Patent ID: 8737397

Claim:
A method for converting a plurality of unicast sessions to a multicast session using Session Initiation Protocol (SIP), comprising: receiving, at a content server, a request by a client device for content available from the content server; in response to the request by the client device, determining whether a threshold number of unicast sessions exist for delivering the content to other client devices; and in response to a determination that a threshold number of unicast sessions exist for the content: establishing a multicast session for delivering the content, wherein the multicast session is established by the content server; generating a multicast session message for enabling the client device to join the multicast session, and propagating the multicast session message toward a SIP server configured to propagate the multicast session message toward the client device; and generating at least one multicast session join message for enabling the other client devices to join the multicast session, and propagating the at least one multicast session join message toward a SIP server configured to propagate the at least one multicast session join message toward the other client devices.