Patent ID: 6674853
Filing Date: 2004-01-06
Classification: H04L,H04M

Abstract:
A method for redirecting telephone calls by a central switching system via a wide area network where the central switching system retains call control over the redirected telephone calls and the central switching system having a switching network and each of a plurality of remote switches having an individual switching network and each individual switching network having a plurality of connected telephone sets, comprising the steps of:establishing by a first one of the plurality of remote switches one of a plurality of control channels for each of a first plurality of telephone sets connected to the first one of the plurality, of remote switches; determining a call origination by the central switching system by a first one of the first plurality of telephone sets via a first one of the plurality of control channels for the establishment of a first one of the telephone calls to a second one of the first plurality of telephone sets; establishing a first one of a plurality of bearer channels to the first one of the first plurality of telephone sets by the central switching system via the switching network of the central switching system and switching network of the first one of the plurality of remote switches; transmitting an alert message to the second one of the first plurality of telephone sets by the central switching system via a second one of the plurality of control channels; establishing a second one of plurality of bearer channels to the second one of the first plurality of telephone sets by the central switching system via the switching network of the central switching system and switching network of the first one of the plurality of remote switches; communicating the first and second ones of the plurality of bearer channels by the switching network of the central switching system and the switching network of the first one of the plurality of remote switches; transmitting a call answer message by the second one of the first plurality of telephone sets via the second one of the plurality of control channels to the central switching system; determining by the central switching system in response to the call answer message that the first and second ones of the first plurality of telephone sets can directly communicate bearer information; transmitting first and second path control messages to the first and second ones of the first plurality of telephone sets to directly communicate by the central switching system via the first and second ones of the plurality of control channels, respectively; and establishing a bearer connection between the first and second ones of the first plurality of telephone sets by the first one of the plurality of remote switches via the switching network of the first one of the plurality of remote switches in response to the first and second path control messages from the central switching system received via the first and second ones of the plurality of control channels.