US Patent 7206306 System and method for emergency call diversion

A distributed communication system that is capable of providing emergency call diversion during an event such as a power outage, network or sub-network failure, site closure, or the like, allows devices within the system affected by the event to rapidly inform one another that it is necessary to enter a call diversion state or mode during the duration of the outage. In this manner, calls may be diverted from different points within the network, or with different diversion behaviors as necessary.