Keysight Technologies, Inc. IPR petition against the '437 patent

Case Overview

This matter is the inter partes review (IPR) front of a multi-forum patent war between Keysight Technologies, Inc. (IPR petitioner; defendant below) and Centripetal Networks, LLC (patent owner; captioned as Centripetal Networks, Inc. in some proceedings), a Portsmouth, Virginia-based cybersecurity patent holder that develops and licenses rule-based network-threat detection and packet-filtering technology. Keysight is a Santa Rosa, California operating company — the Agilent/HP test-and-measurement spinoff that expanded into network security and visibility testing via its 2017 Ixia acquisition — which sells network instrumentation and security products. The underlying infringement litigation is Centripetal Networks, Inc. v. Keysight Technologies, Inc., No. 2:22-cv-00002 (E.D. Va., filed Jan. 1, 2022), in which Centripetal alleges Keysight infringes the '437 patent and roughly ten other Centripetal patents (see Keysight's preliminary reply in IPR2023-00446, stating Centripetal "sued Petitioner asserting the '343 patent (and ten others) in January 2022"). The metadata's designation of Keysight as "Plaintiff" tracks its role as IPR petitioner; in the district-court case Centripetal is the plaintiff. Note also that the same '437 patent was asserted against Palo Alto Networks in the parallel case Centripetal Networks, LLC v. Palo Alto Networks, Inc., No. 2:21-cv-00137-EWH-RJK (E.D. Va.), where the '437 was one of several asserted Centripetal patents (10,567,437; 10,735,380; 10,530,903; 10,659,573; 10,931,797 — see the court's 2024 summary-judgment memorandum opinion on Justia/CourtListener).

The asserted patent, U.S. Patent No. 10,567,437, is one of Centripetal's packet-security-gateway patents. Based on claim 8 as quoted in the E.D. Va. summary-judgment opinion, it claims a system in which a packet security gateway receives network packets, makes a rule-based determination that a portion of the packets is suspect, and responds by configuring an associated LAN switch — e.g., by "modify[ing] a switching matrix of a local area network (LAN) switch" so the switch drops that portion of the received packets; the court's opinion also flags a dispute over whether the claims cover "a 'rule' that comprises only matching criteria." The accused technology in Centripetal's parallel PAN case was Palo Alto's next-generation firewall, Panorama, Cortex, AutoFocus, MineMeld, and DNS Security products (RPX). The specific Keysight product lines accused in the 2:22-cv-00002 action are not identified in the sources I could access, and I will not speculate beyond noting they are presumably Keysight network-security/visibility products from its Ixia line.

Procedural Posture and Why It Matters

Keysight petitioned for IPR of claims 1, 3, 5–8, 10, 12–15, 17, and 19–20 of the '437 patent; per the status table of "IPR Petitions filed by Keysight Technologies, Inc. ... on Asserted and Related Patents" filed as Exhibit 8 (Docket 329-8) to a joint status report in the PAN case on March 29, 2023, the '437 petition is marked "Institution Denied." The IPR docket number for the '437 petition was not located in the sources I retrieved (the exhibit itself shows the table but the petition number is not visible in the snippet; Keysight's related IPRs include IPR2023-00446 against the '343 patent, which was instituted on August 7, 2023, and IPR2023-00448 against U.S. Patent No. 11,012,474, described in the exhibit as "a grandchild of the '437 Patent"). The district-court cases sit in the Eastern District of Virginia (Norfolk/Newport News divisions) — the "rocket docket" — which is Centripetal's home forum (it is headquartered in Portsmouth, Virginia) and where it has repeatedly sued. The PAN case, 2:21-cv-00137, is assigned to Judge Elizabeth W. Hanes (EWH) with Magistrate Judge Robert J. Krask (RJK) (per later docket citations; Judge Roderick C. Young earlier handled the stay motion in that case per RPX). The Keysight case's current judge assignment was not confirmed in my sources.

