Hostilities between the companies date from 2002, when Ciena acquired optics equipment maker ONI Systems Corp. Nortel Networks had sued that company in March 2000, alleging patent infringement and misappropriation of trade secrets.
That case settled in January 2003, with Nortel Networks granting Ciena a license to certain patents, and Ciena making a one-time payment of $25 million to its rival.
As part of the settlement, Nortel Networks agreed to dismiss without prejudice another patent infringement claim against Ciena in November 2002. Both companies also agreed not to sue each other for patent infringement for two years, during which time they would seek to negotiate a cross-licensing arrangement.
The two-year period is now up and it seems that negotiations have failed. Ciena filed its lawsuit in the US District Court for the Eastern District of Texas yesterday.
Ciena alleges that Nortel Networks has infringed six patents relating to communications networking technology. It wants a jury trial, an injunction and unspecified damages.
Nortel Networks Corporation has not commented.