Petitioner v. Sandpiper Cdn LLC

This is an inter partes review (IPR) proceeding, IPR2026-00180, before the Patent Trial and Appeal Board (PTAB), challenging the validity of US Patent 10701173. The Petitioner is Microsoft Corporation, a major technology operating company. The Patent Owner and defendant is Sandpiper Cdn LLC. Sandpiper Cdn LLC is the successor to Sandpiper Networks, which pioneered content delivery network (CDN) technologies in the 1990s, and it manages an extensive portfolio of over 400 patent assets related to CDN technology, having acquired them from Level 3 Communications (later Lumen Technologies). Sandpiper Cdn LLC has been identified as a Delaware plaintiff, with its parent company being Theseus LF Asset Holdings, LLC, suggesting it operates as a patent assertion entity (PAE).

The patent at issue, US Patent 10701173, is titled "Content Delivery Network Caching Methods". It generally describes a method for a node within a Content Delivery Network to serve cached content. Its purported novelty lies in a "late-binding" approach, where the current cache policy governing the content is determined dynamically at the time a user request is made, rather than when the content is initially stored in the cache. This IPR was filed on December 24, 2025, and challenges claims 1-14 of the patent.

The procedural posture places this case before the Patent Trial and Appeal Board, an administrative body within the USPTO, rather than a district court. IPRs serve as a common mechanism for parties accused of patent infringement to challenge the validity of asserted patents based on prior art patents and printed publications, often as a parallel or precursor to district court litigation. This case is notable due to Sandpiper Cdn LLC's pattern of asserting its extensive CDN patent portfolio, including against major technology companies like Google for its Cloud CDN and Media CDN offerings, and against Comcast in the Eastern District of Texas. Microsoft's challenge via IPR signifies a strategic response by an operating company to the assertion of patents covering fundamental CDN infrastructure, which is critical for delivering internet content for services such as streaming video platforms.

The patent infringement litigation involving U.S. Patent 10,701,173 primarily centers around the Inter Partes Review (IPR) proceeding IPR2026-00180 and a parallel district court case, Sandpiper CDN, LLC v. Microsoft Corporation, in the Eastern District of Texas.

Here is a chronological overview of the key legal developments and current posture:

Parallel District Court Litigation

2024-11-01: Sandpiper CDN, LLC v. Comcast Cable Communications, LLC et al. (E.D. Tex. Case No. 2:24-cv-00886-JRG-RSP)
Sandpiper CDN, LLC initiated a patent infringement lawsuit against Comcast Cable Communications, LLC and related entities in the Eastern District of Texas, asserting claims from five method patents. Patent 10,701,173 was not explicitly listed among the asserted patents in the available search snippets for this case.

2025-01-13: Comcast Files Motion to Dismiss or Transfer Venue
Defendant Comcast filed a motion to dismiss for improper venue or, alternatively, to transfer the case to the Eastern District of Pennsylvania.

2025-02-11: Comcast Corporation Dismissed
The parties stipulated to the dismissal of Defendant Comcast Corporation.

2025-06-26: Sandpiper CDN, LLC v. Microsoft Corporation (E.D. Tex. Case No. 2:25-cv-00664)
Sandpiper CDN, LLC filed a patent infringement complaint against Microsoft Corporation in the Eastern District of Texas. This lawsuit specifically asserts U.S. Patent 10,701,173, along with five other former Level 3 Communications patents, against Microsoft. The complaint targets Microsoft's Azure platform, including its content delivery infrastructure and services such as Azure CDN Standard, Azure CDN Standard from Edgio, Azure CDN Premium from Edgio, and Azure Front Door Standard and Premium.

2025-08-14: District Court Denies Comcast's Motion to Dismiss/Transfer
The Eastern District of Texas denied Comcast's motion to dismiss or transfer for improper venue, finding that Sandpiper had properly established venue.

2025-10-28: Joint Motion for Protective Order Filed in Microsoft Case
Sandpiper CDN, LLC filed a joint motion for entry of a protective order in the Sandpiper v. Microsoft case.

2025-10-29: Protective Order Signed in Microsoft Case
A protective order was signed by Magistrate Judge Roy S. Payne in Sandpiper v. Microsoft.

2025-11-25: Microsoft Files Unopposed Motion for Extension of Time for Discovery
Microsoft Corporation filed an unopposed motion for an extension of time to complete discovery in Sandpiper v. Microsoft.