Why the Case Is Notable

Centripetal is the paradigmatic high-stakes, litigation-driven cybersecurity patent owner: it obtained the largest patent verdict in U.S. history at the time — a $2.75 billion award against Cisco in E.D. Va. (later vacated on § 101 grounds, reinstated in part by the Federal Circuit, and followed by a retrial), and, per RPX, a Virginia jury returned a $151.1 million verdict for Centripetal against Palo Alto Networks. Against Keysight, the dispute is a textbook multi-front campaign: Centripetal filed suit in E.D. Va. (Jan. 2022); Keysight responded with waves of IPRs, an ITC defense, and European challenges. Reed Smith (Keysight's counsel) reports that Keysight has prevailed at the ITC (no violation, affirmed by the Federal Circuit), obtained PTAB decisions finding 185 claims across eight asserted Centripetal patents unpatentable, and won at the UPC and in German courts. The '437 IPR denial sits against that backdrop as an outlier outcome: several related Keysight petitions were instituted, and in the closely watched Keysight Tech., Inc. v. Centripetal Networks, Inc., IPR2022-01421, Director Kathi Vidal sua sponte vacated a PTAB § 325(d) denial and remanded, after which the Board instituted — underscoring how contested discretionary-denial issues (Advanced Bionics / "same or substantially the same prior art" presented during prosecution of continuation-family patents) have driven this dispute's IPR outcomes. The reason for the '437 institution denial (discretionary § 325(d)/§ 314(a) versus the merits) was not confirmed in my sources.

Sourcing caveats: I could not access PACER or the PTAB docket directly; findings rest on public excerpts from DocketAlarm, CourtListener, Justia, RPX, PTAB Litigation Blog, IP Update, JD Supra, and Reed Smith. Unverified or unlocated items — flagged above — include the '437 IPR docket number and denial decision text, the current judge in the Keysight district-court case, the specific accused Keysight products, and confirmation that the '437 patent (rather than only related patents) was asserted in the Keysight action.

Scope note / framing

Before the chronology, one important clarification grounded in the record: the metadata you supplied describes a PTAB proceeding — Keysight Technologies, Inc. as petitioner/IPR filer against U.S. Patent No. 10,567,437 ("the '437 patent," Centripetal Networks' "Methods and systems for protecting a secured network," issued 2020-02-18) — with institution denied. There is no district-court infringement action captioned Keysight v. Centripetal on the '437 patent. Based on the available record, the "infringement litigation" context in which this IPR and its "joint status report" arise is the Eastern District of Virginia litigation in which Centripetal asserted the same '437 claims against Palo Alto Networks, Inc. (PAN) — Centripetal Networks, Inc./LLC v. Palo Alto Networks, Inc., No. 2:21-cv-00137 (E.D. Va.) — while Keysight was separately sued by Centripetal on other family patents (Centripetal Networks, Inc. v. Keysight Technologies, Inc., No. 2:22-cv-00002 (E.D. Va., filed 2022-01-01)).

Note on the IPR number: consistent with your existing summary, I could not locate a PTAB case number for a Keysight-filed IPR directly on the '437 patent. The documented PTAB petition directly on the '437 patent — challenging the identical claim set later listed in the joint status report (claims 1, 3, 5–8, 10, 12–15, 17, 19–20) — is PAN's IPR2021-01153, which was denied institution. Keysight's own IPRs hit the broader Centripetal family (including the '474 patent, a grandchild of '437). Details below, with each item flagged as to sourcing.

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1. The underlying '437 infringement litigation: Centripetal v. Palo Alto Networks, 2:21-cv-00137 (E.D. Va.)

Filing & initial pleadings

• 2021-03 (approx.): Centripetal sued Palo Alto Networks in the Eastern District of Virginia, No. 2:21-cv-00137, before Judge Elizabeth W. Hanes (MJ Lawrence R. Leonard). An RPX/RPX Insight article dated 2022-01-24 describes this as the "March 2021 litigation filed against Palo Alto Networks [that] slogs through discovery." (RPX Insight, 2022-01-24.)
• The '437 patent was among the asserted patents. Centripetal's infringement contentions dated 2021-08-05 asserted '437 claims 1, 3, 5–8, 10, 12–15, 17, 19–20 — the identical claim set reflected in the IPR-status table at Docket No. 329-8 (filed 2022-03-29? — actually filed 2023-03-29) in the PAN case. (DocketAlarm, 2:21-cv-00137, Doc. 329-8.)

