Patent ID: 6917819

Claim:
A controller for providing a subscriber database associated with a switch, said switch capable of handling call connections between calling devices and called devices on a plurality of trunk lines associated with said switch, and said switch capable executing call processing applications, wherein each of said call processing applications is associated with one of said call connections, said controller comprising: N call application nodes capable of executing a plurality of subscriber database server applications that connect a subscriber database to a call connection, wherein a first subscriber database server application is executed on a first one of said N call application nodes and is associated with a similar second subscriber database server application executed on a second one of said N call application nodes separate from said first call application node, said first and second subscriber database server applications thereby forming a subscriber database load sharing group server application, and wherein said each call processing application sends a subscriber database service request to said subscriber database load sharing group server application and said subscriber database load sharing group server application selects one of said first and second subscriber database server applications to perform said requested subscriber database service request according to a load distribution algorithm, and wherein said first subscriber database server application comprises a first primary-backup group server application that includes a first primary subscriber database server application executed on said first call application node and a first backup subscriber database server application associated with said first primary subscriber database server application, said first backup subscriber database server application residing on a call application node separate from said first call application node.