the dfe-550tx uses chip-level address filtering when implementing ip multicasting (defined in rfc 1112). this hardware-based implementation provides a huge performance increase over other interface cards. formerly, broadcast packets were used for multicasting, but they are a less than ideal solution for transmitting packets to groups. this is because broadcast packets reach every terminal on the network, creating undue traffic and occupying cpu time on all computers.

    ip multicasting is a much better way to send data to groups, especially since routers and even switches can filter packets so they only reach those stations that are part of the group. the dfe-550tx goes one step further by examining multicast packets on the card itself (rather than using the computer's cpu) and only accepting those packets for the group(s) in which the host belongs, thus conserving cpu utilization.

    this can be very useful since more and more multicast data, such as corporate messages to employees, stock quotes, video and audio conferencing, and database replication is transmitted on today's networks.

    ip multicasting can eliminate an organization's need to maintain parallel networks for voice, video and data.