There is provided a method of coupling a switched circuit network and an internet protocol network. The switched circuit network and the internet protocol network are interconnected by a gateway. The gateway comprises a database. The switched circuit network comprises a service which is identified by a service identifier. The internet protocol network comprises a group of application servers and the group of application servers comprises at least one application server. Each of the at least one application server are identified by a specific application server identifier. The method comprises the step of generating an entry in the database in response to a service call requesting the service if the service call is routed to an available application server, wherein the service call is received from a calling party located on the switched circuit network, and wherein the available application server is comprised in the group of application servers. The entry comprises the service identifier, the specific application server identifier of the available application server, and a timestamp. The method further comprises the step of deleting the entry after a given period of time has been spent with respect to the timestamp. The method further comprises the step of sending a control message to a calling party in response to the service call if the service call is routed to an unavailable application server and if only the specific application server identifier of the unavailable application server is comprised in the database or if the service call is routed to an unavailable application server and if all application servers of said group of application servers are unavailable and if the specific application server identifiers of all application servers of said group of application servers are comprised in the database.