Ex parte reexamination of U.S. Patent No. 10,931,797

I'll research this matter, though I note the metadata describes an ex parte reexamination at the USPTO (90/019,561), not a district court litigation. Let me verify the details.

The first search results connect U.S. Patent 10,931,797 to Centripetal Networks' litigation against Palo Alto Networks (E.D. Va.). Let me dig deeper into the patent, the reexamination, and the parties.

I have strong initial leads. Now let me verify the litigation's procedural posture, the reexamination requester and prior art, and current status.

Case Overview and Background

Important framing correction. This matter is not a patent infringement litigation — it is an ex parte reexamination before the USPTO (Control No. 90/019,561) of U.S. Patent No. 10,931,797, requested on July 1, 2024, in which the Office found a substantial new question of patentability (SNQ) as to claims 1, 12, and 17. The underlying infringement dispute is Centripetal Networks, LLC v. Palo Alto Networks, Inc., No. 2:21-cv-00137 (E.D. Va.), which produced a January 31, 2024 jury verdict of $151.5M for Centripetal (Reuters; Kramer Levin press release; RPX cites $151.1M) later reduced post-trial. There is, accordingly, no "court," "division," or "judge" for the reexam itself: it is being handled by USPTO Examiner Eric B. Kiss (Class 370, Art Group 3992). Aggregated USPTO docket data shows a non-final office action mailed February 10, 2026, a patent-owner response/amendment filed April 10, 2026, and a Notice of Intent to Issue a Reexamination Certificate mailed June 10, 2026, with the file shown as "terminated" — which conflicts with the metadata's "ongoing" status and should be verified on PAIR/PRPS before relying on it.

Parties, technology, and patent. The patent owner is Centripetal Networks, Inc./LLC (Portsmouth, NH; described by Reuters as Reston, VA-based), a network-security technology company that has become one of the most prominent high-stakes patent enforcers in cybersecurity — most famously winning a $2.75B judgment against Cisco Systems (the largest U.S. patent award at the time), which the Federal Circuit vacated due to judicial disqualification and which Cisco later won on retrial. The third-party requester in the ex parte reexam is not identified in the sources reviewed here and should be confirmed from the public reexam file; given the procedural context (post-verdict, against the same claims Palo Alto Networks challenged in a single PGR during the litigation), a Palo Alto Networks-linked request is plausible but is not verified, and note that PGR estoppel (35 U.S.C. § 325(e)) could complicate any direct PAN request. In the underlying case, Centripetal accused Palo Alto Networks' (PAN's) next-generation firewalls supporting the "Automated Correlation Engine," Cortex XDR and Cortex XSOAR when combined, and Cortex XSIAM of infringing the '797 patent (see jury verdict form, E.D. Va. ECF No. 851). U.S. Patent No. 10,931,797, titled "Correlating Packets in Communications Networks" (issued Feb. 23, 2021; continuation of the family yielding U.S. 10,659,573), is directed to correlating packets traversing a network boundary: a system logs packets a network device receives from a host in a first network and packets it transmits to a host in a second network, correlates the transmitted and received packets by comparing those log entries, generates one or more filtering rules based on that correlation, and provisions a packet-filtering device with those rules — enabling automated, cross-boundary threat-intelligence-driven rule creation.

Procedural posture, venue, and significance. The reexam (90/019,561) is the administrative tail of a litigation that was fiercely contested at the PTAB and in the Eastern District of Virginia — Centripetal's favored forum (it also sued Cisco and Keysight there, and its Markman opinion drew on prior ITC constructions of the same family). PAN filed validity challenges against all 13 originally asserted patents — IPRs against twelve and a single PGR against the '797 — and the PTAB invalidated six patents in 2023, trimming the case to the '437, '380, '573, '903, and '797 patents before the January 2024 trial (RPX). At trial, Judge Elizabeth W. Hanes (E.D. Va., Norfolk Division; case initially handled by Judge Roderick C. Young, who granted the PTAB stay in March 2022, with reassignment to Judge Hanes in August 2022) presided over a jury that found PAN's products infringed claims 1, 12, and 17 of the '797 (the same claims now in reexam), awarded a $151.5M lump sum, and found no willfulness; in October 2024, Judge Hanes granted JMOL of non-infringement on the '437 patent and reduced the award (sources vary: RPX says $116.3M; Law360 says $113.6M), with both sides appealing to the Federal Circuit in November 2024. The case is notable for several converging reasons: (1) the reexam is a post-verdict validity attack aimed squarely at the claims underpinning a nine-figure judgment; (2) the same '797 claims were also the subject of PAN's PGR, and in a closely watched related Federal Circuit decision (reported January 2025) the appellate court vacated and remanded a PTAB obviousness decision in this patent family for failure to adequately explain its motivation-to-combine analysis; and (3) Centripetal's enforcement campaign — the Cisco $2.75B verdict, the PAN verdict, and parallel IPR/PGR warfare — has made it a bellwether for both cybersecurity patent monetization and the durability of large jury awards against networking giants, with the PTAB and ex parte reexam channels serving as the principal checkpoints on its correlation-patent family.

