To support analog voice ports, a Cisco MC 3810 series concentrator must be equipped with an Analog Voice Module (AVM). The AVM provides up to six analog voice ports with the Analog Personality Modules (APMs). Each voice personality module maps to a single analog voice port.
There are two types of Digital Signal Processor (DSP) modules for the 3810 series concentrators:
Voice Compression Modules (VCMs) can handle two calls per DSP channel.
High Compression Modules can handle up to four calls per DSP channel. You should not mix two types of DSPs on a single 3810 router.
For analog Foreign Exchange Office (FXO) or Foreign Exchange Station (FXS) ports, you need the APM-FXS or APM-FXO installed in the AVM. APMs are mounted on the top surface of the AVM.
For Cisco IOS Software on 3810 series concentrators, you need -a2isv5- or -a2jsv5- for VoIP or Voice over ATM (VoATM) features. You need -is for Voice over Frame Relay (VoFR) features.