In its lawsuit, filed in the US District Court for the Eastern District of Texas, Cisco alleges that Huawei and two US subsidiaries copied portions of Cisco's Internetwork Operating System (IOS) source code, and used it in the operating system for Huawei's Quidway routers and switches.
The Chinese giant's operating system, Cisco claims, contains a number of text strings, file names and even bugs that are identical to those found in Cisco's IOS source code.
Cisco also alleges that Huawei copied Cisco's Command Line Interface (CLI), which enables users to communicate with the routers, and also screen displays and copyrighted user manuals.
Finally, it accuses Huawei of infringing at least five Cisco patents related to proprietary routing protocols, and of including these technologies in its products.
Huawei, which has a wide customer basis in Asia, is a recent entrant in the US market, where it challenges Cisco's prices. Cisco, however, claims that the purpose of its lawsuit is not to prevent competition.
The company said in a statement: "Innovation and competition are the lifeblood of our industry and must be preserved. But copying is not innovation and the misappropriation of intellectual property is not competition."
Huawei has declined to comment on the lawsuit.
Cisco's filing is available as a 77-page PDF at:
newsroom.cisco.com/dlls/filing.pdf