Cisco, in a statement on its Web site, said it got the in 2000 after it bought Infogear, which had owned the trademark and had sold iPhone products for several years. According to Cisco, Infogear's original filing for the trademark was on March 20, 1996.
Linksys, a division of Cisco, has been shipping iPhone products since early 2006 and last month expanded the iPhone line further.
"Cisco entered into negotiations with Apple in good faith after Apple repeatedly asked permission to use Cisco's iPhone name," said Mark Chandler, senior vice president and general counsel for Cisco. "There is no doubt that Apple's new phone is very exciting, but they should not be using our trademark without our permission.
"Today's iPhone is not tomorrow's iPhone," he said. "The potential for convergence of the home phone, cell phone, work phone and PC is limitless, which is why it is so important for us to protect our brand."
With the lawsuit, Cisco is asking the court to prevent Apple from copying its iPhone trademark.
Apple CEO Steve Jobs announced the iPhone yesterday at the company's MacWorld Expo in San Francisco even as lawyers were still working behind the scenes to nail down the legal issues associated with the iPhone name.
The iPhone has proved to be the most talked-about product at this year's MacWorld, and its positive reception sent Apple's stock surging over the past two days. The company's stock closed at $97 Wednesday, up nearly 5 percent for the day.
Apple and Cisco have been in negotiations for about two years over Apple's desire to license the iPhone trademark, said Cisco spokesman John Noh. "Because they have been negotiating with us on licensing the trademark all this time, Apple is acknowledging that we own the name," said Noh.
Jobs made no mention of any dispute over the name during his announcement yesterday. Apple officials could not immediately be reached for comment.
Computerworld's Sharon Machlis and the IDG News Service contributed to this report.