router that also holds a digital modem network module (NM-6DM, NM-12DM, NM-18DM, NM-24DM or NM-30DM) needs a BRI board at revision 800-01237-03 or higher. Earlier revisions cannot send modem calls to the digital modem module, and a board number ending in -01 or -02 is due for an upgrade. The revision is printed on the board label, where the part number begins with 800-, and the IOS diagnostic output on the router reports it as well. A wrong revision brings a boot message that the BRI module in the slot is incompatible with the digital modems.

The EN LED comes on when the module has passed its self-tests and is ready for the router, and each port has B1 and B2 LEDs for call activity on the two B channels. Supported routers are the Cisco 2600 series, 2811, 2821, 2851, 3600 series, 3700 series and 3800 series. A BRI module and a PRI network module can sit in one chassis only on Cisco IOS Release 11.3(3)T or later. Cisco interface cards is the category to browse for further network modules.