TOKYO, JAPAN — December 19, 2002 —OPNET Technologies, Inc. (Nasdaq: OPNT) the leading provider of Intelligent Network Management software, today announced that its partner, E3 Networks (owned by Mitsui & Co.) has completed OPNETWORK2002 Tokyo with record attendance from the enterprise IT community in Japan.

Held on December 16th in Tokyo, this event focused on OPNET's latest software and methodologies. Approximately 200 attendees, mainly from the IT departments of large Japanese corporations and system integrators, participated in 9 sessions organized in 3 parallel tracks focusing on application, server, and network performance.

Taro Ishiguro, President of E3 Networks Ltd., explained, "Japanese businesses are faced with one of the worst economic recessions in history, leading to especially tight IT budget constraints, and a requirement to do more with less... exactly the challenge OPNET's technology was designed to address. We are confident OPNET's IT Guru solutions will be incorporated into best practice methodologies for enterprises here, as they have already started to do in the USA, and in line with what the top industry analysts are recommending."

Featured speakers at OPNETWORK2002 Tokyo included:

Mr. Tetsuya Sakai, Senior Systems Engineer at Microsoft Japan, presented a case study showing how OPNET IT Guru was used to optimize the performance of a Microsoft.NET rollout at Mitsui & Co.

Mr. Hironobu Tamaki, Chief Operating Officer of Golf Digest Online, presented a cased study showing how an IT Guru and ACE analysis solved a critical performance problem for Golf Digest's web-based business, and helped him avoid unnecessary upgrades that were recommended to him by system integrators.

Mr. Kenji Higashi, Senior Consultant of Kanematsu Electrics Ltd., shared three case studies that featured OPNET solutions to his clients' problems, including a Citrix MetaFrame deployment at an electronics company, a 3D CAD application deployment at an engineering company, and a server relocation analysis for a large Japanese enterprise.

Mr. Nobuhiro Nishiguchi, President & CEO of D.A.T.S. Co. Ltd., introduced his company's new OPNET-based service and shared a case study of a successful application troubleshooting project at a large Japanese pharmaceutical company.

Mr. Todd Kaloudis, Vice President of Business Development & Marketing at OPNET, shared IT trends from the United States, and explained OPNET's vision for Intelligent Network Management.

Johokobo Corporation, an OPNET reseller and services company, provided demonstrations of OPNET's scalable network modeling & simulation technology for Japanese government and defense organizations.

"We are pleased with the turnout at OPNETWORK2002 Tokyo,"stated Joseph Lenz, Vice President of International Sales at OPNET. "Our partners and customers in Japan did an outstanding job replicating the excitement of the OPNETWORK2002 event we hosted in Washington, D.C. last August. I was especially encouraged by the detailed case study presentations that illustrated success with OPNET's technology from both business and technical perspectives."

About E3 Networks
Mitsui & Co. established E3 Networks, Ltd. (E3) as a strategic subsidiary specializing in IT management software and services on April 1st, 2001. E3 is OPNET's leading distribution partner outside of the USA, and is also HP's top-selling distribution partner in Japan for the HP OpenView Network Node Manager solution.

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About OPNET Technologies, Inc.
Founded in 1986, OPNET Technologies is the pioneer and leading provider of Intelligent Network Management software. For more information about OPNET and its products, please visit www.opnet.com.

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IT Guru, OPNETWORK, and OPNET are trademarks of OPNET Technologies, Inc. All other trademarks are the property of their respective owners.

Statements in this press release that are not purely historical facts may constitute forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995. OPNET Technologies, Inc. ("OPNET") assumes no obligation to update statements. Forward-looking statements are predictions based upon information available to OPNET as of the date of this press release and involve risks and uncertainties; therefore, actual events or results may differ materially. For a discussion of risk factors, see OPNET's reports, including its most recent 10-Q and 10-K, filed with the Securities & Exchange Commission.

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Note to editors: The word OPNET is spelled with all upper-case letters.

OPNET Media Contact:
Margarita Castillo
OPNET Technologies, Inc.
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Mel Wesley
OPNET Technologies
(240) 497-3000
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www.opnet.com