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...http://www.google.es/patents/US7738445?utm_source=gb-gplus-sharePatente US7738445 - Combined H.450.2 and SIP call transfer
