Durchgangssystem zur Verbindung von Internet und Fernsprechnetz, und Steuerverfahren für Leitweglenkung

To detect network faults or congestion of traffic at an interface of a gateway system for connecting an If network and a telephone network on the side of the IP network and to allow the IP network to control alternative routing at the telephone network, network faults and congestion of traffic on the side of the IP network are monitored by the gateway system having an interface function between the telephone network and the IP network. When a network fault or congestion of traffic is detected, the gateway system notifies the telephone network upstream thereof of the disabled line and instructs the same to perform alternative routing, which makes it possible to prevent the occurrence of a situation in which the quality of communication at the interface between the telephone network and IP network can not be maintained.