I am trying to setup a small network so that a handful of phones can communicate securely over a VPN. I have CUCME as my SIP server and it works just fine when they are all behind the same firewall. When the phones go out into the world and use a VPN to connect back to the network they can't send audio sometimes. I stood up a STUN server inside the firwall to help with the calls but not much of a difference. Out of 10 calls, maybe 1 will get perfect audio, then 3 will get one way audio in either direction, the 6 other times I get no audio. SIgnaling works, the phones ring everytime. but when I look at the network statistics there is a big 0 for anything received.
I have logs of the communication. if anyone cares to see.
