Acme Packet (Nasdaq: APKT) will step up to the earnings plate to take a swing tonight after market close, and investors are expecting it to be a volatile one -- at least, if you ask the options market.

Shares have fallen spectacularly from the high of $84.50 reached just over a year ago, worth just a third of what they were. Part of what's driven the drop are concerns over Acme Packet's ability to deliver big deals at carrier customers AT&T (NYSE: T) and Verizon (NYSE: VZ).

In October, CEO Andy Ory assured investors that a big order with Ma Bell was still being booked, but that it was seeing delays and merely being pushed back into the fourth quarter. Acme Packet even reaffirmed its full-year outlook at the time to back up this belief. A few months later, that full-year outlook was slashed, with the company citing "uncertainty in North American service provider markets," sparking concerns that Big Red was cutting back.

Its official fourth-quarter results received a warm welcome, in that there weren't more disappointing developments to report.

This time around, analysts are forecasting revenue to be $69.3 million, which would represent a 6.3% decline from the year before. Earnings per share are also expected to shrink to $0.17, a dime less than the first quarter of 2011. I'll be looking at what happens to the product portion of revenue, because that will give a clearer hint to Acme Packet's prospects as carriers use its session border controllers to lay the groundwork for the inevitable shift to Voice-over-LTE, or VoLTE.

If Acme Packet can deliver this time around, it will help the company and Ory regain some credibility. Ory's overpromising and underdelivering earned him a Foolish CEO Gaffe of the Week, but the long-term story remains compelling if the company can walk the talk.

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Fool contributor Evan Niu owns shares of Verizon Communications and AT&T, but he holds no other position in any company mentioned. Click here to see his holdings and a short bio. Motley Fool newsletter services have recommended buying shares of Acme Packet. The Motley Fool has a disclosure policy.

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