Hi,

I have an SL2100 with 6 remote IP phones connected via a VPN. Calls into extensions at the site with the pbx work fine, as do external calls inbound and outbound

What we cannot do is make calls between extensions at the remote site, if we dial the extension we here the ringing dialtone but then when the extension picks up there is no audio and after 10 seconds the call is ended and the IP phone displays hang up

This is only happening on the internal calls between the extensions at the remote site,

In terms of the config for the phones they have

SIP 1st Server Address: internal IP of pbx
Access mode: Normal
SIP 1st Server Port 5080
NAT traverse Mode: Dynamic
WAN Mate IP: Internal IP of the PBX
WAN Mate Port: 5080

Could anybody let me know what may be going wrong?