Arbor Networks Continues on Rapid Growth Track; More Than Doubles Sales Revenue; Demonstrates Market Leadership.

LEXINGTON, Mass. -- Arbor Networks, a leader in network security, today announced that it continues on its rapid growth path and has closed 2004 with more than a 130% increase in sales over 2003. Arbor also solidified its market leadership with new and expanded deployments for service providers and enterprises in the U.S. and throughout the world.

"Arbor had a terrific 2004. Not only have we more than doubled sales, but we're also seeing increased global adoption of our internal security product in the enterprise market as well as our continued dominance in the service provider market," said Tom Schuster, newly appointed president of Arbor Networks. "Likewise we've had tremendous recognition from the industry through the awards we've received. We're looking forward to continued growth in 2005 by expanding our security product set to help our enterprise customers better secure their corporate networks."

Arbor's highlights for 2004 include:

--With more than double sales revenues, Arbor Network's Peakflow platform continued to be the top pick among service providers and enterprises. Arbor now has more than 100 customers and has expanded existing deployments including: Abilene Network, British Telecom, CableLabs, Cox Communications, Dacom, EarthLink, Energis, Harvard University, Internet2, ITC^DeltaCom, University of Pennsylvania, TM Net and many more.

--Major industry accolades including Red Herring's Top Private Companies, the MITX award for "Best Network Infrastructure Application," Secure Enterprise's Tester's Choice award and InfoWorld's Test Review "Excellent" rating.

--The introduction of Peakflow X 3.0 - the ground-breaking internal network security system with real-time situational awareness to stop worms and harden internal infrastructure. Peakflow X also received OPSEC(TM) (Open Platform for Security) certification from Check Point Software.

--The introduction of Peakflow SP Managed Services, the first solution that enables service providers to offer distributed denial of service (DDoS) protection to their enterprise customers.

--Arbor's security and networking experts continued to educate the market. Danny McPherson, director of business development at Arbor, co-authored the book, Practical BGP and Arbor experts were invited to share their knowledge about DDoS, worms and internal security at events and symposia worldwide, including: the RSA Conference, NANOG, Networld+Interop, NetSec, Cisco Networkers, Black Hat, the Silicon Valley Bank Tech Forum, CSI Annual Conference, CanSecWest, and APRICOT.

About Arbor Networks

Arbor Networks protects the world's largest networks from known and unknown Internet attacks and operational vulnerabilities. Arbor Networks' Peakflow platform is the most broadly deployed network integrity platform in the world, with more than 100 customers that include leading service providers, MSOs in North America, Europe and Asia Pacific, the U.S. Department of Defense, and Fortune 500 companies. Arbor's systems protect organizations from zero-day security threats such as DDoS attacks and worms, and operational vulnerabilities such as inefficient peering and routing instability. Arbor is headquartered in Lexington, MA, with a research and development office in Ann Arbor, MI and international headquarters in London and Beijing.

Note to Editors: Arbor Networks and Peakflow are registered trademarks and the Arbor Networks logo and ArbOS are trademarks of Arbor Networks, Inc. in the USA and other countries. All other trademarks are the property of their respective owners.