Acme Packet (APKT) 8-K Acme Packet Reports Results for Fourth Quarter of 2011

Exhibit 99.1

Investor Relations Contact: Brian Norris Acme Packet +1.781.328.4790 bnorris@acmepacket.com Media and Analyst Contact: Mike O’Malley Acme Packet +1.781.869.2975 momalley@acmepacket.com

Acme Packet Reports Results for Fourth Quarter of 2011

– Fourth Quarter Revenues of $83.0 million, up 18% Year-Over-Year –

– Revenues of $307.3 million in 2011, up 33% over 2010 –

Bedford, Massachusetts – February 2, 2012 – Acme Packet, Inc. (NASDAQ: APKT), the leader in session delivery network solutions, today announced results for the fourth quarter and full year ended December 31, 2011. All earnings per share results are on a fully diluted basis.

Results for the Fourth Quarter of 2011

Total revenue for the fourth quarter of 2011 was $83.0 million, an increase of 18% compared to $70.2 million in the fourth quarter of 2010 and an increase of 18% compared to $70.6 million in the third quarter of 2011. Net income for the fourth quarter of 2011 was $8.7 million, or $0.12 per share, compared to $14.5 million, or $0.21 per share, in the fourth quarter of 2010 and $7.9 million, or $0.11 per share, in the third quarter of 2011. Net income on a non-GAAP¹basis for the fourth quarter of 2011 was $18.3 million, or $0.26 per share, compared to $18.1 million, or $0.26 per share, in the fourth quarter of 2010, and $14.6 million, or $0.21 per share, in the third quarter of 2011.

Results for 2011

Total revenue in 2011 was $307.3 million, an increase of 33% compared to $231.2 million in 2010. Net income in 2011 was $44.4 million, or $0.63 per share, compared to $43.0 million, or $0.63 per share, in 2010. Net income on a non-GAAP¹ basis in 2011 was $72.3 million, or $1.02 per share, compared to $55.0 million, or $0.81 per share, in the same period last year.

Company to Host Live Conference Call and Webcast

The Company’s management team plans to host a live conference call and webcast at 4:30 p.m. eastern time today to discuss the financial results as well as management’s outlook for the business. The conference call may be accessed in the United States by dialing 1.800.230.1059 and using access code “APKT”. The conference call may be accessed outside of the United States by dialing +1.612.234.9959 and using access code “APKT”. The conference call will be simultaneously webcast on the Company’s investor relations website, which can be accessed at www.ir.acmepacket.com. A replay of the conference call will be available approximately two hours after the call by dialing 1.800.475.6701 or +1.320.365.3844 and using access code 234067 or by accessing the webcast replay on the Company’s investor relations website.

¹ A reconciliation of GAAP to non-GAAP results, and a statement on the use of non-GAAP financial measures, is included at the end of this press release.

About Acme Packet

Acme Packet (NASDAQ: APKT), the leader in session delivery network solutions, enables the trusted, first-class delivery of next-generation voice, data and unified communications services and applications across IP networks. Our Net-Net product family fulfills demanding security, service assurance and regulatory requirements in service provider, enterprise and contact center networks. Based in Bedford, Massachusetts, Acme Packet designs and manufactures its products in the USA, selling them through over 220 reseller partners worldwide. More than 1,600 customers in 107 countries have deployed over 16,000 Acme Packet systems, including 88 of the top 100 service providers and 41 of the Fortune 100. For more information visit www.acmepacket.com.

Acme Packet, Inc. Safe Harbor Statement

Statements contained herein that are not historical fact 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 to, among other things, expected financial and operating results, expected growth rates, future stock-based compensation and amortization expenses, future business prospects and market conditions. Such forward-looking statements do not constitute guarantees of future performance and are subject to a variety of risks and uncertainties that could cause actual results to differ materially from those anticipated. These include, but are not limited to: the amount of stock-based compensation awarded; the applicable Company stock price used to determine stock-based compensation; the exercise pattern of employee stock options; difficulties expanding the Company’s customer base; difficulties leveraging market opportunities; difficulties providing solutions that meet the needs of customers; poor product sales; long sales cycles; difficulties developing new products; difficulties in relationships with vendors and partners; higher risks in international operations; difficulties managing rapid growth; difficulties managing the Company’s financial performance; the ability to hire and retain employees and appropriately staff operations; the Company’s cash needs; the impact of new accounting pronouncements 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 the Company’s recent filings with the Securities and Exchange Commission, including those factors discussed under the caption “Risk Factors” in such filings.

