What defines the path from the source to the receivers in a multicast network?

The path from the source to the receivers in a multicast network is defined by a Source-Based Distribution Tree. This distribution tree is built specifically for a source and determines how multicast traffic flows from that source to all receivers in the multicast group. Each source will typically have its own distribution tree that connects to all clients interested in receiving the multicast stream, ensuring that data is efficiently delivered only to the necessary recipients.

The Source-Based Distribution Tree provides a direct path that optimizes the use of network resources by reducing unnecessary duplication of multicast packets. This method enhances the overall efficiency of multicast traffic, as receivers can join or leave the multicast group without impacting the overall routing structure significantly.

In contrast, while multicast routing protocols help facilitate the creation and maintenance of these trees by discovering network paths and topology changes, the tree itself is what determines the actual flow of data. Other options, such as the multicast forwarding table, maintain forwarding information but do not intrinsically define the paths. Similarly, the multicast domain pertains to the scope of the multicast operation but does not specifically outline the path taken by the multicast traffic.