2025-12-09: Federal Circuit Denies Comcast's Mandamus Petition
The Federal Circuit denied Comcast Cable Communications, LLC's petition for a writ of mandamus seeking to overturn the district court's denial of its motion to dismiss or transfer for improper venue in the Comcast litigation.

2025-12-08: Document Filed in Error in Microsoft Case
An additional attachment to a main document (Doc. 50, a Response in Opposition to Motion) was filed in error in Sandpiper v. Microsoft.

Parallel PTAB IPR Proceeding

2025-12-24: IPR2026-00180 Petition Filed
Microsoft Corporation filed an inter partes review (IPR) petition, IPR2026-00180, challenging claims 1-14 of U.S. Patent 10,701,173. Sandpiper CDN, LLC is the Patent Owner in this proceeding. The petition argues for unpatentability based on obviousness over various prior art references, including O'Rourke, O'Rourke in view of MS-MSSO, O'Rourke and Blumofe, Middleton alone, and Middleton and MS-MSSO.

Current Posture (as of 2026-05-29)

• IPR2026-00180: The IPR proceeding is currently pending before the Patent Trial and Appeal Board. An institution decision by the PTAB is expected in late 2026 or early 2027, as institution decisions typically occur within 12 to 18 months of the petition filing. Recent USPTO policy changes, effective October 20, 2025, and March 11, 2026, place the decision to institute IPR trials with the USPTO Director and introduce U.S. manufacturing activity as a discretionary factor for institution.
• Sandpiper CDN, LLC v. Microsoft Corporation (E.D. Tex. Case No. 2:25-cv-00664): The district court litigation against Microsoft is active. Key upcoming events include a Claim Construction Hearing scheduled for October 5, 2026, and a Case Management Conference on March 1, 2027. The IPR proceeding, if instituted, may lead to a motion to stay the district court litigation, though such stays are discretionary.

Here is the counsel of record representing the plaintiff, Sandpiper Cdn LLC, in Sandpiper CDN, LLC v. Microsoft Corporation (E.D. Tex. Case No. 2:25-cv-00664):

Lead Counsel:

• Ryan D. Dykal
  • Firm: Boies Schiller Flexner LLP
  • Office Location: Washington, D.C. (Common for Boies Schiller Flexner, though specific office for Dykal not immediately specified in provided snippets).
  • Experience Note: Appears as counsel for Sandpiper CDN, LLC in multiple patent infringement cases, including the initial complaint against Microsoft.
• Mark D. Schafer
  • Firm: Boies Schiller Flexner LLP
  • Office Location: Likely one of Boies Schiller Flexner's offices (e.g., Washington, D.C., New York).
  • Experience Note: Listed as counsel for Sandpiper CDN, LLC in the Microsoft case.
• Connor Coupe
  • Firm: Boies Schiller Flexner LLP
  • Office Location: Likely one of Boies Schiller Flexner's offices.
  • Experience Note: Listed as counsel for Sandpiper CDN, LLC in the Microsoft case.
• Carolyn E. Drell
  • Firm: Boies Schiller Flexner LLP
  • Office Location: Likely one of Boies Schiller Flexner's offices.
  • Experience Note: Listed as counsel for Sandpiper CDN, LLC in the Microsoft case.
• Philip Eckert
  • Firm: Boies Schiller Flexner LLP
  • Office Location: Likely one of Boies Schiller Flexner's offices.
  • Experience Note: Listed as counsel for Sandpiper CDN, LLC in the Microsoft case and noted for a document filing error.

Local Counsel:

• J. Mark Mann
  • Role: Local Counsel
  • Firm: Mann | Tindel | Thompson / MT2 Law Group
  • Office Location: Tyler, TX
  • Experience Note: Board Certified in Personal Injury Trial Law; experienced in complex civil litigation, including patent litigation, practicing in the U.S. District Court for the Eastern District of Texas.
• Andy Tindel
  • Role: Local Counsel
  • Firm: Mann | Tindel | Thompson / MT2 Law Group
  • Office Location: Tyler, TX
  • Experience Note: Practices in patent infringement actions, commercial litigation, and appellate matters in the Eastern District of Texas; served as a law clerk for a U.S. District Judge in the Eastern District of Texas.
• G. Blake Thompson
  • Role: Local Counsel
  • Firm: Mann | Tindel | Thompson / MT2 Law Group
  • Office Location: Tyler, TX
  • Experience Note: Practices in business litigation, personal injury, and intellectual property litigation.