Acme Packet, Inc.

Condensed Consolidated Statements of Income

(in thousands, except share and per share data)

(unaudited)

	Three Months Ended December 31,					Twelve Months Ended December 31,
	2011			2010		2011			2010
Revenue:
Product	$	64,276		$	57,346	$	241,783		$	186,798
Maintenance, support and service		18,720			12,886		65,534			44,434
Total revenue		82,996			70,232		307,317			231,232
Cost of revenue:
Product		12,155			8,980		42,245			31,866
Maintenance, support and service		3,118			2,301		11,691			9,265
Total cost of revenue		15,273			11,281		53,936			41,131
Gross profit		67,723			58,951		253,381			190,101
Operating expenses:
Sales and marketing		29,940			23,005		105,580			73,067
Research and development		14,221			9,330		51,483			35,565
General and administrative		6,073			4,286		21,844			15,071
Merger and integration-related costs		—			223		300			223
Total operating expenses		50,234			36,844		179,207			123,926
Income from operations		17,489			22,107		74,174			66,175
Other (expense) income, net		(91	)		27		(238	)		381
Income before provision for income taxes		17,398			22,134		73,936			66,556
Provision for income taxes		8,681			7,624		29,576			23,519
Net income	$	8,717		$	14,510	$	44,360		$	43,037
Net income per share:
Basic	$	0.13		$	0.23	$	0.67		$	0.69
Diluted	$	0.12		$	0.21	$	0.63		$	0.63
Weighted average number of common shares used in the calculation of net income per share:
Basic		67,314,606			63,867,523		66,346,008			62,002,543
Diluted		70,679,690			69,418,243		70,902,293			67,915,525

Acme Packet, Inc.

Condensed Consolidated Balance Sheets

(in thousands)

(unaudited)

	December 31, 2011			December 31, 2010
Assets
Current assets:
Cash and cash equivalents	$	160,403		$	91,669
Short-term investments		191,672			179,024
Accounts receivable, net		59,739			34,797
Inventory		10,246			6,662
Deferred product costs		1,515			3,572
Deferred tax asset		4,809			3,814
Income taxes receivable		4,341			9,979
Other current assets		4,385			3,231
Total current assets		437,110			332,748
Long-term investments		20,096			5,030
Property and equipment, net		26,252			17,156
Acquired intangible assets, net		8,569			9,468
Goodwill		3,778			—
Deferred tax asset, net		18,371			14,802
Other assets		230			940
Total assets	$	514,406		$	380,144
Liabilities and Stockholders’ Equity
Current liabilities:
Accounts payable	$	10,318		$	7,161
Accrued expenses and other current liabilities		12,715			14,629
Deferred revenue		22,261			31,998
Total current liabilities		45,294			53,788
Deferred revenue		2,049			1,546
Deferred rent		4,533			4,265
Stockholders’ equity:
Common stock		74			71
Additional paid-in capital		363,769			266,114
Treasury stock, at cost		(37,522	)		(37,522	)
Accumulated other comprehensive income		1			34
Retained earnings		136,208			91,848
Total stockholders’ equity		462,530			320,545
Total liabilities and stockholders’ equity	$	514,406		$	380,144

Condensed Consolidated Statements of Cash Flow

(in thousands)

(unaudited)

	Three Months Ended December 31,						Twelve Months Ended December 31,
	2011			2010			2011			2010
Cash provided by operating activities	$	18,695		$	22,370		$	55,341		$	55,119
Cash used in investing activities		(34,550	)		(60,995	)		(49,036	)		(114,767	)
Cash provided by financing activities		19,296			19,652			62,429			60,846

Acme Packet, Inc.

