Just-in-time call registration for mobile call to voip device

A method for establishing a voice session between a mobile device and a VoIP device, comprising:

• receiving a request from a caller using a mobile device through a mobile data network to initiate a voice session with a callee using a VoIP device, the request including at least a virtual identifier associated with the callee, and a device identifier associated with the mobile device;
• creating a call registration record based on the request;
• receiving a telephone call from the mobile device through a mobile voice network, said telephone call including the device identifier for the mobile device;
• retrieving the call registration record based on the device identifier for the mobile device;
• notifying a VoIP device coupled to a VoIP network and having the virtual identifier associated with the callee regarding the voice session;
• and
• establishing the voice session via a mobile voice channel and a VoIP voice channel if the voice session is accepted by the callee.

A method for establishing a voice session between a telephone device and a VoIP device, comprising:

• receiving a telephone call from a telephone device through a telephone voice network;
• establishing a voice channel through the telephone voice network between the telephone device and a gateway;
• establishing a VoIP channel through a VoIP network between the gateway and an IVR system;
• sending a first voice prompt from the IVR system to the telephone device;
• receiving a response to the first voice prompt that identifies a callee for a proposed voice session;
• sending a second voice prompt from the IVR system to the telephone device asking for a personal identifier associated with the callee;
• receiving a response to the second voice prompt that includes the personal identifier;
• notifying the callee regarding the voice session;
• and
• establishing a VoIP channel through the VoIP network between the gateway and the VoIP device.