Patent ID: 6992974

Claim:
A proxy server for providing fault tolerance in a network telephony system, comprising in combination: a receiver operable to receive a first signaling message from a first network entity via a network, wherein the first signaling message is transmitted from the first network entity to initiate a call with a second network entity; a transmitter operable to transmit a second signaling message to the second network entity via the network to initiate the call with the second network entity; an address resolver operable to determine the second network entity to which the second signaling message is to be transmitted; and an assembler operable to modify the first signaling message to obtain the second signaling message by adding at least a path attribute including at least one network address corresponding to a backup proxy server such that the second signaling message used to initiate the call with the second network entity includes the at least one network address corresponding to the backup proxy server.