NetScout : Conference Call Presentation

Q3 FY 2021 Conference Call

NETSCOUT SYSTEMS, INC.

January 28, 2021

©2021 NETSCOUT

January 28, 2021

Agenda

• Introduction & Safe Harbor
• • Tony Piazza, Vice President, Corporate Finance
• CEO Perspective
• • Anil Singhal, President and CEO
• COO Update
• • Michael Szabados, Chief Operating Officer
• CFO Financial Review
• • Jean Bua, EVP and CFO

©2021 NETSCOUT	2	January 28, 2021

Safe Harbor

Forward Looking Statements: Forward-looking statements in this communication are made pursuant to the safe harbor provisions of Section 21E of the Securities Exchange Act of 1934 and other federal securities laws. Investors are cautioned that statements in this communication, which are not strictly historical statements, including without limitation, the fiscal year 2021 outlook for NetScout,

statements regarding market and spending trends, NetScout's optimism about 5G and its belief that adoption will increase spending in the service provider vertical, that NetScout is focused on its team, customers, and driving overall margins while preserving liquidity, a strong balance sheet, and financial flexibility, that NetScout's relevant solutions, trusted brand, strong customer relationships, dedicated

team, and a solid financial profile have positioned it well as it continue to weather the current environment, that NetScout is well- positioned, with long-term trends its favor, when it emerges from the pandemic and resulting macro-economic environment, that NetScout's plans to be active in the market with its share repurchase program depending on market conditions, that NetScout plans to repay $100 million of debt during its fourth quarter, statements regarding product offerings and strategy, as well as the anticipated benefits to NetScout and customers from the same, all constitute forward looking statements that involve risks and uncertainties. Actual results could differ materially from the forward-looking statements due to known and unknown risk, uncertainties, assumptions and other factors. Such factors include slowdowns or downturns in economic conditions generally and in the market for advanced network, service assurance and cybersecurity solutions specifically, including the potential impact of the COVID-19 pandemic; the volatile foreign exchange environment; the Company's relationships with strategic partners and resellers; dependence upon broad- based acceptance of the Company's network performance management solutions; the presence of competitors with greater financial resources than we have, and their strategic response to our products; our ability to retain key executives and employees; the Company's ability to realize anticipated savings from any restructuring actions and other expense management programs; lower than expected demand for the Company's products and services; and the timing and magnitude of stock buyback activity based on market conditions, corporate considerations, debt agreements, and regulatory requirements. For a more detailed description of the risk factors associated

with the Company, please refer to the Company's Annual Report on Form 10-K for the fiscal year ended March 31, 2020 and the

Company's subsequent Quarterly Reports on Form 10-Q, all of which are on file with the Securities and Exchange Commission. NetScout assumes no obligation to update any forward-looking information contained in this communication or with respect to the announcements described herein.

©2021 NETSCOUT	3	January 28, 2021

Non-GAAP Financial Metrics

Regulation G Disclosure: This presentation makes reference to the following non-GAAP metrics: non-GAAP total revenue, non-GAAP product revenue, non-GAAP service revenue, non-GAAP income from operations, non-GAAP gross profit, non-GAAP operating margin, non-GAAP net income, and non-GAAP net income per share (diluted). Non-GAAP revenue (total, product and service) eliminates the GAAP effects of acquisitions by adding back revenue related to deferred revenue revaluation, non-GAAP gross profit, non-GAAP income from operations includes the aforementioned revenue adjustments and also removes expenses related to the amortization of acquired intangible assets, share-based compensation, restructuring charges, intangible asset impairment charges, loss on divestiture, costs related to new accounting standard implementation, and certain expenses relating to acquisitions including depreciation costs, compensation for post-combination services and business development and integration costs while adding back transitional service agreement income. Non-GAAP operating margin is calculated based on the non-GAAP financial metrics discussed above. Non-GAAP net income includes the aforementioned items related to non-GAAP income from operations, and also removes changes in contingent consideration, net of related income tax effects. Non-GAAP diluted net income per share also excludes these expenses as well as the related impact of all these adjustments on the provision for income taxes. Investors are encouraged to review the related GAAP financial measures and the reconciliation of these non-GAAP financial measures to their most directly comparable GAAP financial measures included in the attached tables within this press release. Investors are encouraged to review the related GAAP financial measures and the reconciliation of these non-GAAP financial measures to their most directly comparable GAAP financial measures included in the appendix. These non-GAAP measures are not in accordance with GAAP, should not be considered an alternative for measures prepared in accordance with GAAP (revenue, gross profit and operating margin, net income, cash flow from operations and diluted net income per share), 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. NETSCOUT believes these non-GAAP financial measures will enhance the reader's overall understanding of NETSCOUT's current financial performance and NETSCOUT'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. NETSCOUT believes that providing these non-GAAP measures affords investors a view of NETSCOUT's operating results that may be more easily compared to peer companies and also enables investors to consider NETSCOUT's operating results on both a GAAP and non-GAAP basis during and following the integration period of NETSCOUT's acquisitions. Presenting the GAAP measures on their own, without the supplemental non-GAAP disclosures, might not be indicative of NETSCOUT's core operating results. Furthermore, NETSCOUT believes that the presentation of non-GAAP measures when shown in conjunction with the corresponding GAAP measures provides useful information to management and investors regarding present and future business trends relating to its financial condition and results of operations. NETSCOUT 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. The reconciliation of these non-GAAP metrics to the comparable GAAP metrics are set forth in the accompanying tables in the appendix of this presentation and are available on our website at http://ir.netscout.com.

©2021 NETSCOUT	4	January 28, 2021