US Patent 7738445 Combined H.450.2 and SIP call transfer

A method for supporting advanced features in a core SIP network when the calling party is in a network operating with the H.323 protocol is disclosed. Specifically, after processing the calls by collecting information associated with the advanced features, a REFER message is sent by an application server to an ingress border element associated with the calling party. The ingress border element then sends an H.450.2 FACILITY message containing the information in the SIP REFER message to an application gateway associated with the calling party. Upon receiving a SETUP message from the application gateway, the ingress border element then translates that SETUP message into a SIP INVITE message to establish the call.