NM-8B-U Cisco 8-Port ISDN BRI Network Module with NT1, U Interface

The Cisco NM-8B-U brings eight ISDN BRI lines into a modular router through the U interface, with an NT1 integrated in the module, which removes the need for a separate NT1 device between the ports and the ISDN WAN. The module is also numbered CPANM-8B-U and is known as the 8-port BRI U network module. Its 4-port partner is the NM-4B-U 4-port ISDN BRI network module with NT1.

Eight red RJ-45 jacks are the BRI ports, and a straight-through RJ-45-to-RJ-45 cable links each one to an RJ-45 ISDN jack. The module enable (EN) LED comes on after its self-test. For every port there are three LEDs: B1 and B2 follow activity on the two B channels, and NT1 follows the synchronization status of the NT1.

Cisco 3600 series routers with a digital modem network module (NM-6DM, NM-12DM, NM-18DM, NM-24DM or NM-30DM) need an NM-8B-U at revision 800-01239-06 or higher, and a board number below -06 means an upgrade. The module works in Cisco 2600 series, 2811, 2821, 2851, 3600 series, 3700 series and 3800 series routers, and it shares a chassis with a PRI network module only on Cisco IOS Release 11.3(3)T or later. Cisco interface cards has the wider selection of network modules to browse.