Patent ID: 7180863

Claim:
An overload control method for use in a multi-branch Internet Protocol-based private branch exchange system within a network environment having a primary network and at least one alternate network, said method comprising the steps of: maintaining a congestion indicator status associated with each path in said primary network, said congestion indicator status indicating whether said path is congested and based on congestion data from at least one end unit device that participated in a packet telephony communication; receiving a call set up request from a source terminal; determining if a primary path between said source terminal and a destination terminal is congested using said congestion indicator status; routing said call using said at least one alternate network if said primary path between said source terminal and a destination terminal is congested; and setting a timer that will cause said congestion indicator status to automatically expire after a predefined period of time, wherein said congestion indicator status and said timer are reset each time said congestion data is received from said at least one end unit device and wherein said timer expires after a period of time within which said congestion is expected to be alleviated.