While the networking firm had said only yesterday that it expected an agreement that would allow both firms use the iPhone name for their respective handheld communicators, the company filed a lawsuit after the newly rechristened Apple, Inc. apparently failed to sign the plan before an imposed Tuesday night deadline.
"Cisco entered into negotiations with Apple in good faith after Apple repeatedly asked permission to use Cisco's iPhone name," claimed Cisco senior VP and general counsel Mark Chandler in a statement accompanying the suit.
The networking giant, which released its Linksys iPhone scarcely three weeks before the Macworld San Francisco keynote on January 9th, had obtained the trademark in 2000 but did not believe it had a reason to use the iPhone title until it was ready to ship a VoIP handset that it thought merited the name.
During his keynote presentation at Macworld San Francisco, Apple CEO Steve Jobs said that his company's cellular network-based iPhone had been in development for roughly two and a half years, placing its inception approximately four years after Cisco originally registered the trademark.
Apple has so far remained silent regarding the progress of negotiations and the resulting lawsuit.