System, mobile communications unit, and softswitch method and apparatus for establishing an Internet Protocol communication link

A softswitch for use in combination with a circuit network and a packet network, comprising:

• a packet network interface operably coupled to the packet network and that receives a first message from the packet network seeking to facilitate packet-based communications with a mobile communications unit, which mobile communications unit is compatible with both the circuit network and the packet network;
• a circuit network interface operably coupled to the mobile communications unit via the circuit network;
• a logic unit that is operably coupled to the packet network interface and the circuit network interface, wherein the logic unit has a first mode of operation pursuant to which the logic unit provides a communication to the mobile communications unit via the circuit network in response to the first message, which communication comprises an instruction to cause the mobile communications unit to automatically initiate setup of a communications link via the packet network.

A method comprising:

• receiving a first communication from an Internet Protocol network indicating a need to establish an Internet Protocol network communication link with at least one particular mobile communications unit;
• sourcing a second communication via a circuit network to the at least one particular mobile communications unit, which second communication includes at least one instruction to cause the at least one particular mobile communications unit to automatically initiate setup an Internet Protocol network communication link with the Internet Protocol network.

The method of 31 wherein the notification of the presence of the at least one particular mobile communications unit in the Internet Protocol network is sent by the presence server using the Internet Protocol.