Multicast

Multicast

Multicast is a the delivery of information to multiple destinations simultaneously. Typically used to refer to IP Multicasting, which is a protocol for efficiently sending to multiple receivers at the same time on TCP-IP networks, by use of a multicast address. It's also commonly associated with audio/video protocols such as RTP.

By comparison with multicast, conventional point-to-single-point delivery is called unicast[?].

There are two basic kinds of multicast delivery:

Modern multicast algorithms are often capable of combining and managing the two.

Multicast is not in general use in the commercial Internet, due to interoperability problems and the lack of a compelling business model for multicast.

However, some communities within the public Internet make regular use of multicast (see the MBONE[?] for an example), and multicast is used for special applications within private IP networks.

IP multicast protocols

Protocol independent multicast[?] (PIM)
Distance vector multicast routing protocol[?] (DVRMP)
Multicast OSPF[?] (MOSPF)
Multicast BGP[?] (MBGP)
Internet group management protocol (IGMP)