Anyone Connected To The MBone?

The MBone (multicast backbone) is a collection of Internet routers that support the Internet Protocol (IP) multicast routing protocol. A network within a network, the MBone can carry live audio and video on the Internet. The multicast (i.e., one-to-many) aspect allows one computer to send the same data to many computers. Those helpful folks at the Internet Engineering Task Force created the MBone in 1993 to do videoconferencing on the Net.

Currently there are about 2000 MBone-using sites, and the MBone itself is doubling in size every six months or so. Some observers expect the originally experimental multicasting features to percolate Internet-wide by the turn of the century. The software itself is free and available for downloading.

So why doesn't everyone use the MBone for easy videoconferencing and easy listening? Possibly because you need a heavy-duty Unix workstation and a T-1 line to get started on video. A mere 56-Kbps line will do if all you're after is audio. But MBone eats bandwidth: An Internet backbone line that can handle millions of ordinary computer transactions, like E-mail, can carry only about 100 MBone sessions.

Still, you can find some interesting things on the MBone if you can pony up for the hardware. The London-based World Radio Network puts international shortwave broadcasts on line, for example. The House of Blues in Los Angeles broadcasts concerts. Sun Microsystems transmits its periodic Sunergy symposia for those without a satellite hookup.

You can find more information about the MBone (and the software needed) at http://www.best.com/prince/techinfo/MBone.html . Material about multicasting in general is at http://hill.lut.ac.uk/DS-Archive/MTP.html .