Centripetal Networks, LLC v. Cisco Systems, Inc.

Centripetal Networks, LLC v. Cisco Systems, Inc. The Federal Circuit affirmed the district court's noninfringement judgment on all three patents. The '193 claims require two-stage filtering, with source/destination filtering only at stage one; "responsive to" in the '806 claims requires but-for causation of ceasing processing (and the contrary argument was forfeited); and the '176 findings were not clearly erroneous. Patent owner statements in an IPR response about a two-stage process were used to limit claim scope, and arguments not fairly presented to the district court will be treated as forfeited, even in a case on remand after a recusal-driven vacatur. Affirmed. Background: after the first appeal vacated the earlier infringement judgment because the judge should have recused, a new judge reviewed the record under Rule 63 and found no infringement of the '193, '806 and '176 patents. A Rule 54(b) judgment was entered, and the '856 patent remained undecided. '193 patent: the specification and Centripetal's IPR statements show the claims require two distinct filtering stages. Stage one is 5-tuple source/destination filtering, and stage two filters by method or type of communication. Citing Aylus, the court held IPR statements can be used for claim construction. Cisco's quarantine rule filters only by source and destination, and Centripetal conceded at argument that it loses under this construction. The court rejected Centripetal's notice-based request for remand on the '193 patent, because Cisco had argued the two-stage requirement throughout trial briefing and at the Rule 63 hearing. It also found no evidence that the quarantine rule filters by a particular type of data transfer, as opposed to products that could be modified to do so. '806 patent: Centripetal's argument that "responsive to" requires causation only of the rule-swap sequence as a whole was forfeited because it was not fairly presented below. Alternatively, the claim language and specification require the signal to be the but-for cause of ceasing processing, and Cisco's devices cease processing as part of normal operation, not in response to a signal. '176 patent: no clear error in finding no correlation of NetFlow ingress and egress records, since Centripetal limited its accusation to NetFlow at the Rule 63 hearing and its Syslog/Webflow theory depended on proxy data that was not present. Stealthwatch also only issues alerts, and a human administrator decides whether to issue a quarantine tag, so it does not automatically generate and provision rules. claim construction infringement waiver / forfeiture remand non-precedential