Com21 Demonstrates Unique Return Path Multiplexer at Cable '98; New Product Significantly Reduces Upstream Noise Funneling and Headend Capital Investment.

MILPITAS, Calif.--(BUSINESS WIRE)--April 20, 1998--Com21, Inc., worldwide cable modem system manufacturer, today announced that it will demonstrate the new Return Path Multiplexer (RPM) in its booth at Cable '98.

The RPM solves the HFC noise funneling problem and dramatically reduces headend capital investment for cable modem deployments.

Beta tests of the Return Path Multiplexer are scheduled to begin this quarter.

The live demonstration will consist of several return paths connected to an RPM which will be connected to a single Com21 ComCONTROLLER receiver, versus the typical configuration of one receiver per return path.

As a result, an operator with a large number of return paths can use one Com21 ComCONTROLLER to serve up to 96 return paths, thus reducing the amount of headend equipment required to deploy a cable data network.

The RPM employs intelligent multiplexing to only allow signals from one return path at a time to the ComCONTROLLER's receiver. Thus, noise from the remaining seven returns is blocked at the RPM. The RPM's high speed RF switching opens and closes to allow data to pass on whichever return path is required, but does not allow more than one to be open to the receiver at any given time.

Other Com21 Demonstrations at Cable '98

In addition to the new Return Path Multiplexer, Com21 will be demonstrating a variety of cable modem technologies in both the Com21 and partner booths.

Some of the new technologies Com21 will be showcasing include an MCNS prototype cable modem, Voice over IP (VoIP) technology, and the new entry-level ComCONTROLLER 2000. The MCNS prototype cable modem will be connected to a Cisco Universal Broadband Router (UBR) running an on-line gaming application.

Attendees will be able to place a call to anywhere in the world using voice over cable technology provided by Vienna Systems connected to Com21's Community Access system. The ComCONTROLLER 2000 is a compact version of the full-sized ComCONTROLLER and is functionally identical, housing the same, yet less, ComCONTROLLER modules.

In addition, Com21 is hosting an MSO forum where Com21 customers will be discussing their cable system, the applications they provide, and their data-over-cable pricing strategies. Throughout the show, speakers from various cable companies will present various topics such as how Com21 equipment has enabled them to improve the design of their data-over-cable systems and allowed them to increase revenue per subscriber.

In partner booths, Com21 will be in Cisco's booth exhibiting an MCNS solution and in the Microsoft booth demonstrating high-speed interactive gaming. Com21 equipment will also be showing in several booths, including @ Home and service provider Media City's ISP Channel.

Finally, Com21 will be participating in the new Cable Broadband Forum being launched at Cable '98 in Atlanta.

Com21 Inc., designs, develops, markets and sells value-added, high-speed communications solutions for the broadband access market.

The Company's ComUNITY Access system enables cable operators to provide high-speed, cost-effective Internet access to corporate telecommuter, small office/home office ("SOHO") and residential users in the U.S. and internationally, and enables them to address the distinct price, performance, security and other needs of these different end-user groups.

Com21's products include headend equipment, subscriber cable modems, network management software and noise containment technologies. -0-

Note to Editors: Visit Com21 at Booth No. 4790

www.Com21.com

CONTACT: Com21

Buck Gee, 408/953-9100

[e-mail]