Patent ID: 8446920

Claim:
A method for providing resilient digital telephony services for wireless communication devices, comprising: registering a plurality of wireless communication devices with a border gateway connected to a network comprising at least two telephony servers, wherein the border gateway is a back to back user gateway configured to receive session initiation protocol (SIP) messages from each of the plurality of wireless communication devices. terminate the SIP messages, and re-send the messages from the back to back user gateway; identifying a primary telephony server and a secondary telephony server from the at least two telephony servers for each of the plurality of wireless communication devices; communicating a heartbeat signal at a selected frequency between the border gateway and the at least two telephony servers to determine an operational status of the at least two telephony servers; and when a selected number of heartbeat signals are not communicated between the border gateway and at least one of the telephony servers, sending an instruction from the border gateway to the identified secondary telephony server to provide failover service for each of the plurality of wireless communication devices that are identified as using the at least one telephony server as the primary telephony server.