December 4, 1996 5:25 PM ET

Network Dispatcher clusters Web servers for efficient load balancing
By Eamonn Sullivan

  Fall Internet WorldThe technology used to manage the tremendous volume of traffic on World Wide Web sites such as those created for the 1996 Summer Olympics and the U.S. Open, French Open and Wimbledon tennis championships will be available for corporate networks by the end of this month.

IBM tomorrow will announce Network Dispatcher, which enables multiple Web servers to function as a single server to increase a site's reliability and performance. The software balances traffic among several Web servers, using an IBM-patented algorithm that ensures that requests are handled by the most responsive servers in the cluster, according to IBM officials.

The product, which will be demonstrated at Internet World next week, will be released Dec. 27 for IBM's AIX variant of Unix for $1,500 per Web server. A beta version is available now at

Versions of Network Dispatcher for Microsoft Corp.'s Windows NT and Sun Microsystems Inc.'s Solaris operating systems will be available in the first quarter of 1997. Versions for other operating systems (such as Hewlett-Packard Co.'s HP-UX) will ship later in the year, officials said.

"Network Dispatcher is primarily designed for a Web server environment to support a large amount of incoming traffic and to balance it appropriately," said Earl Mathis, a marketing manager in IBM's Internet Division. However, the product also can be used to cluster servers for other TCP/IP-based applications, such as FTP and Telnet, said Mathis.

In addition to the sporting events that IBM hosted, Network Dispatcher has been tested successfully on Netscape Communications Corp.'s Web site, which fields upward of 40 million hits per day, Mathis said.

IBM officials claim the software can handle as many as 4 million connections per hour and data rates well in excess of the capacity of a T-3 line to the Internet.

Network Dispatcher, the first product to be released as part of IBM's Web Object Management initiative, is entering an increasingly crowded market. Cisco Systems Inc. ( has a hardware-based product called LocalDirector that automatically balances TCP/IP traffic among several servers using a router. Two smaller companies, HydraWEB Technologies Inc. ( and Resonate Inc. (, offer software solutions for clustering Web servers.

Network Dispatcher holds its own against those products because it is less expensive and easier to use with a heterogeneous network of servers, Mathis said. The Web servers in the cluster served by Network Dispatcher can run any operating system and use any Web server software.

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