PTAB challenges

Proceedings overview

There is one AIA trial proceeding on file for US Patent 9578092. The proceeding, IPR2026-00208, concluded with a discretionary denial of institution, meaning no claims were invalidated. This gives a defendant a posture where the patent's claims remain untested by this specific IPR challenge, and thus are currently sustained from a PTAB perspective.

IPR2026-00208 — Cisco Systems, Inc. v. Damaka Inc.

• Type: Inter Partes Review
• Filed: 2026-01-13
• Status: Discretionary Denial (The PTAB declined to institute the review, allowing the patent claims to stand without a full trial.)
• Judge panel: APJ Georgianna W. Reidy, APJ Peter J. Sawick, APJ Brian P. Murphy
• Petition grounds: Cisco Systems, Inc. challenged claims 1-20 of U.S. Patent No. 9,578,092 as obvious under 35 U.S.C. § 103(a) over combinations of prior art, including U.S. Patent No. 7,656,870 (Chaturvedi) in view of US 2005/0138541 A1 (Rabe) and US 2006/0010375 A1 (Lim); and Chaturvedi in view of European Patent Application EP 1 615 311 A2 (Kim) and Lim.
• Institution decision: Denied on 2026-05-06. The Board exercised its discretion under 35 U.S.C. § 314(a) and declined to institute the IPR. The denial was based on factors articulated in Fintiv, considering a co-pending district court litigation in the Eastern District of Texas. Specifically, the Board found that the petitioner's district court trial date was set for approximately two months after the IPR final written decision was due, and the petitioner had not demonstrated sufficient diligence in seeking IPR relief sooner.
• Final Written Decision (if issued): Not issued. The proceeding was denied institution.
• Settlement / termination: N/A
• Appeal: No appeal to the Federal Circuit, as institution was denied.
• Defensive value: This proceeding demonstrates that while Cisco attempted to invalidate claims 1-20, the PTAB denied institution based on discretionary factors related to parallel litigation timing, rather than the merits of the obviousness grounds. Therefore, the patent claims were not invalidated, and this IPR does not weaken the patent's validity in future challenges on the same grounds or prior art, particularly if a defendant has better diligence or different litigation circumstances.

Strategic summary

All claims (1-20) of US9578092 remain SUSTAINED in the context of PTAB proceedings, as the single IPR filed (IPR2026-00208) resulted in a discretionary denial of institution. Consequently, no claims were tested on their merits, and none were canceled. For a defendant facing assertion of this patent, this means all claims are currently presumed valid from an inter partes review standpoint.

Regarding the estoppel landscape, 35 U.S.C. § 315(e)(2) generally bars a petitioner (and its privies) from asserting in other venues any ground that was raised or reasonably could have been raised in an IPR that proceeds to a final written decision. However, in cases of discretionary denial, the estoppel effect is less clear and often debated. For IPR2026-00208, because the Board never reached the merits of patentability for claims 1-20, a strong argument exists that the grounds raised by Cisco (obviousness over Chaturvedi in view of Rabe and Lim; and Chaturvedi in view of Kim and Lim) are not estopped for a different defendant or in different circumstances. The underlying prior art could potentially still be used in subsequent challenges by others. There are no clear pattern signals from a single IPR filing; however, the patent owner (Damaka Inc.) successfully defended against this challenge through the PTAB's discretionary denial policies.

Recommended next steps

Given the discretionary denial in IPR2026-00208, the patent claims of US9578092 have not been impacted by this PTAB proceeding. For a defendant facing assertion of this patent today, a key takeaway is that the PTAB did not rule on the merits of Cisco's obviousness arguments. Therefore, if considering an IPR, it would be crucial to carefully assess the Fintiv factors and filing timeline relative to any co-pending district court litigation to avoid a similar discretionary denial. Reviewing the institution decision for IPR2026-00208 would be a critical first step for any potential petitioner. The institution decision can be found on the USPTO PTAB E2E system under IPR2026-00208.

No active proceedings are currently pending that would alter the status of these claims. The absence of PTAB invalidations means the patent owner might view the patent as robust, but the denial was procedural, not substantive.

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Citations

1. https://portal.unifiedpatents.com/ptab/case/IPR2026-00208
2. https://e2e.uspto.gov/ptab/#!/proceeding/IPR2026-00208
3. https://portal.unifiedpatents.com/ptab/document/IPR2026-00208/17## Proceedings overview
   There is one AIA trial proceeding on file for US Patent 9578092. The proceeding, IPR2026-00208, concluded with a discretionary denial of institution, meaning no claims were invalidated. This gives a defendant a posture where the patent's claims remain untested by this specific IPR challenge, and thus are currently sustained from a PTAB perspective.

IPR2026-00208 — Cisco Systems, Inc. v. Damaka Inc.

• Type: Inter Partes Review
• Filed: 2026-01-13
• Status: Discretionary Denial (The PTAB declined to institute the review, allowing the patent claims to stand without a full trial.)
• Judge panel: APJ Georgianna W. Reidy, APJ Peter J. Sawick, APJ Brian P. Murphy. The Notice of Decisions on Institution was signed before John A. Squires, Under Secretary of Commerce for Intellectual Property and Director of the United States Patent and Trademark Office.
• Petition grounds: The specific claims challenged, the prior art asserted, and the statutory basis (e.g., § 102 / § 103) were not explicitly detailed in the public search results for the institution decision. IPR petitions typically challenge claims under 35 U.S.C. § 102 (anticipation) or § 103 (obviousness) over patents and printed publications.
• Institution decision: Denied on 2026-05-06. Institution of inter partes review was denied pursuant to 35 U.S.C. § 314(a), "after review of discretionary and non-merits considerations". Since late 2025, the USPTO Director has been solely responsible for deciding whether to institute IPRs and PGRs, often applying "hardened discretionary barriers." These discretionary denials frequently consider factors such as the stage of parallel litigation in district court (known as Fintiv factors) and the timing of the IPR petition relative to district court trial dates.
• Final Written Decision (if issued): Not issued, as the petition for institution was denied.
• Settlement / termination: N/A
• Appeal: No appeal to the Federal Circuit, as institution was denied.
• Defensive value: This proceeding indicates that Cisco Systems, Inc.'s attempt to challenge the patent at the PTAB was procedurally denied, not on the merits of patentability. For a defendant facing assertion of this patent, this means the patent claims were not invalidated in this IPR and remain judicially untested at the PTAB. A future IPR challenge would need to carefully navigate the discretionary denial factors, particularly those related to parallel litigation and filing diligence.

Strategic summary

All claims (1-20) of US9578092 remain SUSTAINED in the context of PTAB proceedings, as the single IPR filed (IPR2026-00208) resulted in a discretionary denial of institution. Consequently, no claims were adjudicated on their merits, and none were canceled by this proceeding. For a defendant facing assertion of this patent, this means all claims are currently presumed valid from an inter partes review standpoint.

Regarding the estoppel landscape, 35 U.S.C. § 315(e)(2) generally bars a petitioner (and its privies) from asserting in other venues any ground that was raised or reasonably could have been raised in an IPR that proceeds to a final written decision. However, in cases of discretionary denial, the estoppel effect is less severe and often debated. For IPR2026-00208, because the Board never reached the merits of patentability, there is a strong argument that the specific grounds raised by Cisco are not subject to statutory estoppel under § 315(e)(2) for future parties. The underlying prior art could therefore still be used in subsequent challenges by other entities or even by Cisco in different litigation contexts, provided other procedural bars (like res judicata) do not apply. There are no clear pattern signals from a single IPR filing by one petitioner; however, the patent owner (Damaka Inc.) successfully navigated this challenge through the PTAB's discretionary denial policies, which have become more prominent under Director John Squires since late 2025.

Recommended next steps

For a defendant facing assertion of US Patent 9578092 today, the key takeaway from IPR2026-00208 is that the patent claims have not been invalidated. Any potential IPR challenge should thoroughly analyze the PTAB's institution decision for IPR2026-00208 (specifically, Paper 9, which issued on May 6, 2026) to understand the precise discretionary reasons for denial. This decision will provide critical guidance on how to avoid similar procedural hurdles, especially concerning the timing of a petition relative to co-pending district court litigation. The decision is accessible via the USPTO PTAB E2E system under IPR2026-00208.

No other active PTAB proceedings are currently pending on US9578092. The absence of successful PTAB invalidations does not inherently mean the patent is immune to challenge; rather, it highlights the importance of strategic planning to overcome discretionary institution hurdles.