US Patent 7796643 Source and event based parameter determination

A call processing system in a destination network associated with a destination signaling protocol comprises an interface configured to receive first signaling for a call placed by a user from a device in a source network, wherein the first signaling indicates a source signaling protocol associated with the source network, and a processor configured to determine a status for the call, determine an event by which the status is conveyed to the user based on the status, determine a parameter based on the event and the source signaling protocol, and generate second signaling indicating the parameter.