Com21 Joins Other Industry Leaders in PacketCable Interoperability Initiatives.

MILPITAS, Calif.--(BUSINESS WIRE)--July 8, 1999--

-- Industry leaders are developing standards for delivery of

advanced services over cable infrastructure --

Com21, Inc. (Nasdaq:CMTO) today announced that it has joined with other industry leaders to further the development of interoperability interface standards for delivering advanced services over the cable infrastructure.

The Company participated in the first of a series of interoperability tests hosted by CableLabs(R) for PacketCable(TM). Also participating in the first interoperability tests were: 8x8, Arris, HotHause & Telogy, Clarent, IPCell, NetSpeak, Telcordia, Hewlett Packard and Catapult Communications.

PacketCable(TM) is a fast-track initiative to develop interoperable interface specifications for the delivery of a wide range of multimedia services over two-way cable plants. Built on top of the industry's highly successful cable modem infrastructure, PacketCable(TM) networks will use Internet protocol (IP) technology to enable applications such as IP telephony, multimedia conferencing, interactive gaming, and general multimedia applications.

"The industry is moving aggressively toward implementation of products which utilize PacketCable specifications," said John Pickens, Ph.D, vice president of Technology and Chief Technical Officer, Com21. "We have always been a leader in the development of advanced service technologies and are pleased to be one of the first broadband systems suppliers to be active in this development and interoperability testing effort."

According to Mehdi Asgharzadeh, general manager, DOCSIS Business Unit at Com21, "Com21 is extremely excited with its participation in the first PacketCable interoperability event. Our contribution readily highlights the Company's solid commitment toward the CableLabs and PacketCable efforts to create industry-wide standards."

"This emphasizes our commitment and continuing leadership with regard to telephony and Voice over IP technologies," added Asgharzadeh.

Com21 is an approved vendor-author and active contributor in CableLab's PacketCable, packet voice/video-over-cable interface specification project.

About Com21, Inc.

Com21, Inc., is a leading global provider of system solutions for the broadband access market. The Company's DOCSIS and ATM-based products enable cable operators and service providers with the abilities to deliver high-speed, cost-effective Internet and telephony applications to corporate telecommuters, small businesses, home offices and residential users.

Com21 was recently named "The Fourth Fastest Growing Public Company in Silicon Valley for 1998," based on percentage growth from 1996 to 1998, by The San Jose and Silicon Valley Business Journal.

Founded in 1992, Com21 stock is publicly traded on Nasdaq under the symbol CMTO. The ISO 9001 certified company is headquartered in Milpitas, California, USA, and maintains domestic and international sales and support locations in the United States and Canada, Europe, Asia, Latin America.

About CableLabs(R)

Founded in 1988, Cable Television Laboratories, Inc. (CableLabs(R)) is a membership organization consisting of cable television system operators serving cable subscribers in the U.S., Canada, Mexico, and South America. It was established with the goal of ensuring that technology is made practical and accessible to the cable television industry in a timely fashion. Its mission is to plan and to fund research and development projects; to transfer relevant technologies to member companies and industry suppliers; and to serve as a clearinghouse in providing technological information to its members.

Safe Harbor Act Clause

This press release contains forward-looking information within the meaning of Section 27A of the Securities Act of 1933 and Section21E of the Securities Exchange Act of 1934, and is subject to the safe harbors created by those sections. Actual results may differ materially due to a number of factors, including Com21's continued contribution and participation in the CableLabs and PacketCable interoperability initiatives, including numerous technological, operational and financial challenges associated with deploying, manufacturing, marketing distributing and servicing broadband products. The matters discussed in this press release also involve risks and uncertainties concerning Com21's products and services described in Com21's filings with the Securities and Exchange Commission (SEC). In particular see the risk factors described in the Company's Form 10K for the fiscal year ended December 31, 1998, and Form 10Q for the fiscal quarter ended March 31, 1999. Com21 assumes no obligation to update the forward-looking information contained in this press release.

Com21, Inc.,(R) is a registered trademark or trademark of Com21, Inc., Milpitas, California, U.S.A. All other brands are trademarks or registered trademarks of their respective owners.