Internet telephony company Vonage Holdings Corp. (Nasdaq: VG) issued a statement on Monday declaring its confidence that it will prevail in its appeal against an injunction issued last week.

Shares of the firm shot up in afternoon trading, rising 15.3 percent, or 46 cents to hit $3.46 on the Nasdaq Stock Market.

On Friday a U.S District judge said Vonage violated the intellectual property of its rival, Verizon (NYSE: VZ), issuing an injunction against patented Verizon technologies, sending shares tumbling more than 20 percent.

In a statement today, Vonage CEO Mike Snyder said that the injunction ruling of last week was only a small part of a long trial, and the market reaction was unfounded.

The fact is we’ve been preparing for this verdict and the possibility of an injunction for months, Snyder said. For the market to react the way it did to the recent rulings shows an unfortunate lack of understanding of the judicial/appellate system, a lack of appreciation of Vonage’s resourcefulness, or, perhaps, both.

The technology in question deals with the way Internet calls are routed to landline phones.

Sharon O’Leary, the company’s chief legal officer said in a statement that she believes the verdict will be over-turned based on the faulty claim construction of the patents involved.”

Verizon shares fell 1.68 percent, or 64 cents to $37.48 on the New York Stock Exchange.