No Audio if softphone outside of LAN

[rosetown]

I am having an issue with audio not working when the softphone is located outside of the same LAN as the vicidial server.

Network Topology: Modem > (68.X.X.X) Airport Extreme Router > (10.X.X.X) Vicidial Server
I have forwarded TCP/UDP 5060, 5080 and UDP 10000-25000 to the Vici server.

If I connect via SIP to the Vicidial Server from WITHIN the same LAN, phone rings, calls work fine, audio both directions

If I connect via SIP to the Vicidial Server from OUTSIDE the LAN, the phone rings, but there is no audio either way

If I connect via IAX2 to the Vicidial Server from OUTSIDE the LAN, there is audio but with a >3 second delay


Is there some settings I need to change in order to allow "external agents"? Any ideas?

[hostcomm]

Hi
If you need a quick fix....change the router.
IAX2 is better at nat traversal which is why it connects albeit with a 3 second delay. It looks like RTP is getting blocked which shouldn't be happening if you set up an RTP port forward.
If you are prepared to spend a few hours finding the problem try the Apple forums, there are lots of references to port forwarding not working with this router.