Statement on Use of Non-GAAP Financial Measures and

Reconciliation of Non-GAAP Net Income and Non-GAAP Net Income Per Share

(in thousands, except share and per share data)

(unaudited)

Statement on Use of Non-GAAP Financial Measures:

To supplement its condensed consolidated financial statements presented in accordance with accounting principles generally accepted in the United States (“GAAP”), the Company discloses certain non-GAAP financial measures, including “non-GAAP net income”, “net income on a non-GAAP basis”, “non-GAAP net income per share”, “non-GAAP EPS”, “net income per share on a non-GAAP basis” and “non-GAAP EPS growth rate”. These non-GAAP financial measures are not presented in accordance with GAAP and are not meant to be a substitute for the most directly comparable GAAP measures of “net income”, “EPS”, “GAAP EPS growth rate” or “net income per share”. Rather, these non-GAAP financial measures should be evaluated in conjunction with its most directly comparable GAAP financial measure and the Company’s financial statements as a whole.

Management uses these supplemental non-GAAP financial measures to evaluate performance period over period, to analyze the underlying trends in the Company’s business, to assess its performance relative to its competitors, and to establish operational goals and forecasts that are used in allocating resources. Management uses these non-GAAP financial measures because they exclude stock-based compensation expense which is a non-cash charge and related payroll taxes, amortization of acquired intangible assets and merger and integration-related costs associated with the Company’s acquisition activities all of which are non-operational costs and expenses. By excluding stock-based compensation expense and related payroll taxes, amortization of acquired intangible assets, and merger and integration-related costs, management can compare the Company’s operations to prior periods and to the operations of other companies in its industry who may have materially different unusual, non-operational charges. Management does not consider any of stock-based compensation expense and related payroll taxes, amortization of acquired intangible assets, and merger and integration-related costs to be part of the Company’s operating activities or meaningful in evaluating the Company’s past financial performance or future prospects. Management believes that excluding these items is useful to investors because it is more representative of ongoing costs and therefore more comparable to historical operations.

Because management uses them, management believes that the disclosure of these non-GAAP financial measures to investors provides greater transparency and useful information to help the investor better understand the Company’s operating performance and to evaluate the methodology used by management to evaluate and measure such performance. Notwithstanding their utility to investors in understanding operational trends, these non-GAAP measures should not be considered measures of the Company’s liquidity. In addition, the Company cautions that its definition of “non-GAAP net income”, “non-GAAP EPS” and “non-GAAP net income per share” may differ from similar measures used by other companies and may differ from period to period. Also, in future periods, management may make other adjustments for expenses and gains that it does not consider reflective of core operating performance in a particular period thereby modifying its definition of “non-GAAP net income”, “non-GAAP EPS” and “non-GAAP net income per share” by excluding these other or additional expenses and gains.

Reconciliation of GAAP to Non-GAAP Financial Measures for the Three and Twelve Months Ended December 31, 2011 and December 31, 2010 and the Three Months Ended September 30, 2011:

Acme Packet, Inc.

Reconciliation of GAAP to Non-GAAP Financial Measures

Three Months Ended December 31, 2011

(in thousands, except per share data)

(unaudited)

	GAAP		Stock-based compensation expense and related payroll taxes			Amortization of acquired intangible assets			Non-GAAP1
Cost of revenue:
Product	$	12,155	$	(314	)	$	(385	)	$	11,456
Maintenance, support and service		3,118		(577	)		—			2,541
Operating expenses:
Sales and marketing		29,940		(4,857	)		(100	)		24,983
Research and development		14,221		(3,063	)		(11	)		11,147
General and administrative		6,073		(1,574	)		—			4,499
Provision for income taxes		8,681		1,148			174			10,003
Net income	$	8,717	$	9,237		$	322		$	18,276
Net income per share:
Basic	$	0.13	$	0.14		$	0.00		$	0.27
Diluted	$	0.12	$	0.13		$	0.00		$	0.26

Acme Packet, Inc.

Reconciliation of GAAP to Non-GAAP Financial Measures

Twelve Months Ended December 31, 2011

(in thousands, except per share data)

(unaudited)

	GAAP		Stock-based compensation expense and related payroll taxes			Amortization of acquired intangible assets			Merger and integration- related costs			Non-GAAP1
Cost of revenue:
Product	$	42,245	$	(1,230	)	$	(1,677	)	$	—		$	39,338
Maintenance, support and service		11,691		(2,095	)		—			—			9,596
Operating expenses:
Sales and marketing		105,580		(17,661	)		(387	)		—			87,532
Research and development		51,483		(10,886	)		(45	)		—			40,552
General and administrative		21,844		(5,472	)		—			—			16,372
Merger and integration-related costs		300		—			—			(300	)		—
Provision for income taxes		29,576		11,022			755			43			41,396
Net income	$	44,360	$	26,322		$	1,354		$	257		$	72,293
Net income per share:
Basic	$	0.67	$	0.40		$	0.02		$	0.00		$	1.09
Diluted	$	0.63	$	0.37		$	0.02		$	0.00		$	1.02

Acme Packet, Inc.

