Cisco::VOIP::Delay establishing call
Sometimes it take 5-10 seconds for both parties of a call to hear each other.
This is because the RTP channel comes up after the source router receives a connect message from the destination router. The connect message is sent after the person being called picks up the phone.
At the router, input the following:
ROUTER(config)#voice rtp send-recv
This will make all calls establish the voice path in both directions before a connect messagee is received from the dest switch.