Frost & Sullivan Names Spirent® Communications Market Leader in Network Security Test

Business Wire, May 14, 2007

Spirent Offers Unmatched Capabilities in Network Security Testing

SUNNYVALE, Calif. -- Spirent Communications plc (NYSE:SPM) (LSE:SPT) a global provider of performance analysis and service management solutions, has received the 2007 Frost & Sullivan Market Leadership Award in recognition of its leadership position in the security test equipment market. According to Frost & Sullivan, Spirent has captured more than 25 percent of the market with innovative solutions that enable network operators, equipment manufacturers and enterprises to seamlessly deploy mission critical technologies in a secure environment.

"Testing for security constraints and ensuring reliability are critical in today's rapidly growing networking industry," said Gabriel Khon, research analyst, Test & Measurement Group at Frost & Sullivan. "Spirent offers the industry's most comprehensive line of products for testing the performance and capacity of security devices."

Spirent was recognized with this award because of its comprehensive suite of security and performance solutions that deliver a proactive approach to network testing. Comprised of Avalanche, ThreatEx and Spirent TestCenter, Spirent's security test solutions are designed to detect potential problems before new devices or software upgrades are deployed. These products, combined with Spirent's strong Professional Services Group, have made Spirent the leader in network security testing.

"Spirent's network security solutions play a critical role in enabling our customers to deploy resilient, reliable networks in the face of evolving security concerns," said Rob Piconi, Chief Operating Officer for Spirent Communications. "Frost & Sullivan's Market Leadership Award validates our commitment to developing and delivering cutting-edge solutions that address the needs of the security market."

Spirent advocates thorough testing of networks and devices to reveal weaknesses and faults prior to deployment or service launch. This streamlines network and service deployments, prevents downtime and ensures optimum performance once the system is online.

Spirent's security testing products are used for testing firewalls, IDS/IPS, IPSec VPN concentrators, SSL accelerators, Network Access Control (NAC) solutions and other security devices in the network. Spirent's ThreatEx exposes devices and networks to actual threats in a controlled lab environment to assess their defensive capabilities. Spirent TestCenter is a next-generation, highly scalable platform, that generates Layer 2 to 7 traffic and can be used to certify any network device or service.

About Frost & Sullivan

Frost & Sullivan, a global growth consulting company, has been partnering with clients to support the development of innovative strategies for more than 40 years. The company's industry expertise integrates growth consulting, growth partnership services, and corporate management training to identify and develop opportunities. Frost & Sullivan serves an extensive clientele that includes Global 1000 companies, emerging companies, and the investment community by providing comprehensive industry coverage that reflects a unique global perspective and combines ongoing analysis of markets, technologies, econometrics, and demographics. For more information, visit www.awards.frost.com.

About Spirent Communications

Spirent Communications (www.spirent.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 Communications' solutions are used by more than 1,700 customers in 30 countries, including the world's largest equipment manufacturers, service providers, enterprises and governments. Based in Sunnyvale, CA, Spirent Communications has 1,900 employees worldwide.

Spirent Communications plc Ordinary shares are traded on the London Stock Exchange (LSE:SPT) and on the New York Stock Exchange (NYSE:SPM) (CUSIP number: 84856M209) in the form of American Depositary Shares ("ADS"), represented by American Depositary Receipts, with one ADS representing four Ordinary shares. Spirent Communications' sales to the United States government are made through Spirent Federal Systems Inc. (www.spirentfederal.com)

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

This press release may contain forward-looking statements that are based on current expectations or beliefs, as well as assumptions about future events. By their nature, forward-looking statements are inherently predictive, speculative, and involve risk and uncertainty because they relate to events and depend on circumstances that will occur in the future. You should not place undue reliance on these forward-looking statements, which are not a guarantee of future performance and are subject to factors that could cause our actual results to differ materially from those expressed or implied by these statements. These risks include the risks described from time to time in Spirent Communications plc's Securities and Exchange Commission periodic reports and filings. The Company undertakes no obligation to update any forward-looking statements contained in this press release, whether as a result of new information, future events or otherwise.