Multicast is point-to-multipoint or multipoint-to-multipoint transmission. Use of multicast technology substantially reduces bandwidth usage and end-host processing requirements, since a single packet from the sender is duplicated only when paths to reach individual end sites diverge. The objective of NREN's multicast effort is to enable point-to-multipoint transmission for NASA applications. Multicast enhances network performance and increases the efficiency of the end host CPU efficiency.

NREN's activities in multicast include:

• Encourage deployment of multicast technologies across research networks and industry

• Operate a multicast exchange point

• Support NASA LANs, Fed Nets and Internet2 multicast implementations

• Collaborate with partners to standardize common protocol set

• Develop capability to monitor multicast applications

• Evaluate new multicast technologies as they emerge

• Educate application developers