NetFuel, Inc. v. Cisco Systems Inc.

Background

NetFuel accused 27 families of Cisco routers and switches of infringing U.S. Patent Nos. 7,747,730 and 9,663,659. The patents concern software agents that monitor and manage computer networks. The accused Cisco features were Embedded Event Manager (EEM), Control Plane Policing (CoPP), Local Packet Transport Services (LPTS), and Excessive Punt Flow Trap (EPFT). Cisco’s motion addressed infringement theories involving EEM with CoPP or LPTS; it did not address the EPFT theory.

NetFuel’s theory was that EEM could act as a global modeler and CoPP or LPTS could act as agents receiving policy changes. Cisco argued that its products lacked claim limitations requiring policy changes to be communicated to or applied by CoPP or LPTS.

Legal standard

Summary judgment is a procedure for deciding a claim without a trial when there is no genuine dispute about an important fact and the moving party is entitled to judgment under the law. For patent infringement, the patent owner must provide evidence that the accused product meets every required claim limitation. The court must view the evidence and reasonable inferences in favor of the party opposing summary judgment.

Claims and capability

The court concluded that the computer-readable medium claims should be analyzed like the system claims, based on whether the accused products were capable of performing the claimed functions. The system and computer-readable medium claims therefore did not require proof that the functions were operating in every instance. The method claims, by contrast, required evidence that each claimed step had actually been performed at least once, although circumstantial evidence could be used.

Evidence of infringement

NetFuel presented evidence that users could employ EEM applets to modify CoPP policies. The evidence included:

- A third-party blog post describing how to use EEM to create and apply a service policy to the control plane. NetFuel’s expert, Dr. Aviel Rubin, testified that he followed the instructions, with minor changes, and that EEM dynamically modified CoPP traffic-policing rules. - Cisco Technical Assistance Center documents in which Cisco personnel advised customers to use EEM scripts or applets. Dr. Rubin opined that these materials showed EEM changing policies affecting CoPP or the relevant interfaces. Cisco and its expert, Dr. Kevin Almeroth, disputed those conclusions. - Dr. Rubin’s tests on a Cisco Cloud Services Router 1000V. In the tests, EEM applets removed, applied, or changed the rate of a CoPP traffic-policing policy. Dr. Rubin concluded that EEM could communicate or provide policies to CoPP.

Cisco argued that the use of applets amounted to modifying the accused products, which would prevent a finding of infringement based only on the products’ capability. The court found a factual dispute about whether applets altered the products or merely activated functionality already present in EEM. The court noted evidence that EEM required users to provide applets to operate meaningfully, that applets were configuration tools rather than source code, and that they did not change the source code of EEM or the accused products.

Ruling

The court held that the evidence created triable factual disputes concerning the computer-readable medium claims and system claims. The disputes included whether the accused products were reasonably capable of satisfying the patent limitations and whether applets modified the products or activated existing functionality. The court also found sufficient circumstantial evidence to create triable disputes concerning the method claims, including evidence about customer instructions, third-party applets, and Dr. Rubin’s testing.

The court therefore denied Cisco Systems Inc.’s motion for summary judgment. It did not make a final determination of infringement, and it did not consider NetFuel’s EPFT infringement theory because Cisco’s motion did not address it.