WESTFORD, Mass., March 30, 2004 - NetScout Systems, Inc. (NASDAQ: NTCT), a leading provider of enterprise-wide network performance management solutions, announced today that it is the first independent vendor to deliver performance monitoring and reporting for Virtual SAN (VSAN) technology. VSAN is a SAN partitioning technology available through the Cisco MDS 9000 Family of Multilayer Intelligent directors and fabric storage area networking (SAN) switches. In addition, NetScout expanded its Fibre Channel troubleshooting capabilities with new switch roving support. The new features are enabled by firmware enhancements to NetScout's nGenius® Fibre Channel Probes and software enhancements in nGenius Performance Manager 2.0.1.

Through VSANs, storage administrators can build more scalable and reliable SANs able to support multiple applications in a single physical infrastructure. Using NetScout's new VSAN monitoring capabilities, SAN managers can identify, analyze and trend the traffic being delivered for each VSAN for real-time troubleshooting and long term capacity planning. In addition, they can understand the resource requirements of each VSAN and its contributions to overall interswitch link traffic. NetScout's ability to monitor and report on individual types of SAN activity complete the necessary visibility needed by a SAN manager to proactively optimize the SAN.

"NetScout continues to anticipate the needs of large enterprises by introducing performance management for important new technologies such as VSAN," said Nancy Marrone-Hurley, senior analyst with Enterprise Storage Group. "VSAN technology and diagnostics features as well as switch roving are two of the key features driving customers to choose Cisco solutions. By supporting these features, NetScout is providing a level of visibility into SANs that no other vendor can provide today."

The nGenius 9800 Fibre Channel Probe can be configured to automatically discover and monitor Virtual SANs present on Enhanced Inter-Switch Links (EISL) in Cisco Fibre Channel SAN implementations. All the network performance analysis details provided on Fibre Channel segments are now extended to the VSANs. SAN managers can identify, monitor and report protocol details for the link and its associated VSANs, incorporating Fibre Channel specific details such as:

• Traffic statistics of symptoms that may cause performance degradation including Frame Busy and Rejects, Port Busy and Rejects, Zero Credit Events and Initializations.
• New Fibre Channel traffic views that detail Fibre Channel Protocol (FCP), Extended Link Services (ELS) and Basic Link Services activity.
• Detailed views of Upper Layer protocol session activity including SCSI Initiator to Target/LUN conversations for such exchanges as SCSI reads and writes in FCP or Login traffic for ELS.

The addition of switch roving capabilities in the nGenius Fibre Channel Probes offers a cost-effective way to troubleshoot Fibre Channel segments and switches. Connected to a mirror port on a switch, an nGenius Probe can rove to all ports in the switch, allowing SAN managers to troubleshoot under- or over-utilization on a port, identify bandwidth hogs on a port, or execute a packet capture on a port to perform in-depth decode analysis. This new feature makes switch troubleshooting more efficient and also lowers the TCO for enterprises seeking proactive performance management in their Fibre Channel environments.

"We have introduced VSAN and Inter-VSAN routing features in the Cisco MDS 9000 in order to provide SAN managers with the means to better control and segment their storage traffic," said Bill Erdman, director of marketing in the Storage Technology Group at Cisco Systems. "The Cisco MDS 9000 also offers other innovative features such as switch port roving that help customers accelerate troubleshooting. By supporting these features within their nGenius Solution, NetScout is helping our mutual customers effectively address the growing challenges of deploying and managing large SAN infrastructures."

"Many of our enterprise customers are suspecting that the growth and complexity in their Fibre Channel SANs are contributing to slow downs in application performance for their users," said Michael Szabados, senior vice president of product operations for NetScout Systems. "We are committed to supporting innovative features such as VSAN that are helping the SAN industry mature and embrace the best elements of other networking technologies, so that true enterprise-wide network and application performance management can be achieved in a cost-effective manner."

The nGenius® Solution combines SAN and VSAN performance management capabilities with an enterprise-wide solution that allows more thorough understanding of performance issues, end-through-end.

Pricing and Availability

The new enhancements are available in nGenius Performance Manager 2.0.1 Service Pack 1 and nGenius Probe Firmware CDM 2.1 for nGenius 9800 Fibre Channel Probes at no additional charge. For additional product or ordering information about nGenius solutions, call NetScout Systems at 1-800-657-7666 or visit our Website http://www.netscout.com.

About NetScout Systems, Inc.

NetScout Systems, Inc. (NASDAQ: NTCT) is a market leader and pioneer of integrated network performance management products that unify performance across the enterprise. NetScout's nGenius® Performance Management System is helping more than 3000 leading companies increase their return on infrastructure investments by optimizing the performance of networks and applications according to business priorities. NetScout is headquartered in Westford, Massachusetts and has offices worldwide. Further information is available at http://www.netscout.com.

©2004 NetScout Systems, Inc. All rights reserved. NetScout and the NetScout logo, and nGenius are registered trademarks of NetScout Systems, Inc. CDM and the CDM logo, and MasterCare and the MasterCare logo, are trademarks of NetScout Systems, Inc. Other brands, product names and trademarks are property of their respective owners. NetScout reserves the right, at its sole discretion, to make changes at any time in its technical information and specifications, and service and support programs.