Important threshold point about the "case"

The matter supplied in the metadata — Ex parte Reexamination Control No. 90/019,561, U.S. Patent No. 10,931,797 (USPTO) — is not a patent infringement litigation. It is an examiner-driven USPTO reexamination. As a result, many of the procedural categories you ask about (complaint/answer, Markman, discovery disputes, trial, verdict, JMOL) do not and cannot occur inside this proceeding. What the searches did verify is that the '797 patent is Centripetal's and sits at the center of parallel district-court and PTAB proceedings that the reexamination intersects. Below is everything verifiable from the retrieved sources, organized chronologically, followed by a category-by-category mapping. Items I could not confirm from the captured search results are expressly flagged as unverified — I have not fabricated dates or rulings.

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Verified chronology

2021-02-23 — Patent issues

U.S. Patent No. 10,931,797 B2, "Correlating packets in communications networks," issued to Centripetal Networks, Inc. (inventors David K. Ahn, Peter P. Geremia, Sean Moore, Robert T. Perry). (Sources: Unified Patents patent page; PatentLeaderboard entry; DocketAlarm copy of USPTO reexam order, Doc. 993-4 in E.D. Va. case 2:21-cv-00137.)

2021-08-03 — Parallel PTAB PGR filed

Palo Alto Networks, Inc. v. Centripetal Networks, Inc., PGR2021-00108 (PTAB), a post-grant review of the '797 patent, was filed — within the 9-month post-grant window. (Source: DocketAlarm PTAB docket search listing "PGR2021-00108 … Patent 10931797," petitioner Palo Alto Networks, patent owner Centripetal Networks.) The institution decision and final written decision were not retrievable in the searches performed; that outcome is unverified and is the single most important open item for assessing estoppel/impact on any litigation.

2024-07-01 — Ex parte reexamination requested

Reexamination request filed for the '797 patent (Control No. 90/019,561). The requester's identity does not appear in the retrieved USPTO form (the "Requester (if third party requester)" field is blank in the excerpt), so I cannot confirm whether it was Palo Alto Networks, an anonymous third party, or another entity. (Source: USPTO "Order Granting Request for Ex Parte Reexamination," PTOL-471G, produced as Doc. 993-4 in the district court case.)

2024-09-26 — Reexamination granted

The USPTO (Examiner Eric B. Kiss, Art Unit 3992) mailed its Order Granting Request for Ex Parte Reexamination, finding a substantial new question of patentability affecting claims 1, 12, and 17 of the '797 patent. Patent-owner statement and requester-reply time bars were set per 37 C.F.R. §§ 1.530(b)/1.535 (no § 1.136(a) extensions). (Sources: USPTO order reproduced at DocketAlarm; consistent with the case metadata you supplied.)

2024-10-31 — Reexamination order filed in the parallel district-court litigation

The USPTO reexamination order was filed as Document 993-4 in Centripetal Networks, Inc. v. Palo Alto Networks, Inc., No. 2:21-cv-00137-EWH-LRL (E.D. Va.) — the district-court patent case over (among others) the '797 patent. This confirms the reexamination was being actively used in that litigation (e.g., for stays, invalidity contentions, or disclosure obligations), though the specific filing's purpose is not described in the retrieved snippet. (Source: DocketAlarm PDF of Doc. 993-4, case 2:21-cv-00137-EWH-LRL.)

Present posture

Per the controlling case summary you supplied, the ex parte reexamination is ongoing; no reexamination certificate or final office action has been confirmed.

