Abstract: A contact server receives a request to initiate an out-bound call to a recipient device. The request identifies the caller device by a cellular network phone number. The contact server establishes a communication link with the caller device and determines its associated data network phone number. The contact server establishes a link with the recipient device, indicating that the data network phone number is the source of call, and bridges the two links. The contact server may also receive a request for an in-bound call to a recipient device. The request identifies the recipient device by its data network phone number. The contact server establishes a link with the caller device and determines a cellular network phone number associated with the recipient device. The contact server establishes a link with the recipient device using its cellular network phone number and bridges the two links.

Abstract: A communication session between a first communication device and a second communication device is hosted in an Internet Protocol (IP) based packet data network. A contact server functions as a bridge service between the first communication device and the second communication device. A communication link between the first communication device and the contact server or the second communication device and the contact server is initially a voice-over IP (VoIP) communication link over a wireless data network. The contact server analyzes a call quality characteristic of the VoIP communication link and causes the communication device having the VoIP communication link to handoff the VoIP communication link from the wireless data network to a cellular communication link on a cellular network when the analyzed call quality characteristic of the VoIP communication link crosses a threshold level. Other embodiments describe handing off from a cellular communication link to VoIP communication link.

Abstract: A communication session between a first communication device and a second communication device is hosted in an Internet Protocol (IP) based packet data network. A contact server functions as a bridge service between the first communication device and the second communication device. A communication link between the first communication device and the contact server or the second communication device and the contact server is initially a voice-over IP (VoIP) communication link over a wireless data network comprised of a first packet data media stream. The contact server receives the first packet data media stream and at least one other packet data media stream from the first communication device and combines them into a single packet data media stream before transmitting the combined single packet data media stream to the second communication device.