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September 15, 1997

Nascent technology could reduce push bandwidth

A small company is on the verge of receiving a U.S. patent for a new technology that can reduce by as much as 90 percent the bandwidth required for Internet push services.

The company, called Kangaroo, is based in Seattle and its technology is called Punch. (The term Punch distinguishes the new software from what two of the company's executives, David Campbell and Roland Faragher-Horwell, consider highly inefficient push software.)

Push technology, of course, is all the rage today. In a typical push scenario, information is sent across the Internet on a regular basis from a central server to hundreds or thousands of subscribers. The information ranges from broad subjects, such as daily news feeds, to data important only to a single company, such as internal engineering manuals that must be kept updated.

Problems arise due to the enormous bandwidth that push technologies can require when feeding data to thousands of end-users. If the PCs in a given subscriber base must poll a central server on a regular basis to see whether there is any new information, the number of packets needed to handle these requests can get very high. And most of today's push technologies require that an entirely new file be sent across the Internet, rather than sending only the few bytes that have changed since the last update.

Kangaroo's Punch technology is based on a completely different model. Until now, updating information from a central source relied on a star topology: A central server sends data out to each recipient in turn. Imagine the spokes radiating out from the hub of a wagon wheel: The server is at the center, and the clients are at the ends of the spokes.

Instead of the inefficient star model, Punch distributes information by "osmosis." Once information is changed in an electronic document, each PC subscriber receives the new information and passes it along to other PCs in the same group.

Kangaroo's software identifies other PCs that are nearby (electronically speaking) and are also part of its "cohort." A server can send new information to any member of a cohort, and the recipient will send it along to other responsive members, which can be on a LAN or the Internet. The software sends a query to other cohort members the first time it is started each day. This start-up query is much less bandwidth-intensive than polling but keeps each client up to date.

On a network of Windows 95 PCs using Punch, a 1-byte change in a 500KB file is automatically communicated to other members of a cohort using only 46 bytes of data. Typical push software requires resending the entire file to communicate the same change.

Kangaroo's new technology can radically reduce the amount of bandwidth needed by companies to send updates to large numbers of end-users. Everything from corporate price lists to global news services can be updated by osmosis, rather than using time-consuming centralized distribution.

Kangaroo has been notified that its patent application has been allowed, the final step before actual issuance. The technology is not a shrink-wrapped product yet, but Kangaroo is working with VARs and software distributors to put it in everything from e-mail clients to database applications.

What little information is currently available on this technology may be found at You can't buy Punch software in a computer superstore today, but you'll be hearing much more about this breakthrough in the coming months.

Brian Livingston is the co-author of Windows 95 Secrets and four other Windows books (IDG Books). Send tips to or fax: (206) 282-1248.

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Copyright © 1997 by InfoWorld Publishing Company


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