Before Lourie, Hughes, and Stark. Appeal from the U.S. District Court for the Eastern District of Texas.

Summary: An infringement judgment is only sufficiently “final” to be immune from a later finding of unpatentability if the litigation has moved to a stage that leaves nothing for the court to do but execute the judgment.

This case was before the Federal Circuit for the second time. Packet sued NetScout in the Eastern District of Texas for infringing various patents. Previously, the district court found that NetScout willfully infringed and that no asserted claim was unpatentable or invalid, and granted pre- and post-suit damages, enhanced damages, and an ongoing royalty for future infringement. In the first appeal, the Federal Circuit affirmed the district court’s infringement and validity determination but reversed the award of some of the monetary damages, remanding the case back to the district court to reconsider damages. During the pendency of the remand, the Patent Trial and Appeal Board issued final written decisions in several 3^rd-party IPRs that found all of the claims asserted by Packet against NetScout unpatentable. Packet appealed the Board’s decision. Following issuance of the final written decisions, NetScout moved to dismiss Packet’s infringement case, or in the alternative stay the case pending resolution of Packet’s appeal. The district court denied the motion to dismiss or stay and entered an amended final judgment regarding the litigated issues on remand from the first appeal. NetScout appealed.

After NetScout appealed, the Federal Circuit affirmed the Board’s final written decision of unpatentability in the 3^rd-party IPRs. On appeal, the same 3-judge panel determined that Packet’s patent infringement was moot because Packet’s infringement judgment was not sufficiently final to be immune from the unpatentability affirmation. The Federal Circuit explained that an infringement judgment is only sufficiently “final” to be immune from a later finding of unpatentability if the litigation has moved to a stage that leaves nothing for the court to do but execute the judgment. Packet’s infringement judgment was not sufficiently “final” after the Federal Circuit initially affirmed the infringement judgment because the district court had to reconsider the awarded damages on remand, which is more than “nothing … but execute the judgment.” Packet’s infringement judgment was also not sufficiently “final” after the district court issued the amended judgment because NetScout’s appeal was non-frivolous.

Editor: Sean Murray

PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.