Patent ID: 7586903
Filing Date: 2009-09-08
Classification: H04L

Abstract:
1. For use in a telecommunication network, an Internet Protocol (IP) multimedia subsystem, comprising: an IP switch capable of receiving Session Initiation Protocol (SIP) communications from an external IP network; a call application node capable of executing a plurality of service applications including a serving call session control function (S-CSCF) application and an application server (AS) application, wherein said IP switch routes SIP communications to said S-CSCF application; said S-CSCF application capable of receiving, from a first Voice over IP (VoIP) user via the external IP network and said IP switch, a communication that includes a request from the first VoIP user to transfer to a second VoIP user a VoIP call that is currently in progress between the first VoIP user and a third VoIP user, said S-CSCF application capable of recognizing that the received communication includes a SIP communication component but fails to constitute a communication permitted by SIP, and, in response to said recognizing, said S-CSCF application capable of modifying the received communication to include an Instant Messaging (IM) identifier and forwarding the modified communication to said AS application; and in response to said IM identifier in said modified communication, said AS application processing said modified communication as an Instant Message, wherein said AS application is capable of removing from said modified communication an identifier associated with the third VoIP user, said AS application capable of associating the removed identifier with a further identifier, said AS application capable of inserting said further identifier into said modified communication to replace said removed identifier and thereby produce a further-modified communication, and said AS application capable of forwarding the further-modified communication to the second VoIP user.