Acme Packet Announces Adjustment to Historical Share Count and Earnings Per Share for FY 2006.

BURLINGTON, Mass. -- Acme Packet, Inc. (NASDAQ: APKT), the leader in session border control solutions, today filed with the Securities and Exchange Commission a Current Report on Form 8-K to disclose that it had determined that an adjustment was required to the calculation of the weighted average number of common shares used in determining the earnings per share amounts for the year ended December 31, 2006 which were previously disclosed in its earnings release issued on February 7, 2007 ("Earnings Release"). These changes in the earnings per share calculations have no effect on net income on both a GAAP and non-GAAP basis for the year ended December 31, 2006 as previously reported in the Earnings Release and did not result in a difference from the net income or net income per share for the fourth quarter of fiscal year 2006 as previously reported in the Earnings Release.

While the total amount of GAAP net income and the total amount of non-GAAP net income1 of $28.9 million and $25.0 million, respectively, as previously reported in the Earnings Release is correct, the calculation of net income per share, on both a basic and diluted basis, for the year ended December 31, 2006 as reported in the Earnings Release was incorrect due to an error in determining the weighted average number of common shares used in those calculations. The portion of the Company's preferred stock outstanding prior to their conversion into common stock upon the closing of the Company's initial public offering was inadvertently excluded from the calculation.

GAAP basic earnings per share for the year ended December 31, 2006, is $0.57 per share, rather than $1.14 per share as previously reported in the Earnings Release, and GAAP diluted earnings per share for the year ended December 31, 2006, is $0.50 per share rather than the $0.89 per share as previously reported in the Earnings Release. Non-GAAP basic earnings per share1 for the year ended December 31, 2006, is $0.49 per share rather than the $0.98 per share as previously reported in the Earnings Release, and non-GAAP diluted earnings per share1 for the year ended December 31, 2006 is $0.43 per share rather than the $0.77 per share as previously reported in the Earnings Release. These changes in the earnings per share calculations have no effect on net income on both a GAAP and non-GAAP basis for the year ended December 31, 2006 as previously reported in the Earnings Release. These changes in the earnings per share calculations did not result in a difference from the net income or net income per share for the three months ended December 31, 2006 as previously reported in the Earnings Release.

The following is a reconciliation of the previously reported weighted average number of common shares used in calculating basic and diluted earnings per share to what will be reported in the Company's 2006 Form 10-K, for the year ended December 31, 2006:

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About Acme Packet, Inc.

Acme Packet, the leader in session border control solutions, enables service providers to deliver trusted, first class interactive communications--voice, video and multimedia sessions--across IP network borders. Our Net-Net family has been selected by over 360 service providers in 75 countries to satisfy critical security, service assurance and regulatory requirements in wireline, cable and wireless networks. Our customers include 23 of the top 25, and 72 of the top 100 service providers in the world. These deployments support multiple applications--from VoIP trunking to hosted enterprise and residential services to fixed-mobile convergence; multiple protocols--SIP, H.323, MGCP/NCS and H.248; and multiple border points--interconnect, access network and data center. For more information, contact us at +1 781.328.4400, or visit www.acmepacket.com.

Acme Packet, Inc. Safe Harbor Statement

Statements contained herein that are not historical fact (including those in the section "Company Affirms Business Outlook for 2007") may be forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Such forward-looking statements may relate, among other things, to: the Company's position in the session border control market; the Company's expected financial and operating results, including expected revenue and net income per share (on both a GAAP and non-GAAP basis) for fiscal year 2007; the amount and impact of stock-based compensation charges; the Company's definition of "non-GAAP net income" and/or "non-GAAP net income per share"; the Company's ability to build and expand deployments; the benefits of the Company's products and services; and the Company's ability to achieve its goals, plans and objectives. Such forward-looking statements do not constitute guarantees of future performance and are subject to a variety of risks and uncertainties that could cause our actual results to differ materially from those anticipated. These include, but are not limited to: difficulties in growing our customer base, difficulties leveraging market opportunities, difficulties providing solutions that meet the needs of customers, poor product sales, long sales cycles, difficulty developing new products, difficulty in relationships with vendors and partners, higher risk in international operations, difficulty managing rapid growth, and increased competition. Additional factors that could cause actual results to differ materially from those projected or suggested in any forward-looking statements are contained in our recent filings with the Securities and Exchange Commission, including those factors discussed under the caption "Risk Factors" in such filings.