Patent ID: 8204044

Claim:
A method performed by one or more network elements for establishing a voice-over-IP (VoIP) communications session between a first communication device and a second communication device, the method comprising: receiving a request from the first communication device to invite the second communication device to participate in a VoIP session, the second communication device being identified in the request by a network identifier; relating the network identifier to a mobile IP (MIP) address of the second communication device and a second IP address, the second IP address indicating either a point-of-attachment of the second communication device to a wireless access network or a care-of-address of a domain of the wireless access network in which the second communication device is located; sending an invitation to the MIP address of the second communication device, the invitation including a MIP address of the first communication device and a first IP address; receiving a response to the invitation from the second communication device; modifying the response to include a first IP header that includes the MIP address of the second communication device and a second IP header to include the second IP address; and forwarding the modified response to the first communication device, wherein after receipt of the modified response, the first communication device is configured to establish an IP connection for a VoIP session with the second communication device using the MIP address of the second communication device and the second IP address.