Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

MGCP No Audio

I have two 3845 routers that are being used as voice gateways  The IOS is version 12.4(13f).  I am connecting them to an Avaya PBX through T1 lines provisioned for ISDN.  I'm using MGCP and CUCM 6.  The module in slot 0 is listed as a NM-4VWIC-MBRD.  When I connect the devices through either port on a VWIC-2MFT-T1 in subunit 0 I can make everything work just fine.  The module in slot 3 is an NM-HDV2-2PORT-T1.  In subunit 1 there is an NM-HDV2-ONBOARD-T1-2PORT module listed.  On the router, I set up the T1 controller for that port, set up the voice port, and set up the serial port the same as the ports in slot 0.  On CUCM I set up everything just like the working ports.  However, if I make a phone call and use the lines in slot 3, the phone rings, I get called ID, but when I answer I get no audio.  The person making the call also hears no audio.  They don't even hear a ringback.


  • IP Telephony