Parallel PTAB proceedings on the '437 (effect on litigation)

• ~2021-06: PAN filed IPR2021-01153, Palo Alto Networks, Inc. v. Centripetal Networks, Inc., petitioning for inter partes review of the '437 patent (grounds: obviousness over Jungck, alone or with RFC2003). (Petition reproduced at 2:21-cv-00137, Doc. 465-14.)
• Institution denied by the PTAB (per the IPR-status table at Doc. 329-8 in the PAN case: "Institution Denied" for the '437). Because the PTAB declined to institute, there was no IPR estoppel and no PTAB merits decision on the '437; validity of the '437 remained for the district court.
• Keysight's family-wide IPRs: Keysight (sued separately by Centripetal in 2:22-cv-00002 and defending ITC Investigation No. 337-TA-____) filed IPR petitions against eight of the eleven patents Centripetal asserted against Keysight (Doc. 54 in 2:22-cv-00002), and on 2023-01-06 filed IPR2023-00448 against the '474 patent — a "grandchild of the '437 Patent" (Doc. 329-8 in 2:21-cv-00137). The '474 IPR was instituted; the Board's Final Written Decision canceled all but five claims, and the Federal Circuit affirmed on 2026-07-21 in Keysight Techs., Inc. v. Centripetal Networks, LLC, Appeal No. 2025-1053 (nonprecedential), faulting Keysight for inadequately arguing the surviving dependent claims (PTABWatch, 2026-07).

Pre-trial motions of substance

• Section 101 / Rule 12(b)(6): Keysight (and Ixia) had earlier pursued § 101 dismissal of Centripetal family patents in the predecessor E.D. Va. litigation (No. 2:17-cv-00383-HCM-LRL; see, e.g., 2017-09-05 memorandum in support of motion to dismiss for unpatentability under § 101). In the PAN case itself, § 101 challenges were litigated at summary judgment (see below).
• Summary judgment (Jan. 2024) — from the Court's rulings described in Centripetal's post-trial opposition (Doc. 883, filed 2024-02-14):
  • On 2024-01-13, the Court granted PAN's motion for summary judgment of non-infringement of the '380 patent, mooting Centripetal's motions on that patent.
  • The Court denied Centripetal's summary-judgment motions seeking rulings of no invalidity under § 101 for the '903, '573, and '797 patents, finding genuine issues of material fact.
  • Centripetal's § 102/§ 103 and § 112 summary-judgment motions were denied as moot because PAN dropped those defenses for trial.
  • 2024-01-19: The Court denied Centripetal's motion for partial summary judgment that claim 8 of the '437 patent is not invalid for lack of written description, finding a genuine dispute (based on the competing expert testimony of Dr. Nielson for PAN and Dr. Goodrich for Centripetal, particularly regarding the "modify a switching matrix of a LAN" element). (Centrip Networks, LLC v. Palo Alto Networks, Inc., 2:21-cv-00137 (E.D. Va. Jan. 19, 2024); Casetext.) A related PAN summary-judgment motion on the same '437 written-description issue had earlier been denied.

Trial and verdict

• A jury trial was held in the PAN case in early 2024 (Centripetal's opposition to PAN's renewed JMOL, filed 2024-02-14, references sworn trial testimony, depositions, source code, and testing of accused products).
• The jury returned a verdict for Centripetal on the patents that went to trial — the '437, '903, '797, and '573 patents — including direct infringement of claim 8 of the '437 patent (per Centripetal's characterization in Doc. 883). I was not able to verify the verdict amount, exact verdict date, or the post-verdict damages award from sources available to me.

Post-trial motions

• PAN filed a renewed and additional motion for judgment as a matter of law (Dkt. 849). Centripetal opposed on 2024-02-14 (Doc. 883), arguing substantial evidence supported infringement (including of '437 claim 8), validity, and a reasonable-royalty damages theory using the Keysight license as a comparable — i.e., the license Centripetal granted Keysight to settle their earlier litigation (which expired 2021-12-31, immediately before Centripetal re-sued Keysight on 2022-01-01; RPX Insight, 2022-01-24).
• Post-trial outcome and any appeal: Not verifiable from the sources available (I did not locate a final judgment, fee ruling, or Federal Circuit appeal docket for the PAN case).

