Will McData suit stop Brocade shipments?

McData and Brocade make networking hardware that connects storage systems and servers in storage area networks, or SANs. McData sued in February, arguing that Brocade's products infringe on a patent McData holds on "frame filtering," in which a switch monitors and measures data flow in itself to obtain higher efficiency.

Brocade said the suit was " without merit" at the time, and on Tuesday it reiterated its position with the request for preliminary injunction that McData filed Monday.

"The patent-infringement lawsuit is without merit and...Brocade intends to fight this vigorously in the courts," the company said in a statement Tuesday.

Brocade added that it has "a contract with McData that includes a (patent) cross-license and agreement not to sue covering Brocade's products." And Brocade said McData's patent is invalid because "it relates to technology developed by Brocade and others prior to McData's filing of the patent."

McData said it's "extremely concerned" that Brocade began shipping its new Silkworm 3200 switch last week, a product that uses frame filtering.

Brocade has leading market share for SAN switches, but McData is stronger in the high end of the market, analysts say.

McData sued in Denver Federal District Court.