Multicast

Routing schemes
Unicast

Broadcast

Multicast

Anycast

In computer networking, multicast is group communication[1] where data transmission is addressed to a group of destination computers simultaneously. Multicast can be one-to-many or many-to-many distribution.[2][3] Multicast should not be confused with physical layer point-to-multipoint communication.

Group communication may either be application layer multicast[1] or network-assisted multicast, where the latter makes it possible for the source to efficiently send to the group in a single transmission. Copies are automatically created in other network elements, such as routers, switches and cellular network base stations, but only to network segments that currently contain members of the group. Network assisted multicast may be implemented at the data link layer using one-to-many addressing and switching such as Ethernet multicast addressing, Asynchronous Transfer Mode (ATM), point-to-multipoint virtual circuits (P2MP)[4] or InfiniBand multicast. Network-assisted multicast may also be implemented at the Internet layer using IP multicast. In IP multicast the implementation of the multicast concept occurs at the IP routing level, where routers create optimal distribution paths for datagrams sent to a multicast destination address.

Multicast is often employed in Internet Protocol (IP) applications of streaming media, such as IPTV and multipoint videoconferencing.

  1. ^ a b Media-communication based on Application-Layer Multicast
  2. ^ Lawrence Harte, Introduction to Data Multicasting, Althos Publishing 2008.
  3. ^ Li, Bing; Atwood, J. William (2016-06-19). "Secure receiver access control for IP multicast at the network level: Design and validation". Computer Networks. 102: 109–128. doi:10.1016/j.comnet.2016.03.010. ISSN 1389-1286.
  4. ^ M. Noormohammadpour; et al. (July 10, 2017). "DCCast: Efficient Point to Multipoint Transfers Across Datacenters". USENIX. Retrieved July 26, 2017.