Com21's DOCSIS Modems are Cisco Interoperable; Com21 DOXport Cable Modem Compatibility Verified as Cisco Interoperable.

MILPITAS, Calif.--(BUSINESS WIRE)--April 29,1999--

Com21, Inc., (Nasdaq:CMTO), a leading supplier of broadband access solutions, today announced that its new DOXport(TM) DOCSIS cable modem has successfully passed interoperability testing with the Cisco Systems' Universal Broadband Router (uBR).

As part of the Cisco Interoperability Partner program, both companies have been jointly testing their DOCSIS products. The Com21's DOXport cable modem (v 1.0.0.033) was tested against the Cisco uBR7246 (v k1p-mz.113) at the Cisco test facilities in San Jose, California. Cisco's uBR7246 has been qualified as DOCSIS compliant by CableLabs(R).

Ken Gorman, vice president of engineering and general manager of the DOXport Business Unit at Com21, said, "This is a great milestone for Com21, and we are extremely pleased to achieve interoperability with Cisco's DOCSIS-qualified Universal Broadband Router. Multi-vendor compatibility is mandatory to accelerate the continued growth of standards-compliant products in this expanding DOCSIS market."

About Com21, Inc.

Com21, Inc. is a leading global provider of broadband access solutions for delivering high-speed Internet access over CATV systems. The company's products enable cable operators and service providers with the abilities to provide high-speed, cost-effective Internet access to corporate telecommuters, small businesses, home offices and residential end-users.

Com21 is ranked as the No. 1 cable modem supplier in Europe based on a 1998 survey conducted by California-based market research firm RHK Com21 is the third largest supplier of cable modem technology worldwide with 126,000 modems shipped through 3/31/99, based on independent market research studies conducted by GartnerGroup's Dataquest (1H'98), The Dell'Oro Group, and Cahner's In-Stat Research Group. Com21 ComPORT(R) cable modems are commercially deployed worldwide with over 9.8 million households passed.

Founded in 1992, its stock is publicly traded on NASDAQ under the symbol CMTO. The ISO9001 certified company is headquartered in Milpitas, California, USA, and maintains international sales and support locations in Canada, Europe, Asia, and South America. For more information, visit the Com21 web site at www.com21.com.

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. 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). These forward-looking statements include statements related to: the ability of Com21's products to continue to meet the compatibility testing standards of Cisco's CMTS product. Actual results may differ materially due to a number of factors, including numerous technological changes, software revisions and hardware changes associated with developing, manufacturing, marketing, distributing and servicing broadband products. In particular see the risk factors described in Com21's Prospectus dated pursuant to Rule 424(b) of the Securities Act of 1933 dated February 23, 1999, and the Company's Form 10K for the fiscal year ended December 31, 1998. Com21 assumes no obligation to update the forward-looking information contained in this press release.