Co-Counsel (Potentially Local or Co-Lead):

• Garrett C. Parish
  • Firm: Miller Fair Henry PLLC
  • Office Location: Tyler, TX (Miller Fair Henry PLLC is based in Tyler, TX, suggesting a local role).
  • Experience Note: Listed as counsel for Sandpiper CDN, LLC in the Microsoft case.
• Andrea Leigh Fair
  • Firm: Miller Fair Henry PLLC
  • Office Location: Tyler, TX.
  • Experience Note: Listed as counsel for Sandpiper CDN, LLC in the Microsoft case.

I'll research the counsel representing the opposing party. Note there's a framing wrinkle here worth flagging: the IPR caption styles Sandpiper as the "defendant" (patent owner), but the prior section already covered Sandpiper's counsel as "plaintiff representatives" in the parallel district court case. So the natural complement is Microsoft's counsel — as Petitioner in the IPR and as the accused defendant in the co-pending E.D. Tex. litigation. Let me search both tracks.

Good — I'm getting a clear picture. Let me confirm which firm represents which party in the IPRs and nail down the district court defense team.

Defendant-Side Counsel of Record — IPR2026-00180 / Sandpiper CDN, LLC v. Microsoft Corp. (E.D. Tex. 2:25-cv-00664)

Framing note (please read before the table)

There is an inherent caption ambiguity here that affects who counts as "the defendant." The PTAB caption in the case metadata (Petitioner v. Sandpiper Cdn LLC) names Sandpiper CDN as the respondent/patent owner, while the co-pending infringement action is styled Sandpiper CDN, LLC v. Microsoft Corporation, where Microsoft is the defendant. The prior "Plaintiff representatives" section covered only Sandpiper's district court team (Boies Schiller Flexner + Miller Fair Henry/MT2). To avoid duplication and to fill the real gap, this section covers Microsoft's counsel — which is the same party on both tracks (Petitioner in the IPR, Defendant in E.D. Tex.) — and then adds Sandpiper's IPR counsel (Sterne Kessler), which the earlier section did not capture.

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1. IPR2026-00180 — Counsel for Petitioner Microsoft Corporation (Perkins Coie LLP)

This is the operative team for the case as docketed. The Petition's own Notice of Counsel and Service Information (Dec. 24, 2025) designates Perkins Coie as Petitioner's counsel, with the service address Microsoft-Sandpiper-IPR@perkinscoie.com:

Sources: Petition/IPR2026-00180 Notice of Counsel (via USPTO PTAB docket summaries, ai-lab-cl-prod.azurewebsites.net/case/ptab/IPR2026-00180/doc/summary/1); PTAB email correspondence in IPR2026-00174 (ptacts.uspto.gov, petition 1558761, "RE: IPR2026-00174 … Request for Authorization to File Corrected Ex-1003," Jan. 7, 2026); Power of Attorney in IPR2026-00174 appointing Perkins Coie for Petitioner Microsoft.

Note on the Director decision: Paper 15 in IPR2026-00180 (May 6, 2026), denying Sandpiper's request for discretionary denial, is signed by the panel's counsel-of-record block with the Perkins Coie team as "For Petitioner" and Sterne Kessler as "For Patent Owner," confirming the alignment. (Jones Day PTAB Litigation Blog, Sept. 4, 2026, https://www.jonesday.com/en/insights/2026/09/failure-to-cite-own-prior-art-tanks-patent-owners-discretionary-denial-request-iptab-litigation-blogi; decision PDF at https://www.ptablitigationblog.com/wp-content/uploads/2026/06/PTAB-IPR2026-00180-15.pdf.)

In-house counsel: No Microsoft in-house attorney has appeared by name on the IPR2026-00180 filings in the public record I could reach; the powers of attorney in the related Microsoft–Sandpiper IPRs are executed by a corporate officer (name redacted/truncated in the available copies), not an in-house attorney of record. I would not attribute an in-house name without a clean source.

