Reliable multicast: when many must absolutely positively receive it

Multicasting enables a group of hosts to communicate and share the information simultaneously. IP multicast technology allows the underlying IP network to transport a copy of the sending host´s information to all members of the group, which can range in size from a few hosts to several thousand. Members of a multicast group are identified by a single group address rather than by their individual host addresses. The paper discusses the basics and the challenges facing IP multicast. It then focuses on reliable multicast issues