Patent ID: 8774178
Filing Date: 2014-07-08
Classification: H04L,H04M

Abstract:
1. A method comprising the steps of: in a communication network wherein a first call is established between a first user device and a second user device via a first server, and the second user device, wishing to initiate a call transfer to a third user device, establishes a second call between itself and the third user device via a second server and upon the first server receiving a call transfer request from the second user device such that the first user device and the third user device can communicate, determining whether the first server has information that matches the second call; and upon determining that the first server does not have information matching the second call, sending a message from the first server, which is routed to the second server, so as to obtain information from the third user device such that the first user device and the third user device can communicate via the first server, wherein the message sent from the first server and routed to the second server indicates that the call transfer request was referred by the second user device; wherein sending the message from the first server comprises sending an invite message to a call session control function (CSCF) server so as to enable the CSCF server to route the invite message to the second server, the invite message comprising a Replace header field identifying the second call, a Referred-By header field indicating that the call transfer request was referred by the second user device, and media information of the first user device.