opnet
Press release

OPNET and CableLabs Deliver DOCSIS Bandwidth Modeling Software for Cable Networks

Software to Enable Manufacturers to Optimize Next-Gen Cable Modem Equipment and Service Providers to Deploy More Efficient Cable Network Infrastructures

WASHINGTON, DC - June 6th, 2001 -- OPNET Technologies, Inc. (Nasdaq: OPNT),the leading provider of intelligent network management software, today announced the industry's first DOCSIS 1.1 model for equipment and network design and planning.
The model, developed in conjunction with CableLabs'' Bandwidth Modeling and Management Vendor Forum, enables cable modem equipment manufacturers to test different product configurations and architectures before building expensive prototypes. It also allows cable operators to create virtual representations of proposed cable modem networks as they evaluate the capacity and quality of service (QoS) characteristics of alternative designs.

"DOCSIS technologies are poised to play a major role in next-generation cable networks and we're eager to continue supporting CableLabs' innovations for DOCSIS, " said Marc Cohen, CEO at OPNET. OPNET developed the DOCSIS 1.1 model for use with its Modeler, Guru, and Netbiz products. The OPNET DOCSIS 1.1 model is based on the DOCSIS 1.1 specification as established by CableLabs.

"We believe network modeling and management software will add significantly to the performance of cable infrastructures and will benefit cable operators by minimizing risks," said Dr. Terry Shaw, Director for Network Systems at CableLabs and the CableLabs staff member heading up the modeling forum.

Availability
The new DOCSIS 1.1 Specialized Model is expected to be available July 1, 2001 from OPNET. For pricing, contact info@opnet.com.

About OPNET Technologies, Inc.
Founded in 1986, OPNET Technologies, Inc. is the leading provider of intelligent network management software. The OPNET product suite combines predictive modeling and a comprehensive understanding of networking technologies to enable its customers to more effectively design and deploy networks, provision services, diagnose network and application performance problems, and predict the impact of network changes. For more information about OPNET and its products, visit www.opnet.com.

About CableLabs

CableLabs is a research and development consortium of cable television system operators representing the continents of North America and South America. CableLabs plans and funds research and development projects that will help cable companies take advantage of future opportunities and meet future challenges in the cable television industry. The Bandwidth Modeling and Management Vendor Forum is a venue where CableLabs members can discuss upcoming bandwidth modeling and management requirements with vendors. This forum also will provide a place where vendors can meet with members to discuss bandwidth management practices and new system capabilities.
It also transfers relevant technologies to member companies and to the industry. In addition, CableLabs acts as a clearinghouse to provide information on current and prospective technological developments that are of interest to the cable industry. CableLabs maintains web sites at www.cablelabs.com; www.cablemodem.com; www.cablenet.org; www.opencable.com; and www.packetcable.com.

Safe Harbour Statement
The statements contained in this press release that are not purely historical are forward-looking statements within the meaning the Private Securities Litigation Reform Act of 1995, as amended, including statements regarding OPNET Technologies Inc.'s expectations, beliefs, intentions, or strategies regarding the future. All forward-looking statements included in this document are based upon information available to OPNET Technologies, Inc. as of the date hereof; OPNET Technologies, Inc. assumes no obligation to update any such forward-looking statements. Forward-looking statements involve risks and uncertainties, which could cause actual results to differ materially from those projected. For a discussion of such risks and uncertainties, see the Company's reports filed with the Securities & Exchange Commission, including its 10-Q for the quarter ended December 31, 2000.

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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.
(240) 497-3000
Media@opnet.com
www.opnet.com

OPNET Investor Relations:
Mel Wesley
OPNET Technologies
(240) 497-3000
ir@opnet.com
www.opnet.com