Patent ID: 8526300

Claim:
A computer implemented method for a multicast edge network element guaranteeing resilient multicast traffic stream processing of only a last hop of the multicast traffic stream towards a multicast receiver, wherein the multicast edge network element is coupled with a first and second multicast core network element each capable of forwarding packets of an equivalent multicast traffic stream to the multicast edge network element and each is situated between a source of the multicast traffic stream and the multicast edge network element, comprising: separately joining through a first and second interface of the multicast edge network element the equivalent multicast traffic streams from the first and second multicast core network element respectively, wherein the equivalent multicast traffic streams have a same multicast source and multicast group; processing packets of the multicast traffic stream received at the first interface from the first multicast core network element, and while the first interface is receiving those packets uninterrupted, dropping packets of the equivalent multicast traffic stream received at the second interface from the second multicast core network element; and upon interruption of receipt of the packets of the multicast traffic stream at the first interface, transitioning to processing the packets of the equivalent multicast traffic stream subsequently being received at the second interface from the second multicast core network element; and after transitioning to processing the packets of the equivalent multicast traffic stream being received at the second interface from the second multicast core network element, performing the following, determining that a best route towards the source of the multicast traffic stream, according to a unicast routing protocol, is through a third multicast core network element, wherein the third multicast core network element is able to forward equivalent packets of the multicast traffic stream to the multicast edge network element and is situated between the source of the multicast traffic stream and the multicast edge network element, joining through a third interface of the multicast edge network element the equivalent multicast traffic stream from the third multicast core network element, and upon receiving packets of the multicast traffic stream on the third interface from the third multicast core network element, transitioning to performing the following, processing the packets of the multicast traffic stream received on the third interface from the third multicast core network element, and dropping the packets of the multicast traffic stream being received at the second interface from the second multicast core network element.