Reconciliation of GAAP to Non-GAAP Financial Measures

Three Months Ended December 31, 2010

(in thousands, except per share data)

(unaudited)

	GAAP		Stock-based compensation expense and related payroll taxes			Amortization of acquired intangible assets			Merger and integration- related  costs			Non-GAAP1
Cost of revenue:
Product	$	8,980	$	(228	)	$	(399	)	$	—		$	8,353
Maintenance, support and service		2,301		(354	)		—			—			1,947
Operating expenses:
Sales and marketing		23,005		(2,156	)		(45	)		—			20,804
Research and development		9,330		(1,369	)		(11	)		—			7,950
General and administrative		4,286		(726	)		—			—			3,560
Merger and integration-related costs		223		—			—			(223	)		—
Provision for income taxes		7,624		1,735			163			—			9,522
Net income	$	14,510	$	3,098		$	292		$	223		$	18,123
Net income per share:
Basic	$	0.23	$	0.05		$	0.00		$	0.00		$	0.28
Diluted	$	0.21	$	0.04		$	0.00		$	0.00		$	0.26

Acme Packet, Inc.

Reconciliation of GAAP to Non-GAAP Financial Measures

Twelve Months Ended December 31, 2010

(in thousands, except per share data)

(unaudited)

	GAAP		Stock-based compensation expense and related payroll taxes			Amortization of acquired intangible assets			Merger and integration- related  costs			Non-GAAP1
Cost of revenue:
Product	$	31,866	$	(805	)	$	(1,536	)	$	—		$	29,525
Maintenance, support and service		9,265		(1,117	)		—			—			8,148
Operating expenses:
Sales and marketing		73,067		(7,635	)		(180	)		—			65,252
Research and development		35,565		(5,112	)		(44	)		—			30,409
General and administrative		15,071		(2,541	)		—			—			12,530
Merger and integration-related costs		223		—			—			(223	)		—
Provision for income taxes		23,519		6,605			630			—			30,754
Net income	$	43,037	$	10,605		$	1,130		$	223		$	54,995
Net income per share:
Basic	$	0.69	$	0.17		$	0.02		$	0.00		$	0.89
Diluted	$	0.63	$	0.16		$	0.02		$	0.00		$	0.81

Acme Packet, Inc.

Reconciliation of GAAP to Non-GAAP Financial Measures

Three Months Ended September 30, 2011

(in thousands, except per share data)

(unaudited)

	GAAP		Stock-based compensation expense and related payroll taxes			Amortization of acquired intangible assets			Merger and integration- related  costs			Non-GAAP1
Cost of revenue:
Product	$	8,778	$	(327	)	$	(385	)	$	—		$	8,066
Maintenance, support and service		3,042		(568	)		—			—			2,474
Operating expenses:
Sales and marketing		27,201		(4,784	)		(101	)		—			22,316
Research and development		13,249		(2,929	)		(11	)		—			10,309
General and administrative		5,406		(1,615	)		—			—			3,791
Merger and integration-related costs		120		—			—			(120	)		—
Provision for income taxes		4,846		3,896			179			43			8,964
Net income	$	7,926	$	6,327		$	318		$	77		$	14,648
Net income per share:
Basic	$	0.12	$	0.09		$	0.01		$	0.00		$	0.22
Diluted	$	0.11	$	0.09		$	0.01		$	0.00		$	0.21

Acme Packet, Inc.

Other Operational Data

(unaudited)

	Three Months Ended						Twelve Months Ended
	December 31, 2011		September 30, 2011		December 31, 2010		December 31, 2011		December 31, 2010
Other operational data:
Depreciation and amortization (in thousands)	$	2,944	$	2,835	$	2,177	$	10,031	$	8,003
Capital expenditures (in thousands)		4,186		5,570		2,770		16,998		13,316
Days sales outstanding		65		65		45		—		—
Total headcount		752		741		570		—		—
Quarterly inventory turnover – annualized		4.41		3.27		5.55		—		—