McData and Brocade manufacture switches, which direct data flow across SANs - high-speed subnetworks that interconnect different kinds of data storage devices with data servers.
McData filed the suit in the US District Court for Colorado for infringement of its patented traffic filtering technology, which can be used to avoid bottlenecks in the network.
Thomas McGimpsey, vice-president and general counsel at McData, said his company's 25 patents are valuable company assets. "This action is a clear signal to the market that McData will vigorously assert its intellectual property rights against infringements," he said
Brocade said the allegations are "without merit" and that it intends to defend the lawsuit vigorously.
McData, which was spun off from EMC in February last year, manufactures high-end switches that have up to 64 ports and are completely redundant for increased reliability.
A McData spokeswoman said the lawsuit specifically targets Brocade's Silkworm 3800, a 2Gbit/sec., 16-port switch; its highest-end SilkWorm 12000 64/128-port switch; "and any other products that have frame filtering."
The 12000 is Brocade's most recent product and is a direct challenge to McData's high-end offerings.