Patent ID: 8271691

Claim:
A method of coupling a telephone switched circuit network to an internet protocol network, said telephone switched circuit network and said internet protocol network being interconnected by a gateway, said gateway comprising a rules database, said rules database comprising a non-routing key rule, said method comprising the steps of: a) generating a control message for a service by use of said non-routing key rule, said service being located on said telephone switched circuit network, said service being implemented by at least one application server located on said internet protocol network, said at least one application server being specified by an application server status; wherein said service is implemented by at least two application servers, wherein in said non-routing key rule certain application servers of said at least two application servers are specified to be mandatory for said service, wherein said non-routing specified so that a first control message is generated if the application server status of each of said mandatory application servers is available and wherein said non-routing key rule is specified so that a second control message is generated if one application server status of one of said mandatory application servers is unavailable; b) sending said control message to at least one node, said at least one node being located on said telephone switched circuit network, wherein said non-routing key rule is configured to specify a plurality of application servers in various combinations that determine how the control message is generated, and c) sending said control message to all nodes located on said telephone switched circuit network if said application server status changes.