Spirent Communications IPv6 Test Systems and Services Validate the U.S. Department of Defense's Key Requirements for IPv6 Transition.

Business Editors

ROCKVILLE, Md.--(BUSINESS WIRE)--April 30, 2004

Spirent Assesses the Security And Mobility Requirements Key To

IPv6 Migration Effort

Spirent Communications (NYSE:SPM) (LSE:SPT) today announced that the U.S. Department of Defense (DOD) is using its full range of IPv6 test solutions including real network traffic emulation for network and device security as well as Mobile IP in an IPv6 environment. The DOD is using Spirent test solutions in its DICE 2004 (Defense Interoperability Communications Exercise) data and Moonv6 phase II test initiatives to validate requirements for its migration to native IPv6 networks and systems.

"Spirent's comprehensive set of IPv6 conformance and performance test suites for routing and application testing played a major role in our DICE 2004 data and Moonv6 phase II test initiatives," said Major Roswell Dixon, United States Marine Corps and tactical networks test officer for the Joint Interoperability Testing Command (JITC). "In particular, Spirent's ability to generate real network traffic and measure IPv6 network's actual performance based on throughput and latency were instrumental to our recent test initiatives. The Spirent equipment enabled the Joint Interoperability Test Command to assess two key IPv6 capabilities, security and mobility."

The JITC is assessing IPv6 for the DOD. IPv6 can support most applications previously used with IPv4, providing those applications have been properly modified, for interaction with IPv6. IPv6 testing is necessary to help evaluate a variety of key interoperability and portability issues associated with the transition to IPv6 and to begin development of methodologies needed to support the coexistence of IPv4 and IPv6.

In the next phases of testing, JITC will be using Spirent's SmartBits(TM) Test Platform and its Avalanche(TM) and Reflector(TM) product lines to test network behavior with IPv4 and IPv6 traffic running simultaneously.

"From the start of the project, our expertise in authoring test methodologies, our in-depth test capabilities in all key technologies involved in IPv6 and our dedicated support and presence in each key location have clearly set us apart from other test vendors," said Barry Phelps, president of Spirent's Performance Analysis-Broadband Division. "We are grateful for the recognition of the major role we have played in these projects thus far and look forward to working hand-in-hand with Major Dixon's team and all the partners to accelerate the completion of the transition over the next several years."

Over the course of the DICE 2003 and 2004 efforts, Spirent has supplied more than 500-man hours of onsite professional services at five locations on the DoD's national test bed, Defense Information Systems Agency (DISA). Those sites include Indian Head, Md. (JITC-E), Ft. Huachuca, Ariz. (JITC-W), Quantico, Va., Scott Air Force Base, St. Louis, Mo., as well as the University of New Hampshire InterOperability Lab (UNH-IOL) where more than $1 million of Spirent products are used in its industry forum test beds.

"For several years, Spirent has been contributing strong, leading-edge test support in many of the most important technologies we test, including the ongoing DoD-backed Moonv6 IPv6 project," said Ben Schultz, managing engineer of the UNH-IOL IPv6 Consortium. "High-caliber test equipment vendors help us to provide a wide array of strong protocol, conformance and interoperability testing to the industry."

Spirent has recently installed a node that links back to the JITC test network at its Performance Analysis headquarters in Calabasas, Calif.

For more information on Moonv6: www.moonv6.com. For more information on Spirent's IPv6 solutions: www.spirentcom.com/ipv6.

About Spirent Communications

Spirent Communications (www.spirentcom.com) is a global provider of integrated performance analysis and service assurance systems that enable the development and deployment of next-generation networking technology such as Internet telephony, broadband services, 3G wireless, global navigation satellite systems, and network security equipment. Spirent's solutions are used by more than 1,500 customers in 30 countries, including the world's largest equipment manufacturers, service providers, enterprises and governments. Based in Rockville, Maryland, Spirent Communications reported 2003 revenue of $394 million and has 1,800 employees worldwide. The company is the largest business group of Spirent plc, traded on the London and New York Stock Exchanges (LSE: SPT; NYSE: SPM; CUSIP number: 84856M209). www.spirent.com. Spirent Communications' sales to the United States government are made through Spirent Federal Systems. www.spirentfederal.com

Spirent, Spirent Communications and the Spirent logo are trademarks of Spirent plc. All other trademarks or registered trademarks are held by their respective companies. All rights reserved.

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