Patent ID: 8213299

Claim:
A multi-site redundant telephony call processing system comprising: (a) an active telephony call processing host located in a first geographic region for controlling calls between telephony subscribers; (b) a standby telephony call processing host located in a second geographic region remote from the first geographic region for taking over call control functions handled by the active telephony call processing host in response to failure of the active telephony call processing host, the active and standby call processing hosts forming a single logical telephony call processing node; (c) a first local area network (LAN) including a first LAN segment and a second LAN segment being geographically distributed between the first and second geographic regions for carrying signaling messages to and from the active and standby telephony call processing hosts, wherein the first LAN is bridged over a wide area network (WAN) by interconnecting the first LAN segment located in the first geographic region with the second LAN segment located in the second geographic region using first and second routers that implement transparent bridging over the WAN; and (d) a second LAN including a first LAN segment located in the first geographic region and a second LAN segment located in the second geographic region, wherein the second LAN is a redundant LAN with respect to the first LAN, and wherein each of the first LAN and the second LAN respectively includes a single IP subnet, and wherein the active telephony call processing host is connected to both the first segment of the first LAN in the first geographic region and the first segment of the second LAN in the first geographic region and the standby telephony call processing host is connected to both the second segment of the first LAN in the second geographic region and the second segment of the second LAN in the second geographic region.