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2. The related Keysight litigation (2:22-cv-00002) — context for Keysight's IPRs

Because the metadata concerns a Keysight IPR, the parallel Keysight-front litigation is directly relevant context:

• 2022-01-01: Centripetal Networks, Inc. filed Centripetal Networks, Inc. v. Keysight Technologies, Inc., No. 2:22-cv-00002-AWA-DEM (E.D. Va., Norfolk), the day after a limited-term license that ended the parties' prior litigation lapsed (RPX Insight, 2022-01-24; Justia docket). Plaintiff's counsel: Stephen E. Noona (Kaufman & Canoles). Judge Arenda L. Wright Allen; MJ Douglas E. Miller.
• 2022-01-06: Service on Keysight's registered agent (Doc. 14). 2022-02-25: Keysight answered/moved — it filed a motion to dismiss for failure to state a claim (Docs. 25–26). (The § 101 dismissal strategy echoed Keysight's earlier 2017 motion in 2:17-cv-00383.)
• 2022-02/03–2022-07: Keysight moved to stay pending the ITC investigation and its IPR petitions; Centripetal opposed on 2022-07-01 (Doc. 45). The case's 11 asserted patents were '370, '917, '526, '572, '343, '062, '573, '009, '266, '456, and '474 — the '437 patent was not asserted against Keysight (Doc. 45).
• 2022-04: Centripetal filed its ITC § 337 complaint against Keysight (Keysight 10-K disclosures).
• Keysight filed IPRs on eight of the eleven patents asserted in 2:22-cv-00002, including IPR2022-01097 ('917; instituted 2022-12-19), IPR2022-01421 ('009; originally denied, Director Vidal vacated on 2023-08-24, and the Board instituted on 2023-11-06; Final Written Decision 2024-11-01; Centripetal appealed 2025-04-25), IPR2022-01525 ('526), IPR2023-00446 ('343), and IPR2023-00448 ('474) (Docs. 45 and 54 in 2:22-cv-00002; DocketAlarm PTAB dockets).
• 2023-12-05: The ITC issued its Notice of Determination of no Section 337 violation, terminating the investigation (Keysight 10-K; Reed Smith release). Centripetal appealed.
• The district court case was stayed pending finalization of the ITC and PTAB appeals (Keysight 10-K/10-Q disclosures).
• 2026-01: The Federal Circuit affirmed the PTAB's invalidation of all claims of one of the challenged patents (Keysight disclosures), and heard argument on the ITC findings and the PTAB findings on another patent.
• 2026-04-23: The Federal Circuit affirmed the ITC's no-violation determination in Centripetal's appeal and separately affirmed invalidity of most claims of one of the Centripetal patents (Law360, 2026-04-23; Reed Smith press release reporting Keysight's "major success," including PTAB decisions finding 185 claims across eight asserted patents unpatentable and multiple Federal Circuit affirmances).
• Keysight has also prevailed in parallel German/UPC proceedings against Centripetal family patents (Reed Smith release).

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3. Present posture as of 2026-09-05

• PTAB (the docket in your metadata — Keysight IPR against the '437): Institution denied; the PTAB docket number for a Keysight-filed '437 petition could not be located, and the documented institution-denied IPR on the '437 is PAN's IPR2021-01153. Because institution was denied, there is no estoppel and no Board merits decision on the '437 claims; the patent remained enforceable and its validity was decided (in Centripetal's favor at trial) in the PAN case.
• PAN case (where the '437 was actually asserted): Jury verdict for Centripetal on the '437 and three correlation patents (early 2024); PAN's renewed JMOL was pending as of 2024-02-14. Final judgment/fee/appeal status not verified from available sources.
• Keysight case (2:22-cv-00002): Stayed; the ITC no-violation determination has been affirmed by the Federal Circuit (2026), and Keysight has prevailed on essentially all challenged Centripetal family patents at the PTAB and on appeal.

