The MBG is nat'd from its external public ip address to the internal DMZ address.
I have opened ports according to mitel spec, the teleworker handsets authenticate and i can dial internal numbers. The problem is i can only receive one way audio i.e. the teleworker can hear the internal LAN phone but the internal LAN phone cannot hear the teleworker audio.
I suspect it is down to a routing issue with ASA but have hit i brick wall as to what the issue can be.
setup as is:
Teleworker DMZ IP 192.168.11.2
Teleworker outside external IP 86.188.xxx.xxx static NAT to 192.168.11.2
MCP IP 192.168.13.2 on voice LAN static NAT to DMZ