Xerox NS-2260 - Manual (Page 14)

1.5.2 IP Multicast Function
Internet Protocol (IP) multicast is a bandwidth-conserving technology that reduces traffic by
simultaneously delivering a single stream of information to thousands of corporate recipients and homes.
Applications that take advantage of multicast include video conference, corporate communications,
distance learning, and distribution of software, stock quotes, and news.
IP Multicast delivers source traffic to multiple receivers without adding any additional burden on the source
or the receivers while using the least network bandwidth of any competing technology. Multicast packets
are replicated in the network by the devices supporting multicast protocols resulting in the most efficient
delivery of data to multiple receivers possible.
Multicast is based on the concept of a group. An arbitrary group of receivers expresses an interest in
receiving a particular data stream. This group does not have any physical or geographical boundaries - the
hosts can be located anywhere on the Internet. Hosts that are interested in receiving data flowing to a
particular group must join the group using IGMP. Hosts must be a member of the group to receive the data
stream.
IP Multicast address
IP Multicast addresses specify an arbitrary group of IP hosts that have joined the group and want to receive
traffic sent to this group. IP multicast addresses range from 224.0.0.0 through 239.255.255.255. This
address range is only for the group address or destination address of IP multicast traffic. The source address
for multicast datagrams is always the unicast source address.