Q2 FY 2010                    
                        GAAP            Non-GAAP      
 Revenue                $59.7 million   $60.1 million 
 Net income             $7.1 million    $9.0 million  
 Net Income per share   $0.17           $0.22         


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NetScout Systems, Inc. (NASDAQ: NTCT), an industry leader for advanced network and service assurance solutions, today announced financial results for its second quarter of fiscal year 2010, ended September 30, 2009.

Total GAAP revenue for the second quarter of fiscal year 2010 was $59.7 million, and non-GAAP revenue was $60.1 million. Non-GAAP revenue excludes the purchase accounting adjustment to record the acquired Network General deferred revenue at fair value. Product revenue was $30.6 million on a GAAP and non-GAAP basis. Service revenue was $29.1 million on a GAAP basis and $29.5 million on a non-GAAP basis.

GAAP net income for the quarter was $7.1 million, or net income per diluted share of $0.17. GAAP income from operations was $11.7 million. On a non-GAAP basis, net income was $9.0 million, or $0.22 per diluted share, and non-GAAP income from operations was $14.8 million. Non-GAAP income from operations excludes the purchase accounting adjustment to record the acquired Network General deferred revenue at fair value, as well as share-based compensation expenses and amortization of acquired intangible assets. Non-GAAP net income excludes these effects as well as their related impact on the provision for income taxes. A reconciliation between GAAP and non-GAAP results is included in the attached financial tables.

"Our results are still being affected by the slow economy and depressed IT spending across most of our verticals. However, we are seeing signs of improvement that are appearing in our pipeline, and we continue to expect the economy and IT spending to improve in the second half of our fiscal year, which will amplify our normal seasonality. We are confirming our expectation that our bookings and revenue will accelerate in Q3 and Q4, on the strength of the pipeline," said Anil Singhal, President and CEO of NetScout Systems. "We have maintained focus on cost and expense management, improving to a 25% non-GAAP operating margin despite lower revenue and, as a result, we are raising the low end of our FY 2010 EPS guidance range. We are lowering the high end of our FY 2010 revenue guidance range, recognizing weaker first half revenue. Looking forward, we see increasing opportunity in the wireless service provider market and we are stepping up our investment to accelerate our market share gains there. We are optimistic about our future growth in service provider and our other major market sectors."

Second Quarter Financial Highlights:

GAAP revenue decreased 13% year-over-year and increased 3% sequentially. Non-GAAP revenue decreased 18% year-over-year and increased 2% sequentially.

GAAP product revenue decreased 22% year-over-year and increased 8% sequentially. Non-GAAP product revenue decreased 25% year-over-year and increased 8 % sequentially.

GAAP service revenue decreased 1% year-over-year and 2% sequentially. Non-GAAP service revenue decreased 8% year-over-year and 3% sequentially.

GAAP operating margin was 20% up from 13% a year ago and up 5 points sequentially. Non-GAAP operating margin was 25% up from 22% a year ago and up 4 points sequentially.

As of September 30, 2009, total cash and cash equivalents and short and long-term marketable securities were $142.8 million, up $1.2 million from $141.6 million as of the end of the prior quarter.

Company Highlights:

In the second quarter we released the nGenius® InfiniStream 2900 Series appliance, extending our end-to-end Unified Service Delivery Management strategy by enabling more visibility in more places. This new appliance has been designed and purpose-built for deployment in areas where there are cost constraints and extends the reach of our InfiniStream intelligent Deep Packet Capture technology closer to the user.

We began shipping the newly enhanced version of Sniffer® Global network analyzer that is integrated with Cisco's Wireless Mobility Service Engine to more quickly identify and resolve network and service performance issues over wireless LAN networks.

NetScout was added to Standard & Poor's "S&P SmallCap 600", effective September 23, 2009.

Recently we announced the availability of nGenius Virtual Agent software, extending service delivery visibility into applications contained within a virtual computing environment. As a virtualized implementation of the company's widely deployed nGenius Probe technology, the nGenius Virtual Agent seamlessly extends high-performance packet-flow monitoring and analysis capabilities deeper into the data center and private clouds ” enabling the IT organization to regain end-to-end visibility of application traffic from within virtual servers.

