⚖ Oral Arguments, with Context

The Federal Circuit hears Corrigent's patent dispute with Cisco. Corrigent sued Cisco, alleging that Cisco's communications equipment infringed its patents on packet forwarding and hidden-failure detection. An idle connection can fail without disrupting current traffic, leaving the problem unnoticed until that connection is needed. The appeal has three distinct branches. First, the four-hundred patent concerns packet forwarding and address checking. Corrigent will argue that the trial court wrongly required certain steps to happen in a fixed order, excluding checks performed when a packet enters the system. Cisco will argue that the claim language requires the relevant checks on the outgoing side, which its accused products do not perform. Second, the three-sixty-nine patent concerns testing idle connections for hidden faults. The district court held the asserted claims patent-ineligible, treating them as an abstract test-and-report idea implemented with generic components. Corrigent will argue that the particular arrangement and testing method improve the equipment's operation; Cisco will argue that the claims lack an inventive improvement beyond conventional hardware and testing. Third, the six-oh-two patent concerns encoding a physical tunnel port's serial number in a packet label. Corrigent will argue that its infringement evidence should have gone to the jury. Cisco will argue that identifying a virtual connection does not supply the particular physical-port identifier the claims require. Keep these questions separate: what a claim means, whether its subject matter is patent-eligible, and whether the accused product satisfies the claim.

Corrigent Corp. v. Cisco Systems, Inc. (No. 25-2036) — U.S. Court of Appeals for the Federal Circuit, argued November 5, 2026.