Patent ID: 6347090
Filing Date: 2002-02-12
Classification: H04L

Abstract:
Method to forward a multicast packet (P) in a connectionless multicast system from an ingress node (N1) via a router (R3) to a plurality of destinations (D1; D2; . . . ; D8), characterized in that said method comprises the steps ofa) storing by said router (R3) in a memory a relation between a value of a receiver update notification (RUN1) and a predefined construction set (CS1), said predefined construction set (CS1) includes a set of next hops that includes one or more next hops (R6, R7) being determined for each destination of a predefined set of destinations (D4, D5, D8) according to local unicast routing information, said predefined set of destinations (D4, D5, D8) only includes these destinations of said plurality of destinations for which said router (R3) is on a path to these destinations; and b) associating by said ingress node (N1) to a starting destination set (D1, D2, . . . , D8) that includes each one of said plurality of destinations (D1, D2, . . . , D8) said value of said receiver update notification (RUN1) and including by said ingress node (N1) said value of said receiver update notification (RUN1) in said multicast packet (P); c) by said router (R3), upon reception of said multicast packet (P) that includes said value of said receiver update notification (RUN1), determining a predefined subset of destinations (D4, D8); and determining for said predefined subset of destinations (D4, D8) a next hop (R6) of said set of next hops (R6, R7) according to said value of said receiver update notification (RUN1) and according to said relation to said predefined construction set (CS1); and including in said multicast packet (P) said predefined subset of destinations (D4, D8) and said value of said receiver update notification (RUN1); and forwarding said multicast packet (P) towards said next hop, said predefined subset of destinations (D4, D8) includes these destinations of said plurality of destinations for which said next hop (R6) is on a path to these destinations.