I was a problem when wanting to communicate telephony between two routers 3925, on both routers and I have configured the
telephone service (telephony-service), I have discharged my phone and there are internal communication in each of them (I can make
between phones of the same router), every router I've configured a dial-peer intercomunicarlos and this is where the problem arises. When I try to dial a phone in the router A to each router B the phone dials the Ringout timeout and mark Unknow number is completed, when I make a call, the router which owns the phone number of that mark, I run the sh voice call status command and indicates to me that there is a call in progress and you're using it, the dial-peer problem is that it seems that the other router you never call arrives.
I help a lot to have an overview of why this happens.