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Category-by-category mapping to your request

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Candid assessment of gaps

Because the tool-run hit its step limit, I could not verify: the requester's identity in 90/019,561, the PGR2021-00108 institution and final written decision, the docket history of Centripetal v. Palo Alto Networks (2:21-cv-00137) — including its filing date, asserted claims/patents, Markman order, trial or verdict — and any interplay rulings (stay pending reexam/PGR). Those would need PACER (E.D. Va.), the PTAB's PRPS system, and USPTO PAIR/patent center lookups to pin down with dates.

If you want, the next pass should target: (1) PTAB PGR2021-00108 institution/FWD; (2) the E.D. Va. docket 2:21-cv-00137 complaint date and dispositive docket entries; and (3) any stay motion citing 90/019,561 or PGR2021-00108.

Important threshold point: this is not a patent infringement case, so there is no "plaintiff"

Before identifying counsel, the premise of the question needs correcting. The docket you've given me — Control No. 90/019,561, filed July 1, 2024, at the USPTO — is an ex parte reexamination, not a district-court patent infringement action. In an ex parte reexamination under 35 U.S.C. §§ 301–307 there are no "plaintiffs" or "defendants." The participants are:

• Patent owner, who may file statements and amendments; and
• Third-party requester, who files the request but is not a party once the Director orders reexamination (37 C.F.R. § 1.535) and drops out of the proceeding (unless the patent owner files a statement triggering a limited reply).

Accordingly, there is no plaintiff-side counsel of record to report. What I can report — and where the "plaintiff" framing likely comes from — is set out below.

What the record actually shows

The patent at issue. U.S. Patent No. 10,931,797 B2, "Correlating Packets in Communications Networks," issued Feb. 23, 2021, to Centripetal Networks, Inc. (Portsmouth, NH) — inventors David K. Ahn, Peter P. Geremia, Pierre Mallet III, Sean Moore, and Robert T. Perry. It is a continuation in a family reaching back to 2015. Prosecution attorney of record was Banner & Witcoff, Ltd. (this is prosecution counsel, not reexamination counsel, and should not be mistaken for litigation counsel). Centripetal Networks, Inc. later changed name to Centripetal Networks, LLC (recorded assignment, reel/frame 062446/0660).

The reexamination proceeding (90/019,561). Filed 7/1/2024 as a third-party-requester ex parte reexam; the USPTO docket reflects a reexamination ordered (the case summary says the request was granted with a substantial new question found affecting claims 1, 12, and 17). Docket data retrieved today shows the proceeding has advanced well beyond "ongoing": a Reexamination Non-Final Action mailed 2/10/2026, a patent-owner amendment/response filed 4/10/2026, and — per the Docket Alarm/GAE tracking page — a Notice of Intent to Issue a Reexamination Certificate mailed 6/10/2026 (i.e., the reexam has been terminated on the merits, with a certificate pending). A parallel reexam of a family patent, 90/019,563, followed a near-identical path (non-final action 1/2/2026, response 3/2/2026, NIRC mailed 5/6/2026), and in that file a new Power of Attorney and 37 C.F.R. § 3.73 showing of ownership were filed 12/15/2025, with a change-in-POA communication on 12/19/2025 — indicating new counsel of record came in for one of the participants in late 2025. The snippets do not name those attorneys, and I will not guess.

Why "patent infringement" appears in this context. The '797 patent is a litigation patent. The most directly relevant case found is Centripetal Networks LLC v. Palo Alto Networks Inc., No. 2:21-cv-00137 (E.D. Va.) (Judge Elizabeth W. Hanes, MJ R. J. Krask), where the '797 patent was submitted into the record (Docket 360-7, filed 7/14/2023). Centripetal has also litigated related family patents against Cisco (E.D. Va.; IPR2018-01559 was filed by Cisco against a family patent), and Palo Alto Networks filed IPR2021-01520 against family members. If the "plaintiff" you mean is Centripetal Networks, LLC in the E.D. Va. litigation, its counsel of record are on the PACER docket for 2:21-cv-00137, which I could not retrieve in the available searches. I have not verified any attorney names for Centripetal in that case and decline to state any from memory.

