Abstract: Multicast information flows are distributed from a source to user terminals over a network including aggregation routers arranged in hierarchical levels. Once a request for a given information flow is received from a user terminal, a distribution path can be defined through a plurality of aggregation routers. At one or more of the aggregation routers traversed by the information flow an information subflow can be derived to be propagated also towards lower-level aggregation routers that are not traversed by the information flow being distributed. Further requests for the same information flow received through an aggregation router towards which the information subflow was propagated are forwarded towards an aggregation router where the subflow was derived.

Abstract: Multicast signals are transmitted from a source to user terminals via multicast paths through a set of nodes in a network. A first node, such as a ‘last-hop’ router, may send toward the source corresponding join and prune messages, the join message to establish a new multicast path from the source to a user terminal, and the prune message to discontinue the old multicast path from the source to the user terminal. The router sends the join message and the prune message over the new multicast path and the old multicast path. A second node located at the bifurcation of the new multicast path and the old multicast path detects the reception of both the join message and the prune message and steers, either directly or via delegated downstream nodes, the switch from the old multicast path over to the new multicast path without loss or undue duplication of packets sent from the source to the user terminal.

Abstract: Multicast signals are transmitted from a source to user terminals via multicast paths through a set of nodes in a network. A first node, such as a ‘last-hop’ router, may send toward the source corresponding join and prune messages, the join message to establish a new multicast path from the source to a user terminal, and the prune message to discontinue the old multicast path from the source to the user terminal. The router sends the join message and the prune message over the new multicast path and the old multicast path. A second node located at the bifurcation of the new multicast path and the old multicast path detects the reception of both the join message and the prune message and steers, either directly or via delegated downstream nodes, the switch from the old multicast path over to the new multicast path without loss or undue duplication of packets sent from the source to the user terminal.

Abstract: Multicast information flows are distributed from a source to user terminals over a network including aggregation routers arranged in hierarchical levels. Once a request for a given information flow is received from a user terminal, a distribution path can be defined through a plurality of aggregation routers. At one or more of the aggregation routers traversed by the information flow an information subflow can be derived to be propagated also towards lower-level aggregation routers that are not traversed by the information flow being distributed. Further requests for the same information flow received through an aggregation router towards which the information subflow was propagated are forwarded towards an aggregation router where the subflow was derived.