Patent ID: 7486612
Filing Date: 2009-02-03
Classification: H04L

Abstract:
1. A network comprising: a first router having a plurality of interfaces that include a first interface and a second interface, the first interface having a connection to receive multicast data packets from a first medium and transmit multicast data packets to the first medium, the first interface to receive multicast data packets output by a source router from the first medium, and transmit no multicast data packets to the first medium unless the first interface is unable to receive multicast data packets output by the source router from the first medium, the first interface to receive a back-up mode packet when the first interface is unable to receive multicast data packets output by the source router from the first medium, the second interface to forward multicast data packets received by the first interface from the first medium to the second medium, and forward the back-up mode packet received by the first interface to the second medium, the second interface to receive no multicast data packets from the second medium until after the back-up mode packet has been forwarded; and a second router having a plurality of interfaces that include a third interface and a fourth interface, the second and third interfaces being connected together via a second medium, the first medium and the second medium being segments of a single ring, the third interface to receive multicast data packets and the back-up mode packet from the second medium, the third interface to forward no multicast data packets to the second medium until after the back-up mode packet has been received, the fourth interface to receive no multicast data packets from a third medium until after the back-up mode packet has been received.