I have an issue trying to transfer an external caller to Business Console to an external number, either direct or via speed dial. Calls fail with unassigned number. SIP trunks on both parts of call. Suspect it might be something to do with sending the originating Caller ID and Sip provider rejecting it. Any help would be appreciated.
It’s defiantly an interesting issue but I think you are headed in the right direction. I would test it with turning off the COS of echoing the original caller id to see the results. Has your Mitel partner been able to help?