I am trying to find out if the Flash Media Gateway (an add-on for Flash Media Server that supports Telephony integration) is capable of supporting the SIP REFER verb. In the current environment we have set up, whenever a SIP REFER message is received by the gateway, the call ends up being dropped without anything of not showing up in the error logs.
I Finally received an answer from Adobe directly on this one:
Currently, Flash Media Gateway doesn't support receiving REFER and these are not included in allow header.