Cisco NM-4B S/T enterprise networking (router/Catalyst switch/UCS families) Router Line Card

The Cisco NM-4B S/T is a four port ISDN basic rate network module presenting S/T interfaces. S/T means the module connects to an NT1 network termination rather than directly to the line, which is the arrangement used across most of Europe where the NT1 is provided by the carrier. Four BRI ports on one module suited dial backup, small branch aggregation and legacy videoconferencing, all applications that kept ISDN alive well past its expected retirement.

The network module and WAN interface card system was Cisco’s answer to branch office variety. A 2600, 3600, 3700 or later chassis provides slots, and the modules decide what the router actually terminates, whether that is Ethernet, ISDN, serial, DSL or an on-board service. Because the same card fits several chassis generations, these parts stayed useful long after the routers they were bought for, and they remain a routine maintenance item.

Let us know which system this is destined for and we will verify the item in stock against it. Tech-Star (UK-based, shipped worldwide) holds equipment for maintenance and expansion projects. Please contact our sales team for availability, condition and pricing.