Patent ID: 8351355

Claim:
A method comprising: receiving a signaling message from a first end device to initiate a first call to a second end device, where the first end device communicates using an H.323 protocol and the second end device communicates using a SIP protocol; sending an invite message to the second end device using the SIP protocol; receiving, from the second end device, a SIP 3xx message that includes a calling number, called number and originally called number; determining, based on the received SIP 3xx message, that a call forward/redirection of the first call to a third end device is required, where an identifier associated with the third end device is included in the SIP 3xx message; determining interworking information needed for interworking between the SIP protocol and the H.323 protocol for the call forward/redirection of the first call, by reading the SIP 3xx message and identifying redirection fields in the SIP 3xx message that are used to generate a message in the H.323 protocol, wherein the redirection fields include information associated with an originator and a destination of the call forward/redirection and information associated with the identifier of the third end device; generating an H.450.3 message for the H.323 protocol using the redirection fields to associate the H.450.3 message with the signaling message from the first end device such that the H.450.3 message provides information to the first end device related to the call forward/redirection of the first call from the second end device to the third end device, wherein generating the H.450.3 message comprises interworking the calling number, the called number and the originally called number to a To field, a From field, and a Contact field in the H.450.3 message; sending the H.450.3 message to the first end device; receiving, from the first end device and in response to sending the H.450.3 message, a signaling message to initiate a second call to the third end device, where the first end device and the third device communicate using the H.323 protocol; and transferring signaling messages between the third end device and the first end device using the H.323 protocol to set up the second call.