Federal Circuit Highlights Peril of Unresolved Claim Construction in Egenera v. Cisco
The CAFC reminds: don't save it for appeal!
The United States Court of Appeals for the Federal Circuit recently issued a precedential decision, Egenera, Inc. v. Cisco Systems, Inc., No. 2023-1428 (Fed. Cir. July 7, 2025), that serves as a potent reminder of a key principle in patent litigation: address claim construction disputes squarely at the district court, or risk forfeiting them forever.
In a case involving sophisticated server virtualization technology, the court affirmed a complete victory for Cisco, not on a deep technical analysis, but on the appellant's failure to properly frame and preserve its arguments. The ruling highlights the potential procedural pitfalls that can ensnare even technologically complex disputes.
In Egenera, the Federal Circuit affirmed a district court's summary judgment of non-infringement on two claims and uphold a jury's verdict of non-infringement on two others.
The decision provides critical lessons for patent practitioners on the importance of litigation strategy, the preservation of issues for appeal, and the finality of a jury's verdict when supported by substantial evidence.
Background of the Dispute
The conflict centered on Egenera's U.S. Patent No. 7,231,430. The '430 patent generally describes a "processing platform" designed to overcome the cumbersome and error-prone process of manually reconfiguring server systems.
The '430 patent’s system allows an administrator to use software commands to select processors from a large pool and organize them into virtual networks, avoiding the need to physically rewire cables for different applications.
Egenera accused Cisco's successful Unified Computing System (UCS) of infringing claims 1, 3, 5, and 7 of the patent. Cisco's UCS platform also virtualizes server management, using software to group and deploy servers for specific needs.
The litigation traveled a long road, including a prior appeal that vacated an invalidity finding and remanded the case. On remand, the U.S. District Court for the District of Massachusetts granted summary judgment to Cisco, finding no infringement of device claim 1 and method claim 5.
The remaining claims, 3 and 7, proceeded to a jury trial, where the jury also found that Cisco did not infringe. Egenera appealed both the summary judgment decision and the district court's denial of its post-trial motions for judgment as a matter of law (JMOL) or a new trial.
The Court's Analysis: Unpacking the Central Legal Issues
The Federal Circuit's opinion addressed the summary judgment and the jury verdict separately, but a common theme of procedural discipline runs through both parts of the analysis.
The Waived "Emulation" Argument (Claims 1 and 5)
The summary judgment decision turned on a critical limitation in claims 1 and 5, which require that a "plurality of computer processors... emulate Ethernet functionality."
The district court had construed the term "computer processor" to mean a Central Processing Unit (CPU), a construction not at issue in this appeal. Cisco argued for summary judgment on the basis that in its UCS product, the CPUs do not "emulate" Ethernet functionality; rather, they simply use it. The actual emulation, Cisco contended, was performed by network interface cards (NICs), which are separate components.
The district court agreed, finding that "knowledge and use of a communications network is not emulation of the functionality of that network." On appeal, Egenera argued that this was an improper factual finding. The Federal Circuit, however, saw the issue differently. It recognized that the core of the disagreement was not factual but legal: what does it mean to "emulate" within the context of the claims? This is a classic question of claim construction.
Yet, Egenera had never asked the district court to construe the term "emulate." Worse, they had apparently framed the issue as purely factual in its summary judgment briefing and doubled down on that characterization on appeal, explicitly denying that it was seeking a new claim construction.
The Federal Circuit found this to be a fatal strategic error. The court stated its position unequivocally:
we will not address a claim construction issue for the first time when the appellant has failed to preserve that issue in the district court and has also failed to adequately present it to us for decision on appeal.
By failing to raise the claim construction dispute during the Markman process or at summary judgment, and then failing to argue it properly on appeal, Egenera had forfeited the argument. Forced to review the appeal on the terms Egenera had set—as a challenge to the sufficiency of the evidence—the court readily affirmed.
The evidence supported the conclusion that the CPUs only used Ethernet, while other components performed the emulation, meaning no reasonable jury could find infringement of those claims.
The Jury's Verdict on "Topology" (Claims 3 and 7)
Egenera's challenge to the jury's verdict of non-infringement on claims 3 and 7 fared no better. These claims require the platform's processors to be programmed to "establish the specified virtual local area network topology."
At trial, Cisco presented multiple non-infringement theories. Because the jury returned a general verdict, the verdict must be upheld if any single one of those theories is supported by substantial evidence.
The Federal Circuit focused on the "network topology" limitation. Cisco had presented expert testimony that its UCS system establishes network topology at the NICs, not at the CPUs (the "processors"). According to Cisco's witnesses, the UCS does not program the CPUs to establish the network configuration as required by the claim. The court found that the jury was entitled to credit this testimony over Egenera's arguments to the contrary.
Since a reasonable jury could have concluded that this limitation was not met, there was substantial evidence to support the verdict, and the district court correctly denied Egenera's motion for JMOL.
Key Takeaways and Practical Implications
The Egenera decision offers several crucial takeaways for patent owners and litigators.
Confront Claim Construction Disputes Directly. The most significant lesson is that ambiguity in claim language cannot be papered over. If a case turns on the meaning of a claim term, that dispute must be presented to the court for construction. Attempting to reframe a dispositive claim construction issue as a mere factual dispute is a high-risk strategy that can easily backfire. As seen here, it led to the forfeiture of Egenera's primary argument on appeal.
Litigants Define the Scope of Their Appeal. The Federal Circuit made clear it will not "embark" on its own claim construction analysis when the parties have not properly presented the issue. Egenera's insistence that the "emulate" issue was factual effectively tied the appellate court's hands, forcing an analysis on grounds unfavorable to Egenera. This highlights the need for a coherent strategy that aligns arguments at the trial and appellate levels.
The Importance of Timely Objections. Egenera's request for a new trial was denied in part because of its repeated failure to make timely objections. Whether it was a judge's stray remark during jury selection or allegedly improper testimony, the court noted that Egenera either failed to object or waited too long to do so. A pretrial motion in limine is not always sufficient to preserve an objection; counsel must always be vigilant and object contemporaneously when the offending evidence or argument is presented to the jury.
Conclusion
The Federal Circuit's opinion in Egenera v. Cisco will certainly be a case study in civil procedure and appellate practice within the patent law context.
It demonstrates that a failure to adhere to the basic rules of litigation—preserving arguments, making timely objections, and presenting a consistent legal theory—can be just as fatal to a patent infringement case as a flaw in the technical merits.
For practitioners, the message is clear: win or lose, build your case on a solid procedural foundation, because there are no do-overs on appeal.
Disclaimer: This is provided for informational purposes only and does not constitute legal or financial advice. To the extent there are any opinions in this article, they are the author’s alone and do not represent the beliefs of his firm or clients. The strategies expressed are purely speculation based on publicly available information. The information expressed is subject to change at any time and should be checked for completeness, accuracy and current applicability. For advice, consult a suitably licensed attorney and/or patent professional.