| 摘要 |
<p>The invention concerns a 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). The method comprises the steps of a) storing by the router (R3) in a memory a relation between a value of a receiver update notification (RUN 1 ) and a predefined construction set (CS1), the predefined construction set (CS1) includes a set of next hops that includes one or more next hops (R6, R7) being determined according to local unicast routing information for each destination of a predefined set of destinations (D4, D5, D8). The predefined set of destinations (D4, D5, D8) only includes these destinations of the plurality of destinations for which the router (R3) is on a path to these destinations; and b) associating by the ingress node (N1) to a starting destination set (D1, D2, ..., D8) the value of the receiver update notification (RUN1) and including by the ingress node (N1) the value of the receiver update notification (RUN1) in the multicast packet (P); and c) by the router (R3), upon reception of the multicast packet (P) that includes the value of the receiver update notification (RUN1), determining a predefined subset of destinations (D4, D8) and determining for the predefined subset of destinations (D4, D8) a next hop (R6) of the set of next hops (R6, R7) according to the value of the receiver update notification (RUN 1) and according to the relation to the predefined construction set (CS1). The predefined subset of destinations (D4, D8) and the value of the receiver update notification (RUN1) are included in the new multicast packet (P) and the multicast packet (P) is forwarded towards the next hop. The predefined subset of destinations (D4, D8) includes these destinations of the plurality of destinations for which the next hop (R6) is on a path to these destinations. <IMAGE></p> |