Sourcing caveats

• Dates and events marked as "per Doc. ___" are drawn from the DocketAlarm/Justia/UniCourt/Casetext docket records cited above (E.D. Va. 2:21-cv-00137 Docs. 329-8, 465-14, 883; E.D. Va. 2:22-cv-00002 Docs. 14, 45, 54).
• I could not verify (from the searches available): the PTAB case number of any Keysight-filed IPR on the '437; the PAN-trial verdict date and damages amount; the PAN case's final judgment and appellate posture; and any Markman/claim-construction order in the PAN case (none surfaced in the sources retrieved).
• Company-disclosure and law-firm statements (Keysight 10-K/10-Qs; Reed Smith release) are secondary sources for the ITC, PTAB, and Federal Circuit outcomes and should be treated accordingly.

Threshold point about the procedural posture

This matter is not a patent infringement case with a "plaintiff." It is an inter partes review (IPR) before the PTAB in which Keysight Technologies, Inc. is the petitioner and Centripetal Networks, LLC/Inc. is the patent owner of U.S. Patent No. 10,567,437 (the "'437 patent"). (The underlying district-court litigation, Centripetal Networks, Inc. v. Keysight Technologies, Inc., No. 2:22-cv-00002 (E.D. Va.), is the infringement case—and there Centripetal is the plaintiff and Keysight the defendant.) Below I treat "plaintiff" as referring to Keysight, the party that filed the challenged petition.

Important sourcing caveat

The IPR case number for Keysight's petition against the '437 patent was not located in the available records (the case summary itself notes the number was never identified), and I could not retrieve the actual petition signature page or PTAB docket for that specific proceeding. The searches surfaced the status table (from Centripetal Networks, LLC v. Palo Alto Networks, Inc., No. 2:21-cv-00137 (E.D. Va.)) listing the '437 claims 1, 3, 5–8, 10, 12–15, 17, 19–20 with the notation "Institution Denied", but the same table ties Keysight's petition activity to a related grandchild patent (IPR2023-00448). Accordingly, I cannot confirm from a primary docket source which attorneys signed the '437 petition specifically.

What the record does confirm is the Reed Smith LLP team that represented Keysight throughout its multi-petition IPR campaign against Centripetal's patent family (including IPRs on related Centripetal patents filed in the same 2022–2023 window, and the Federal Circuit appeals). Counsel of record identified from those proceedings:

Keysight's counsel of record (Reed Smith LLP – IPR and Federal Circuit record)

1. Gerard M. Donovan — Lead/arguing counsel (appellate) — Reed Smith LLP, Washington, D.C.
   Argued for Keysight as appellee in Centripetal Networks, LLC v. Keysight Technologies, Inc., No. 24-2246 (Fed. Cir. Apr. 2, 2026), arising from Keysight's IPR win on U.S. Patent No. 10,284,526 (IPR2022-01525); also on the briefs in the related appeal of the '474-patent IPR. Long-running lead on Keysight's PTAB defense work.

2. Jonathan Iain Max ("Jonathan") Detrixhe — Counsel of record / petitioner's counsel (IPR stage) — Reed Smith LLP, San Francisco, CA
   Appeared as the Reed Smith attorney examining witnesses on behalf of petitioner Keysight in the Keysight v. Centripetal IPR depositions (e.g., IPR2023-00446 and IPR2022-01535 deposition transcripts, taken for the '343/'474/'062 patent proceedings); also listed on the Federal Circuit briefs. Reed Smith's San Francisco office (101 Second Street, Suite 1800) is the recurring IPR contact for Keysight.

3. Peter J. Chassman — Counsel of record (appellate/IPR support) — Reed Smith LLP, Houston, TX
   Listed on the Federal Circuit brief for appellee Keysight in No. 24-2246; part of the Reed Smith IPR trial team handling the Centripetal portfolio.

4. Michael John Forbes — Counsel of record (appellate/IPR support) — Reed Smith LLP, Houston, TX
   Listed with Mr. Chassman on the Federal Circuit brief for Keysight in No. 24-2246.

