Patent ID: 7898990
Filing Date: 2011-03-01
Classification: H04L,H04M,H04W

Abstract:
1. A method comprising: receiving a Session Initiation Protocol (SIP) Refer message for a conference call between a first device in a circuit-switched network and a second device in an Internet protocol (IP)-based network at a gateway device from the second device, the SIP Refer message including first address information associated with the first device, second address information associated with the second device, and third address information associated with a conference controller, wherein the first address information comprises a uniform resource indicator including a telephone number of the first device included in a Request field of the SIP Refer message; sending a first message to the first device from the gateway device; receiving a first response from the first device at the gateway device establishing a first call leg towards the first device based on the first address information; requesting a subscriber identity from the first device and checking the first address information based on the requested subscriber identity; sending a second message to the conference controller from the gateway device; receiving a second response from the conference controller at the gateway device establishing a second call leg towards the conference controller located in the IP-based network based on the third address information obtained from the SIP Refer message; and connecting the first and second call legs to form a single connection.