Abstract: A method of operating a network node in PIM-SM (Protocol Independent Multicast-Sparse Mode) is disclosed. In one embodiment, a Rendezvous Point Tree (RPT) to Shortest Path Tree (SPT) switch over process is initiated after the packet flow rate of the RPT data stream is compared against a predetermined threshold using a reverse rate limiting technique. If the packet flow rate of the RPT data stream exceeds the threshold, further analysis can be performed to decide whether the RPT to SPT switch over process should be initiated. Otherwise, if the packet flow rate does not exceed a predetermined threshold, the network node continues to receive multicast packets via the RPT until the predetermined threshold is reached.

Abstract: An efficient Reverse Path Forwarding (RPF) check mechanism is disclosed. In one embodiment, when a network node receives a multicast packet on an incoming interface, the network node obtains an expected incoming interface identifier from either a unicast routing table or a multicast forwarding information table. A RPF Flag stored in association with multicast flow information determines from which table the interface identifier is obtained. If the expected incoming interface does not match the actual incoming interface, the multicast packet is discarded.

Abstract: An efficient Reverse Path Forwarding (RPF) check mechanism is disclosed. In one embodiment, when a network node receives a multicast packet on an incoming interface, the network node obtains an expected incoming interface identifier from either a unicast routing table or a multicast forwarding information table. A RPF Flag stored in association with multicast flow information determines from which table the interface identifier is obtained. If the expected incoming interface does not match the actual incoming interface, the multicast packet is discarded.

Abstract: A method of operating a network node in PIM-SM (Protocol Independent Multicast-Sparse Mode) is disclosed. In one embodiment, a Rendezvous Point Tree (RPT) to Shortest Path Tree (SPT) switch over process is initiated after the packet flow rate of the RPT data stream is compared against a predetermined threshold using a reverse rate limiting technique. If the packet flow rate of the RPT data stream exceeds the threshold, further analysis can be performed to decide whether the RPT to SPT switch over process should be initiated. Otherwise, if the packet flow rate does not exceed a predetermined threshold, the network node continues to receive multicast packets via the RPT until the predetermined threshold is reached.