I have an issue with call forwarding, if anyone else has had similar issues, suggestions for a fix, or any ideas I would be grateful.
Our MBG is in DMZ mode, our PBX is a 3300 on the internal LAN.
Calls are OK incoming and outgoing
However call forwarding fails
E.G. If I forward my DDI to my mobile, then ring my DDI from an external number, the call is transferred to my mobile. However when I answer there is no audio either side.
I understand this type of issue with no audio could be the result of NAT. We have a Palo Alto firewall. All firewall rules have been created as per BT guidelines for their SIP trunks with SIP ALG disabled.
Any assistance appreciated.
Thanks