Recently we joined the Cisco Developer Network Program in the program's Unified Communications technology category. In addition, NetScout Systems nGenius Performance Manager version 4.6 and Sniffer Intelligence version 4.6 have successfully completed interoperability testing with Cisco Systems Unified Communications Manager 6.1.

Guidance

NetScout has tightened the guidance range, lowering the high end of revenue guidance and raising the low end of net income per diluted share guidance for fiscal year 2010. GAAP revenue is now expected to be in the range of $259 to $269 million and non-GAAP revenue between $260 million to $270 million. GAAP net income per diluted share is now expected to be in the range of $0.65 to $0.75 and non-GAAP net income per diluted share is expected to be between $0.85 and $0.95. The fiscal year 2010 non-GAAP revenue expectation excludes the purchase accounting adjustment to fair value of approximately $1.3 million of Network General's deferred revenue and the non-GAAP net income per diluted share expectation excludes the deferred revenue purchase accounting adjustment, as well as share-based compensation expenses of approximately $5.6 million, amortization of acquired intangible assets of approximately $5.9 million, and the related impact of these adjustments on the provision for income taxes of $4.9 million.

Use of Non-GAAP Financial Information

To supplement the financial measures presented in the Company's press release in accordance with accounting principles generally accepted in the United States ("GAAP"), the Company also presents non-GAAP measures relating to revenue, income from operations, net income and net income per diluted share which were adjusted from amounts determined based on GAAP to exclude the purchase accounting adjustment representing the fair value of Network General's deferred revenue, share-based compensation expenses, amortization of acquired intangible assets, as well as the related income tax effects.

These non-GAAP measures are not in accordance with GAAP, should not be considered an alternative for measures prepared in accordance with GAAP, and may have limitations in that they do not reflect all of NetScout's results of operations as determined in accordance with GAAP. These non-GAAP measures should only be used to evaluate NetScout's results of operations in conjunction with the corresponding GAAP measures. The presentation of non-GAAP information is not meant to be considered superior to, in isolation from or as a substitute for results prepared in accordance with GAAP.

The Company believes these non-GAAP financial measures will enhance the reader's overall understanding of NetScout's current financial performance and the Company's prospects for the future by providing a higher degree of transparency for certain financial measures and providing a level of disclosure that helps investors understand how the Company plans and measures its own business. The Company believes that providing these non-GAAP measures affords investors a view of the Company's operating results that may be more easily compared to peer companies and also enables investors to consider the Company's operating results on both a GAAP and non-GAAP basis during the period where GAAP results are affected by the Company's acquisition of Network General. Presenting the GAAP measures on their own would not be indicative of the Company's core operating results. Furthermore, NetScout believes that the presentation of non-GAAP measures when shown in conjunction with the corresponding GAAP measures provide useful information to management and investors regarding present and future business trends relating to its financial condition and results of operations.

As discussed above, Company management regularly uses supplemental non-GAAP financial measures internally to understand, manage and evaluate its business and to make operating decisions. These non-GAAP measures are among the primary factors that management uses in planning and forecasting future periods.

CONFERENCE CALL INSTRUCTIONS

The Company invites shareholders to listen to its conference call today at 4:30 p.m. ET, which will be webcast live through the Company's website at http://www.netscout.com/investors. Alternatively, people can listen to the call by dialing866-701-8242 for U.S./Canada and 763-416-6912 for international callers and using conference ID: 35698529. A replay of the call will be available after 7:30 p.m. ET on October 22 for approximately one week. The number for the replay is 800-642-1687 for U.S./Canada and 706-645-9291 for international callers. The conference ID is: 35698529.

About NetScout Systems

NetScout Systems, Inc. is the market leader in Unified Service Delivery Management enabling comprehensive end-to-end network and application assurance. For 25 years, NetScout has delivered breakthrough packet-flow technology that provides trusted and comprehensive real-time network and application performance intelligence enabling unified assurance of the network, applications and users. These solutions enable IT staff to predict, preempt and resolve network and service delivery problems while facilitating the optimization and capacity planning of the network infrastructure.