Alcatel OXO External transfer issue

[jasonmenge]

Hi, I hope someone can help me with this external call transfer issue


Caller A dials inbound Via sip, and gets greeted by the Auto-Attendant on OXO. Caller A makes selection and gets routed to Caller B. Caller B makes outbound call to Caller C and attempts to do an attended transfer to C to bridge Caler A and Caller C. Call gets dropped on both end

Does anyone have some idea what i should be looking for

I have done alot of read up, some people say its the sip provider and some people say its pbx sip config issue