Description:

The Cisco NIM-4FXO 4-Port FXO Network Interface Module is used in Cisco Integrated Services Router 4000 Series platforms to provide analog voice connectivity to public switched telephone network (PSTN) lines. Commonly installed in enterprise voice gateways, branch office communication systems, and unified communications deployments where integration between IP telephony systems and traditional analog telephone lines is required. Maintenance teams, network administrators, and system integrators use this module for VoIP gateway deployment, telephony infrastructure expansion, analog trunk connectivity, and replacement of existing voice interface modules in Cisco ISR 4000 Series routers.

Applications:

The Cisco NIM-4FXO module is deployed in VoIP gateway environments to connect analog PSTN lines to IP-based communication systems, allowing organizations to route external phone calls through Cisco unified communications platforms. It is commonly used in corporate branch offices, call centers, government facilities, and enterprise telephony systems where businesses require reliable integration between traditional telephone networks and modern IP voice infrastructures.

Technical Specifications:

• Manufacturer Part Number (MPN): NIM-4FXO
• Product Type: Network Interface Module (Voice)
• Ports: 4 × FXO analog voice ports
• Interface Type: FXO (Foreign Exchange Office) for PSTN connectivity
• Router Compatibility: Cisco ISR 4000 Series routers
• Connector Type: RJ11 analog voice connectors
• Function: Connects PSTN lines to VoIP gateway systems
• Signaling Support: Analog telephony signaling
• Installation Type: NIM slot module for compatible Cisco routers
• Management: Configured through Cisco IOS XE voice gateway features
• Application Environment: Enterprise VoIP gateway and unified communications systems

Common Replacements:

• Cisco NIM-2FXO Voice Interface Module
• Cisco NIM-4FXS Voice Interface Module
• Cisco VIC3-4FXO Voice Interface Card