Core Issue
To support analog voice ports, a Cisco MC3810 series concentrator must be equipped with an Analog Voice Module (AVM).
The AVM provides up to six analog voice ports with the Analog Personality Module (APM).
Each voice personality module maps to a single analog voice port.
These are two types of Digital Signal Processor (DSP) modules for MC3810s:
- Voice Compression Modules (VCMs) can handle two calls per DSP channel.
- High-Performance Voice Compression Modules (HCMs) can handle up to four calls per DSP channel.
Resolution
You should not mix two types of DSP modules on a single Cisco 3810 router.
For analog recEive and transMit (E&M) ports, you need the APM-EM (APM-E&M) installed in the AVM.
APMs are mounted on the top surface of the AVM.
For Cisco IOS Software on MC3810s, Voice over IP (VoIP) and Voice over ATM (VoATM) features, you need a2isv5- or -a2jsv5.
For Voice over Frame Relay (VoFR) features, you need -is.
For more information, refer to these documents:
