I'd highly appreciate if someone can shed some light on this challenge.
Call comes in from SIP service provider trunk to CUBE. CUBE passes the call to CUCM. CUCM finds the phone and recognize that call transfer to external location is configured (via same SIP trunk). At this point I'd like to configure CUCM and CUBE to use SIP REFER method instead of hairpinning the call back.
Does anyone know if it is possible? Many thanks!