Call handoff between subscriber's multiple devices associated with multiple networks

A system comprising a plurality of servers configured to:

• assign an identical unique identifier to each of a plurality of devices corresponding to a plurality of different networks, the unique identifier being associated with a subscriber associated with the plurality of devices;
• receive, by the centralized, packet-based network, a call associated with the unique identifier;
• route, by the centralized network, the call to a first device of the plurality of devices used on a first communications network of the plurality of networks;
• establish, by the centralized network, a call leg to a second device of the plurality of devices used on a second communications network of the plurality of networks;
• and
• route, by the centralized network, the call to the second device after the call leg is established.

A computer program product, tangibly embodied in an information carrier, for common telephony services for multiple devices associated with multiple networks, the computer program product including instructions being operable to cause data processing apparatus to:

• assign an identical unique identifier to each of a plurality of devices corresponding to a plurality of different networks, the unique identifier being associated with a subscriber associated with the plurality of devices;
• receive, by the centralized, packet-based network, a call associated with the unique identifier;
• route, by the centralized network, the call to a first device of the plurality of devices used on a first communications network of the plurality of networks;
• establish, by the centralized network, a call leg to a second device of the plurality of devices used on a second communications network of the plurality of networks;
• and
• route, by the centralized network, the call to the second device after the call leg is established.