I have this problem where there is no audio when calling from remote extension (ata or GS Wave). A packet capture shows RTP packets going to the remote LAN IP address instead of the remote WAN IP address. I have read many threads having the same symptoms and I have tried most configuration scenarios/options, but the problem is still the same.
Right now, my setup looks like this :
Network method : switched (was routed before I gave switched a try)
External host : set
Local network address : set (of course, LAN subnet is different from remote LAN)
NAT on extensions : enabled (tried enabled/disabled)
RTP Ports : 10000-11000
I tried forwarding SIP and RTP ports from the firewall to the UCM but no RTP packets ever get to the firewall. The PBX works fine with local phones and the SIP trunk for external calls works fine as well. Since the PBX is in production, I can’t really mess with the options too much or reset it to factory defaults. This has to be something with the way the call is setup but I just can’t see it ! I tried setting up the external IP parameter on the remote ATA as well, but it didn’t work. The same ATA works flawlessly on an Asterisk PBX.