Bottom line / explicit limitations

• No counsel list can be given for "plaintiffs" because there is no plaintiff in 90/019,561. The ex parte reexam format does not have lead/local/of-counsel roles of the kind you'd find in an infringement suit.
• Counsel of record before the USPTO for the patent owner (Centripetal Networks, LLC) in 90/019,561 and for the third-party requester are identifiable only from the reexamination file itself — USPTO PAIR/Patent Center (assignment and POA records) or the Docket Alarm/GEA transaction history. The public snippets show POA activity (12/15/2025 in the companion 90/019,563) but do not disclose names.
• Counsel for Centripetal as plaintiff in the parallel E.D. Va. case (2:21-cv-00137) require PACER or a docket service (Docket Alarm, CourtListener) pull of the complaint and notices of appearance; those were not available in the searches performed.
• Status note: The metadata's "granted; ongoing" appears stale as of today (2026-09-04). The USPTO docket indicates the reexam concluded with a Notice of Intent to Issue a Reexamination Certificate mailed June 10, 2026.

If you can confirm whether you actually want (a) the patent owner's USPTO counsel in the reexam, (b) the third-party requester's identity/counsel, or (c) Centripetal's plaintiff counsel in the E.D. Va. litigation, I can target the PACER/PTAB/Patent Center searches accordingly.

I'll start by clarifying the nature of this proceeding and searching for related litigation involving U.S. Patent No. 10,931,797.

The metadata points to an ex parte reexamination (90/019,561) rather than a district court infringement case. But the search results reveal the underlying dispute: Centripetal Networks, Inc. v. Palo Alto Networks, Inc., No. 2:21-cv-00137 (E.D. Va.) — and that Palo Alto Networks filed the reexamination request against Centripetal's '797 patent. Let me dig into both proceedings to identify counsel accurately.

Threshold issue: this USPTO docket is not a patent infringement case, and has no "defendants"

Before naming attorneys, I need to flag a mismatch in the question. Control No. 90/019,561 is an ex parte reexamination at the USPTO of U.S. Patent No. 10,931,797 — not a district-court patent infringement case. It has no defendants in the litigation sense. The only parties are:

• Patent owner: Centripetal Networks, LLC (the '797 patent is assigned to Centripetal).
• Third-party requester: Palo Alto Networks, Inc. (PAN), which filed the reexamination request on July 1, 2024, challenging claims 1, 12, and 17. The request expressly identifies the sole related district-court case as Centripetal Networks, Inc. v. Palo Alto Networks, Inc., No. 2:21-cv-00137 (E.D. Va.), and states PAN is the requester. (See the request PDF: "on behalf of Palo Alto Networks, Inc. ('Requester') hereby requests ex parte reexamination of claims 1, 12, and 17 ... of U.S. Patent No. 10,931,797"; patent owner's address of record for service is Banner & Witcoff, Ltd., 1100 13th St. NW, Washington, DC.)

So there is no "defendant's counsel of record" to identify in the reexamination itself. If your question actually targets the parallel E.D. Va. infringement suit in which the '797 patent is asserted — where Palo Alto Networks, Inc. is the defendant — the counsel of record below applies.

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Counsel for the defendant (Palo Alto Networks, Inc.) in the related E.D. Va. infringement action — Centripetal Networks, Inc./LLC v. Palo Alto Networks, Inc., No. 2:21-cv-00137 (E.D. Va., filed Mar. 12, 2021)

Source: Defendant's own filings — Dkt. 54 (May 27, 2021 notice, signature block) and Dkt. 860 (Feb. 7, 2024 joint notice of deposition transcripts, defendant's signature block) — both on DocketAlarm, plus the UniCourt party listing.

Virginia (local/resident) counsel — McGuireWoods LLP

• Robert W. McFarland — McGuireWoods LLP, Norfolk, VA (VSB No. 24021). Lead signatory on PAN's Virginia filings and the local EDVA anchor for the defense; long-tenured EDVA/IP litigator.
• David E. Finkelson — McGuireWoods LLP, Richmond, VA (VSB No. 44059). Co-signatory Virginia counsel on PAN filings.

Pro hac vice trial counsel — Norton Rose Fulbright US LLP

• Brett C. Govett — Norton Rose Fulbright, Dallas, TX. Listed first among PAN's PHV trial counsel in Dkt. 54/860; experienced patent trial lawyer.
• Jacqueline G. Baker — Norton Rose Fulbright, Dallas, TX.
• Richard S. Zembek — Norton Rose Fulbright, Houston, TX.
• Eric B. Hall — Norton Rose Fulbright, Houston, TX.
• Daniel S. Leventhal — Norton Rose Fulbright, Houston, TX.
• Daniel A. Prati — Norton Rose Fulbright, Houston, TX.
• Stephanie N. DeBrow — Norton Rose Fulbright, Austin, TX (appears in Dkt. 54; in the UniCourt party listing).

