multicast routing

Multicast routing delivers source traffic to multiple receivers without any additional burden to the source or the receivers. Multicast packets are replicated in the network by routers that are enabled with PIM, which results in the efficient delivery of data to multiple receivers.

Multicast routing is based on an arbitrary group of receivers that expresses an interest in receiving a specific data stream. The group does not have physical boundaries—the hosts can be located anywhere on the Internet. The hosts must join the group using IGMP to receive the data stream.