Method for carrying out real-time backup communication of IP communication

摘要

Real-time communications are transmitted from a transmission side node 120 to a reception side node 130 via an internet protocol (IP) network 100 provided performance is deemed satisfactory. However if performance is deemed unsatisfactory the IP network is bypassed and the real-time communications are instead automatically diverted along a public network 110. If a real-time communication call is newly generated during the course of real-time communication on the public network then the newly generated real-time communication is made to go around the public network rather than the IP network. Performance is assessed by periodically transmitting echo test signals along the IP network. If the time interval between sending and receiving an echo test signal exceeds a predetermined allowed time interval then the quality of real time communication cannot be assured and performance is deemed unsatisfactory.