I've been fighting this issue for over 27 hours. When dialing sometimes audio is not hear on the receiving end and other times audio is not heard on the calling end. It appears audio is intermittent at best thus far in my setup. I'm running astersk and using VOIPo as a trunk. I also have several other SIP carriers in which I do not experience this issue at all. It seems VOIPo may be transmitting audio on ports I have yet to define within my firewall. Any insight as to the ports VOIPo is using beyond the standard 5060 SIP/10,000-20,000 RTP?

Thanks,

Chris