Core Issue
The components required to support analog Foreign Exchange Station (FXS) or Foreign Exchange Office (FXO) voice ports on the Cisco 2600, 3600 and VG200 series platforms include these options:
- Voice Network Module (NM-1V or NM-2V). This houses the FXS or FXO Voice Interface Card (VIC) and provides the Digital Signal Processing (DSP) functionality to digitize and compress analog calls.
- FXS or FXO VIC (VIC-2FXS, VIC-2FXO)
Resolution
The reason the 3600 router is not detecting the analog cards (VIC2-4FXO module) is that analog cards are not supported on NM-HDV. They are supported on the Voice Network Module (NM-1V or NM-2V).
For more information, refer to these documents: