In a courtroom, that may not be the best attitude to have, he said. "There's a good chance the judge will have a Cisco-based phone sitting on his desk. It's one of those cases where it could get ugly fast."

The Cisco lawsuit alleges that Apple infringed on its iPhone trademark and that with its Tuesday announcement Apple is unfairly competing with Cisco. The lawsuit is seeking a jury trial and unspecified monetary damages.

Cisco spokesman John Noh said Thursday that Cisco believed that Jobs' announcement of the Apple iPhone at Macworld meant that the company agreed to the terms set out in their negotiations and had signed and approved the contracts. "At that time, we were still expecting them to send over an approved agreement," Noh said. Instead, Cisco learned that Apple didn't sign the deal and made the announcement anyway, he said.

Apple spokesman Steve Dowling did not return several phone messages Thursday.