Pro hac vice trial/appellate counsel — Ropes & Gray LLP

• James R. Batchelder — Ropes & Gray, East Palo Alto, CA. Veteran patent litigator; has also handled PAN's related PTAB/Federal Circuit work against Centripetal (e.g., Fed. Cir. No. 23-2027, where he and Andrew Radsch appeared for PAN as appellee in the IPR appeal).
• Andrew T. Radsch — Ropes & Gray, East Palo Alto, CA. Same role on the PAN/Centripetal PTAB and appellate docket.
• Carolyn L. Redding — Ropes & Gray, East Palo Alto, CA (listed in Dkt. 54).
• Josef Byks Schenker — Ropes & Gray, New York, NY (added by Dkt. 860, Feb. 2024, as the case went to trial).
• Related appellate counsel: Douglas H. Hallward-Driemeier — Ropes & Gray, Washington, DC — argued for PAN as appellee in the related Federal Circuit IPR appeal (Centripetal Networks, LLC v. Palo Alto Networks, Inc., No. 23-2027, decided Oct. 22, 2025), though that appeal concerned a different Centripetal patent (U.S. 9,917,856), not the '797 patent.

Note on roles: The docket does not use "lead counsel" labels in the entries I reviewed. McFarland/McGuireWoods functioned as EDVA local/resident counsel (Virginia-bar signatories), while Norton Rose Fulbright and Ropes & Gray appeared pro hac vice as the trial team. I would not assign a single "lead" label without the court's scheduling orders or the parties' designation filings.

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Who represents PAN in the reexamination itself?

In an ex parte reexamination there is no formal "counsel of record" docket in the PACER sense, and the requester largely exits after the order is granted. The July 1, 2024 request was filed on behalf of Palo Alto Networks, Inc. as Requester, but my search snippets did not capture the attorney signature block on the request (the DocketAlarm PDF shows the caption, the PAN Litigation disclosure, and the Banner & Witcoff service address, but not the signing attorney). I therefore cannot responsibly name the signing attorney for the requester without pulling the full request or the CRU file wrapper. Based on PAN's pattern of representation in the related IPRs and Federal Circuit appeals (Ropes & Gray's Batchelder/Radsch/Hallward-Driemeier), Ropes & Gray is the likely filer — but that is inference, not verified fact. Patent owner Centripetal's address of record for the reexamination is Banner & Witcoff, Ltd. (Washington, DC), per the request's certificate of service.

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Status caveat

The case metadata says "granted; ongoing." A USPTO reexamination docket aggregator (DocketUpdate/gaelfront) shows that by mid-2026 the CRU had mailed a Notice of Intent to Issue a Reexamination Certificate (June 10, 2026) after a non-final rejection (Feb. 10, 2026) and a patent-owner response/amendment (Apr. 10, 2026) — meaning the reexamination may effectively be in its final administrative stage (certificate not yet confirmed published in my sources). Since your instruction makes the metadata controlling only for party names, court, case number, and patent, I flag the discrepancy rather than treating either source as conclusive on status.

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Bottom line

• In reexamination 90/019,561 there is no defendant; the correct "adverse" parties are patent owner Centripetal Networks, LLC (counsel of record: Banner & Witcoff, Ltd., Washington, DC) and requester Palo Alto Networks, Inc. (signing counsel not verified from public snippets).
• In the underlying infringement case (E.D. Va. 2:21-cv-00137), the defendant Palo Alto Networks, Inc. is represented by the McGuireWoods (McFarland, Finkelson — Virginia/local), Norton Rose Fulbright (Govett, Baker, Zembek, Hall, Leventhal, Prati, DeBrow), and Ropes & Gray (Batchelder, Radsch, Redding, Schenker) attorneys listed above, per Dkt. 54 and Dkt. 860.
• If filings are sealed or counsel changes post-verdict/appeal are relevant, note that the trial concluded in early 2024 (a reported ~$152M verdict for Centripetal), and I have not verified any post-trial substitution of defendant's counsel; that would require checking later docket entries on PACER/CM/ECF, which were beyond what my searches captured.