Spirent Communications and Psytechnics Partner to Offer Video Quality Assessment Solution; First-to-Market Solution Enables Carriers to Roll out High Quality Video with Triple Play Services.

ROCKVILLE, Md. -- Spirent(R) Communications (NYSE:SPM) (LSE:SPT) today announced it is partnering with Psytechnics, the global leader in voice and video quality assessment software, to offer carriers, service providers and equipment vendors the industry's first video quality assessment test system. This Spirent solution responds to the urgent need of determining video quality as well as a broad range of video distortion and degradation parameters under various network configurations and real-world load conditions.

"As Triple Plays gains momentum, the interest of service providers and carriers in testing and monitoring video is rising. If cable companies require the addition of voice to rollout their Triple Play offerings, traditional phone companies will need video," said Jessy Cavazos, program manager of the Communications Test Sector at Frost & Sullivan. "Customers refuse to compromise on voice quality, demanding at least the same level of quality from VoIP that they receive from their traditional phone systems. Similarly, they will demand at least the same level of video quality than the one they receive from cable technology."

High quality video services are a compelling business driver for the successful adoption of triple play services. Carriers and cable providers are in the early phase of planning, validating and demystifying advanced video on-demand and IPTV technologies. Video quality assessment will be a critical component of the successful adoption of these services. Ensuring satisfactory end user experience of these new services is a necessary ingredient of a successful service rollout.

"Assuming a rigorous testing regime of the IP infrastructure is sufficient for the proper delivery of high quality voice and video is a common mistake made by many," said Bahaa Moukadam, vice president - IP Telephony, Spirent Communications. "Though necessary, infrastructure testing must be combined with direct media quality assessment in the lab and on the network. Psytechnics brings significant value to this relationship based upon its vast research and experience in media quality measurement. Spirent reviewed several technologies and we decided Psytechnics was the best choice for full reference video quality assessment."

Spirent has licensed the Psytechnics Video Agent (PVA), a full reference video quality measurement tool based on the ITU J.144 standard and part of the Psytechnics family of Assessment Modules. Spirent has integrated the PVA into its Abacus 5000 IP Telephony Test Migration System.

The test system works by sending reference video clips into the device or system under test. Using a complex video quality assessment algorithm, the test system compares the received video clip from the output of the system under test to the reference clip and provides a MOS (Mean Opinion Score) video quality rating score on a scale of 1 to 5. Additionally, the test system provides several video degradation metrics including Blockiness, Blurriness, Jerkiness, Frame Freeze Events, Frame Skip Events, Temporal Complexity and Spatial Complexity. In addition to performing this testing in a lab environment, two or more test systems can be distributed at various points of the network to perform pre-production assessment of voice and video quality in a real network environment with various levels of real world traffic load. This will help carriers diagnose problems in the network and get an accurate picture of what the network is capable of and where it may break down.

"Spirent is the proven market leader in testing, and together with Psytechnics' expertise in video quality assessment, this partnership brings a very powerful and unique solution to the market," said John Winchester, CEO of Psytechnics. "We are seeing dramatic growth in the roll-out of content-delivery programs over IP such as video on-demand over IP. It's critical to ensure video broadcasts are of high enough quality to win and retain customers. Psytechnics' technology is based on many years of research into voice quality tools and video quality is a natural extension to this experience. We look forward to building a strong relationship with Spirent and quickly rolling the solution out to many high-profile customers."

The first public demonstrations of the solution will take place at separate events in Europe and the United States. First, VON Europe 2005 Conference & Expo, May 23-26 at the Stockholm International Fairs in Stockholm, Sweden booth #771. Second, Supercomm 2005, June 6- 9, McCormick Place, Chicago, booth #77054 for Spirent and booth #75079 for Psytechnics.

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. 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 Psytechnics

Psytechnics is the global leader in voice and video quality assessment solutions, with in excess of 2000 software licenses installed at over 200 carriers worldwide. The software integrates into telecommunications test equipment, network elements, delivery devices (phones and set-top boxes) and forms a part of an integrated Operational Support System (OSS). The company calculates the Mean Opinion Score (MOS), a measure of quality from a human perspective. MOS metrics may be used to test services, manage networks and set SLAs from a meaningful, quality viewpoint.

Psytechnics is headquartered in Ipswich, United Kingdom, with North American offices in Boston. Customers include Agilent Technologies, Ascom, Brix, Empirix, Intel, Malden, Electronics, Micromuse, Minicom, NetTest, Radcom and Tektronix/Inet. The company holds more than 30 patents in the area of voice quality measurement and its products include the ITU standards P.563 P.SEAM, P.562 CCI and P.862 PESQ, psyVoIP for IP networks and NiQA for monitoring the quality of other network traffic.

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