Patent ID: 7710889
Filing Date: 2010-05-04
Classification: H04L

Abstract:
1. A communication system which uses an IP network to support broadcast-type multicast packet communications, comprising: a distribution server which transmits a main multicast packet distributed in a broadcast format; a probe transmission server which transmits at fixed intervals of time a probe multicast packet distributed via the same path as the main multicast packet; a delay insertion server which receives the main multicast packet and the probe multicast packet, inserts same fixed delay time to both of the received multicast packets, and transmits both of the received multicast packets to the IP network; a backup server which receives the main multicast packet, generates two copied multicast packets by copying the received main multicast packet, and transmits one of the copied multicast packets as a synchronism backup multicast packet to the IP network, and in addition, inserts a fixed delay time to rest of the copied multicast packets and transmits as a delay backup multicast packet to the IP network; and a communication control apparatus which, when a communication break in the main multicast packet is detected, receives both the backup multicast packets from the IP network, uses the received backup multicast packets to generate a backup main multicast packet which is distributed via the same path as the main multicast packet, and transmits the backup main multicast packet to the IP network; the communication control apparatus receiving the probe multicast packet from the IP network and checking a communication condition of the main multicast packet based on a reception interval of the probe multicast packet.