Identify the line role and signaling before selecting a router voice module.
The practical distinction
FXO and FXS describe opposite roles on an analog connection. Digital T1/E1 and PRI add a different physical and signaling layer. A module with the right number of sockets can still be the wrong interface for the carrier or PBX.
What the product details tell you
- NIM-2FXO and NIM-4FXO provide FXO analog interfaces; they are not FXS subscriber ports.
- NIM-2MFT-T1/E1, NIM-4MFT-T1/E1 and NIM-2CE1T1-PRI require checking the exact digital interface and operating role.
- Voice service also depends on supported host software, DSP or PVDM resources, codecs and entitlements. Port count alone does not prove call capacity.
Applying it to a project
Inventory the carrier handoff, PBX role, signaling, grounding and simultaneous call requirement. Match the host and module, then size DSP resources for the codec and service. Schedule a staged migration with test numbers and rollback.
Checks that resolve the uncertainty
- Test inbound and outbound calls, signaling and caller identification as required.
- Exercise concurrent calls, fax or other contracted services.
- Record line settings, DSP resources, software and acceptance results.
Related products
Topic associations; verify the complete configuration before ordering.
- Cisco NIM-2FXO 2-Port Analog FXO Voice NIM
- Cisco NIM-2MFT-T1/E1 2-Port Multiflex T1/E1 NIM
- Cisco NIM-4MFT-T1/E1 4-Port Multiflex T1/E1 NIM
- Cisco NIM-2CE1T1-PRI 2-Port Channelized E1/T1 PRI NIM
- Cisco NIM-4FXO 4-Port Analog FXO Voice NIM