5. Jonah D. Mitchell — Counsel of record — Reed Smith LLP, San Francisco, CA
   Listed on the Federal Circuit brief for Keysight in No. 24-2246; active in the Centripetal IPR matters.

6. James Christopher Martin — Counsel of record — Reed Smith LLP, Pittsburgh, PA
   Listed on the Federal Circuit brief for Keysight in No. 24-2246.

Source: Centripetal Networks, LLC v. Keysight Technologies, Inc., Fed. Cir. No. 24-2246, opinion filed Apr. 2, 2026 (counsel listing); PTAB deposition transcripts in Keysight/Centripetal IPRs (e.g., IPR2023-00446, IPR2022-01535) showing "Reed Smith LLP" appearing for petitioner Keysight (Jonathan Detrixhe).

Local counsel in the parallel district case (if that is what was meant)

In the parallel E.D. Va. infringement case, Keysight (as defendant) filed notices through William R. Poynter (VSB #48672) — e.g., the Jan. 10, 2023 "Notice of Defendant's Filing of Additional Petitions for IPR" (Dkt. 54 in No. 2:22-cv-00002), which is also the document reporting the status of the Keysight IPR petitions on the asserted patents. I could not verify from the retrieved record which firm Mr. Poynter belongs to or whether he formally appeared as local counsel of record; treat him as a Virginia-licensed signatory for Keysight unless the docket is checked directly.

What I could not verify / did not find

• The specific PTAB docket number for the Keysight IPR on the '437 patent, and therefore the petition's signature page listing lead and back-up counsel under 37 C.F.R. § 42.8(b)(3), was not retrieved. If filings are not sealed, the lead/back-up counsel designation can be confirmed from the petition's signature block or the PTAB "Notice of Filing Date" once the docket number is identified.
• No Keysight in-house counsel appeared as counsel of record in any of the retrieved PTAB or Federal Circuit papers; the record reflects outside counsel (Reed Smith) throughout.
• I did not find any indication the underlying papers are sealed.

Bottom line: If the '437 petition followed Keysight's other Centripetal IPRs (which the surrounding docket strongly suggests), the attorneys of record were the Reed Smith LLP team — principally Jonathan Detrixhe (San Francisco) at the IPR stage, with Gerard Donovan (Washington, D.C.), Peter Chassman and Michael Forbes (Houston), Jonah Mitchell (San Francisco), and James Martin (Pittsburgh) on the associated appellate work. But because the '437 IPR number itself was never identified, I cannot point to that petition's signature page, and this identification should be treated as circumstantial rather than docket-verified.

Threshold clarification — who "the defendant" is here

This matter, per the case metadata, is Keysight's IPR petition against the '437 patent — an inter partes review at the PTAB in which Keysight is the petitioner (metadata's "Plaintiff") and Centripetal Networks is the patent owner. An IPR has no formal "defendant."

The only actual "patent infringement case" in this dispute — and the only place where a party is formally a defendant — is the underlying district-court action:

Centripetal Networks, Inc. v. Keysight Technologies, Inc., No. 2:22-cv-00002-AWA-DEM (E.D. Va., filed Jan. 1, 2022), before Judge Arenda L. Wright Allen and Magistrate Judge Douglas E. Miller, defendant = Keysight Technologies, Inc.

Accordingly, the primary answer below identifies Keysight's counsel of record in that infringement case (docket-verified). Because the earlier "Plaintiff representatives" section treated the metadata's "plaintiff" as the IPR petitioner, I also flag at the end what the record shows if "defendant" was instead meant to mean the patent owner defending the patent (Centripetal).

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Defendant Keysight Technologies, Inc. — counsel of record (docket-verified)

Sources: E.D. Va. docket in 2:22-cv-00002 — Dkt. 24 (order granting pro hac vice, Feb. 16, 2022), Dkt. 40 (joint status report signature block, Mar. 28, 2022), Dkt. 49 (notice of change of address), Dkt. 54 (notice re IPR petitions, Jan. 10, 2023); Unicourt party summary; Reed Smith attorney bios.

