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

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. Performance is assessed by periodically transmitting echo test signals along the IP network using internet control message protocol (ICMP). 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. In this event either the IP network or the receiving side node must be behaving abnormally. An ICMP echo signal can be transmitted along the public network to determine if it is the IP network or the receiving side node which is behaving abnormally.