Cisco Fourth-Gen Network Interface Module 4-Port Voice/Fax

The Cisco NIM-4FXSP= is a fourth-generation network interface module that brings four analog voice and fax ports to a Cisco ISR 4000 Series router. By placing these ports directly on the router, it lets you connect traditional telephones, fax machines, or analog trunks without relying on external gateways.

The module installs in an ISR 4000 network interface slot, and its online insertion and removal feature allows you to add or replace the card while the router remains powered. This reduces maintenance windows and keeps voice services available. Higher port density than earlier models means a single router can handle more analog endpoints, helping branch sites consolidate equipment and save rack space.

Many administrators choose the NIM-4FXSP= when they need to keep analog lines for elevators, alarms, or legacy fax workflows while migrating the rest of the network to IP. It also fits small call centers that still use analog handsets. Because the module runs on familiar Cisco IOS software, you can apply the same dial peer, codec, and quality of service policies used on other Cisco voice interfaces.

Setup is straightforward: slide the card into the router, configure the ports in IOS, and connect standard RJ-11 cables to your analog devices. Once in place, the router can mix analog calls with SIP or H.323 traffic, giving you a single control point for all voice paths.

• Provides four analog voice and fax ports for Cisco ISR 4000 Series routers
• Supports online insertion and removal, minimizing downtime during upgrades
• Delivers higher port density than earlier Cisco voice interface modules
• Enables flexible configuration through Cisco IOS software
• Works with telephones, fax machines, and analog trunks in branch or small enterprise environments