FOR IMMEDIATE RELEASE

SPIRENT COMMUNICATION® LAUNCHES PROOF OF CONCEPT LAB TO ACCELERATE DEVELOPMENT OF 10 GIGABIT ETHERNET DEVICES

Convenient location supports vendors in cost effective development of higher-density switches and routers

ROCKVILLE, Md. – February 20, 2006 — Spirent Communications (NYSE: SPM; LSE: SPT) today announced the launch of the Spirent Proof of Concept lab to assist network equipment manufacturers in the design and development of 10GigE switches and routers. Spirent Communications is a global provider of integrated performance analysis and service assurance systems that enable the development and deployment of next-generation networks and services.

“Proof of Concept testing is a critical step in the design and development process, helping to get the design job done right the first time,” said Michael Howard, principal analyst, Infonetics Research “No vendor can afford to let customers detect problems after the switches and routers are deployed on an enterprise backbone. Neither can manufacturers afford unnecessary delays in going to market.”

Using the industry proven Spirent TestCenter system, development teams can cost effectively validate product design viability prior to large scale investment in system development, manufacturing and testing. Pre-testing and design verification allows network equipment manufacturers to rapidly bring to market high density 10GigE devices. The lab, located in Spirent’s Sunnyvale, Calif. office, is the world’s largest Proof of Concept test bed for 10GigE equipment.

“Leading vendors are developing higher density 10GigE devices this year and will face challenges integrating all the Layer 2/3, security and routing features at 10GigE rates,” said Neal Roche, director of Product Marketing for Spirent Communications. “The Proof of Concept lab enables them to conduct pre-deployment testing without incurring a large upfront capital investment or delaying their market launch.”

The lab features 64 ports of 10GigE with the latest Spirent TestCenter software. Spirent TestCenter offers the most complete coverage of test cases for switches/routers. The company also announced a new 2-port 10GigE Multi-MSA Test Module for the Spirent TestCenter system. This will allow users to scale to more than 100 test ports in a single rack, providing the world‘s highest 10GigE port density test bed.

The lab offers integrated testing of scalability, quality of service and layer 2/3 security, which provides more realistic results compared with serial testing. The test methodology is built into the software so users do not have to waste time designing custom scripts from the ground up. The Proof of Concept lab provides the most realistic environment by utilizing full line rate 10GigE Network Emulators from Anue Systems. Spirent has partnered with Anue Systems to offer customers the ability to precisely emulate delays and impairments found on a wide variety of live networks.

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 2004 revenue of $460 million and has 1,700 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.

About Anue Systems, Inc.

Anue Systems (http://www.anuesystems.com) is the recognized world leader in Network Emulation testing for 10 GigE as well as other Ethernet speeds down to 10 Mb/s, SONET/SDH and Fibre Channel. Anue has unmatched ease of use, features, and protocol support. Anue’s Network Emulators offer the unique combination of hardware-based architecture for true full-line rate processing, layer 1 and 2 emulation, multi-protocol support up to 11 Gbps, and dynamically changing impairment profiles, which offer preemptive and proactive validation of Interoperability and Proof of Concept, Distributed Applications, Satellite Communications, Disaster Recovery and Business Continuity Plans, Video and Voice applications, Network Quality of Service, Next Generation SONET/SDH, and SAN extension. Based in Austin, TX, Anue Systems has built a world-class team with expertise in network testing. For more information, visit Anue’s website at http://www.anuesystems.com.

Contacts:

Parag Sheth
Spirent Communications
(301) 648-0289
parag.sheth@spirentcom.com

Kevin Przybocki
Anue Systems
(512) 527-0453
kap@anuesystems.com

Sailaja Tennati
Calysto Communications
(404) 266-2060 Ext. 25
stennati@calysto.com

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

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