Protocols and Applications
IP multicast is widely deployed in enterprises, commercial stock exchanges, and multimedia content delivery networks. A common enterprise use of IP multicast is for IPTV applications such as distance learning and televised company meetings.
Since multicast is a different transmission mode from unicast, only protocols designed for multicast can be sensibly used with multicast.
Most of the existing application protocols that use multicast run on top of the User Datagram Protocol (UDP). In many applications, the Real-time Transport Protocol (RTP) is used for framing of multimedia content over multicast; the Resource Reservation Protocol (RSVP) may be used for bandwidth reservation in a network supporting multicast distribution.
On the local network, multicast delivery is controlled by IGMP (on IPv4 network) and MLD (on IPv6 network); inside a routing domain, PIM or MOSPF are used; between routing domains, one uses inter-domain multicast routing protocols, such as MBGP.
A number of errors can happen if packets intended for unicast are accidentally sent to a multicast address; in particular, sending ICMP packets to a multicast address has been used in the context of DoS attacks as a way of achieving packet amplification.
Read more about this topic: IP Multicast