回復 6#kyecall
IAX client uses one port for registration and audio.
SIP client uses one port for registration and another RDP port for audio
Zoiper is the best client to use. It has both sip and iax.
If iax is ok, then it is most likely sip and NAT problem.
Also tell me your router model. Does it has sip client or ALG built in? It can interfere sip connection. My experience with Draytek router was an example.
I do have no real clue. Bubblestar said just usual setting. However, when I set up my brother dryatek router, I have tried various ways until it works.