New VoIP System Reliability

So as promised, the fun we had getting the reliability up and running. Little did we know when we first was trying to get our system set up to work with our ISP, that how we had it connected was interfering with the reliability. While trubbel shooting the problems, we noticed that there where two, codec and reliability. After we got the codec fixed, then it was all our fault for the reliability. We where running the dedicated VLAN from our ISP through our fire wall, pfSense. And that was our problem. Once a UDP session was initialized from the out side in, we had about 30 sec. after that call was done to call out over our ISP SIP trunk. Once that route was cleared, then the system didn't know how to establish the UDP connection to the ISP. So we just bypassed our firewall and now it works like it should.