Supporting appellate/PTAB members of the same Reed Smith defense team (not appearing as district-court counsel of record but part of the unified Keysight defense, covered in the "Plaintiff representatives" section): Gerard M. Donovan (Washington, D.C.; Reg. No. 67,771 — argued for Keysight before the PTAB in IPR2023-00446 and at the Federal Circuit in No. 24-2246), Jonathan Detrixhe (San Francisco), Peter J. Chassman and Michael J. Forbes (Houston), and James C. Martin (Pittsburgh).

In-house counsel: None identified as appearing of record in the retrieved district-court or PTAB filings; the defense has been run by outside counsel (Reed Smith + Kaleo Legal).

Case-status note: Keysight prevailed on its motion to stay the E.D. Va. action pending the IPRs (per Reed Smith bios; docket order not independently retrieved), and the ITC leg ended in a no-violation finding affirmed by the Federal Circuit. I could not access PACER directly, so current-term (2025–2026) substitutions or withdrawals of counsel cannot be ruled out without a live docket check.

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If "defendant" was intended to mean the patent owner defending the patent (Centripetal)

Because the metadata lists Keysight as the "Plaintiff" (petitioner), some readers may intend the adverse party — Centripetal Networks, LLC (f/k/a Centripetal Networks, Inc.), the patent owner/respondent. Its counsel of record is well documented in the parallel Keysight/Centripetal IPRs (IPR2023-00446, IPR2023-00445, IPR2022-01421, et al.):

PTAB / patent-owner side (consistent team across the Centripetal IPR defenses):

• James Hannah — Lead counsel for patent owner — Kramer Levin Naftalis & Frankel LLP (now Herbert Smith Freehills Kramer after the 2025 merger), Redwood Shores, CA (Reg. No. 56,369). Lead on Centripetal's PTAB defenses; earlier secured the record ~$2.75B verdict for Centripetal against Cisco in E.D. Va. (source: firm bio; IPR2023-00446 mandatory-notice and Preliminary Response signature blocks).
• Jenna Fuller — back-up counsel — Kramer Levin/HSF Kramer, Redwood Shores, CA (Reg. No. 74,212).
• Jeffrey H. Price and Jeffrey Eng — Kramer Levin/HSF Kramer, New York, NY (Reg. Nos. 69,141 and 63,189).
• Scott M. Kelly, Bradley C. Wright, John R. Hutchins — Banner & Witcoff, Ltd., Washington, DC (Reg. Nos. 65,121; 38,061; 43,686) — patent-prosecution-side PTAB support for Centripetal.

District court (where Centripetal is plaintiff, not defendant): Stephen E. Noona (Kaufman & Canoles, P.C., Norfolk, VA; VSB #25367), Kevin O'Donnell (Henry & O'Donnell P.C., Alexandria, VA; VSB #30086) as Virginia counsel, with Kramer Levin attorneys Paul J. Andre, Lisa Kobialka, James Hannah, Hannah Lee, and Kris Kastens (Redwood Shores/Menlo Park) as pro hac vice counsel for Centripetal (Dkt. 10, 49).

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Key caveats

• The specific PTAB docket number for Keysight's '437 IPR petition remains unlocated (the case status table in the PAN action, Dkt. 329-8, lists "'437 … Institution Denied" without the case number). Consequently, the signature page of the '437 petition — and thus the petition-specific designation of Keysight's lead/back-up counsel and Centripetal's patent-owner counsel in that exact proceeding — could not be retrieved. The counsel identified above are docket-verified for the related Keysight/Centripetal IPRs and the district-court case; the '437-specific designations are inferred from the parties' consistent counsel teams and should be confirmed against the PTAB docket once the case number is identified.
• Kramer Levin's 2025 combination with Herbert Smith Freehills means firm names/office addresses on older filings (e.g., "Kramer Levin Naftalis & Frankel LLP, 333 Twin Dolphin Drive, Redwood Shores, CA") may now appear under the "Herbert Smith Freehills Kramer" banner.
• No filings appear to be sealed, but I did not access PACER or the PTAB docket directly; verification of any counsel substitutions post-2024 requires a live docket check.