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2. Parallel District Court — Counsel for Defendant Microsoft Corporation (Sandpiper CDN, LLC v. Microsoft Corp., E.D. Tex. 2:25-cv-00664)

Per the PACER Monitor docket-entries listing and Law360 firm/attorney case pages, Microsoft's defense team is Fish & Richardson P.C. (lead) with a Tyler, TX local-counsel firm:

Sources: PACER Monitor docket listing for 2:25-cv-00664 (https://www.pacermonitor.com/public/case/58736526/Sandpiper_CDN,_LLC_v_Microsoft_Corporation); Law360 firm pages for Claire Chang, Bailey K. Benedict, and Joseph R. Dorris (all listing "June 26, 2025 — Sandpiper CDN, LLC v. Microsoft Corporation, Texas Eastern").

Experience note: Fish & Richardson is a longstanding Microsoft outside-counsel firm in patent matters — e.g., it appeared for Microsoft in Hypermedia Navigation LLC v. Microsoft Corp., N.D. Cal. No. 4:18-cv-00670 (Jonathan Lamberson, Indranil Mukerji, Ricardo Bonilla et al. as "Attorneys for Defendant Microsoft Corporation"), and Microsoft's 2018 stipulation in that case was signed by F&R (Betty H. Chen). That pattern is consistent with the F&R-led defense here.

Sealing/appearance caveat: The available docket excerpts do not include formal "lead counsel" designations under the E.D. Tex. local rules, and the substitute/amended complaints and willfulness briefing (Dkt. 43, 56, 57; order entered July 13, 2026 overruling Microsoft's objections) do not resolve role labels. If a formal designation order exists, I could not retrieve it.

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3. Complementary: Patent Owner Sandpiper CDN's IPR counsel (Sterne Kessler Goldstein & Fox PLLC)

Not covered in the earlier "Plaintiff representatives" section (which listed only the Boies Schiller/Miller Fair Henry district-court team). In the Microsoft–Sandpiper IPR family, Sandpiper (Patent Owner/respondent) is represented by Sterne Kessler:

• Jason D. Eisenberg (Reg. No. 43,447) — Lead counsel, Sterne Kessler Goldstein & Fox PLLC, 1101 K St. NW, 10th Fl., Washington, D.C. — designated "Lead Counsel for Patent Owner" in Microsoft v. Sandpiper, IPR2026-00095, Patent Owner's Mandatory Notices (Nov. 7, 2025).
• Daniel S. Block (Reg. No. 68,395), Kristina Caggiano Kelly (Reg. No. 58,164), Timothy L. Tang (Reg. No. 75,187), Todd C. Thurheimer — back-up counsel, same firm/address.

Source: Microsoft Corp. v. Sandpiper CDN, LLC, IPR2026-00095, Patent Owner's Mandatory Notices (via Docket Alarm), and the Sterne Kessler counsel block appearing as "For Patent Owner" on Paper 15 in IPR2026-00180.

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4. Contradiction to flag against the earlier sections

The prior "Key legal developments" section states: "An institution decision by the PTAB is expected in late 2026 or early 2027." Newer search results contradict this. The PTAB case summary for IPR2026-00180 shows Institution 06/12/26 — Status: Trial Instituted, Outcome: Instituted (https://ai-lab-cl-prod.azurewebsites.net/case/ptab/IPR2026-00180/microsoft-corp-v-sandpiper-cdn-llc), and Director Squires' Paper 15 of May 6, 2026 denied Sandpiper's discretionary-denial request and referred the Petition to the merits, consistent with a June 2026 institution. The "expected late 2026/early 2027" language should be updated to reflect that the trial was instituted on June 12, 2026, and that the district court stay calculus has therefore shifted. (I did not independently pull the Notice of Decision on Institution PDF, so I'd verify the exact institution date against PTAB Paper 16/17 before publishing.)

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Sourcing summary and limits

• High confidence: Perkins Coie = Petitioner Microsoft in IPR2026-00180 (Petition Notice of Counsel + POA + PTAB correspondence); Sterne Kessler = Patent Owner Sandpiper in the Microsoft–Sandpiper IPRs (Patent Owner Mandatory Notices); Fish & Richardson attorneys on the E.D. Tex. docket (Law360 + PACER Monitor).
• Lower confidence / flagged: exact lead-vs-back-up designations in the district court; Deron Dacus's formal "local counsel" title; the firms of Riley James Green and Cheryl Wang; and any in-house Microsoft counsel. I did not fabricate designations where the record was silent.
• Not verified: whether an appearance/designation order exists in 2:25-cv-00664 or the later-filed 2:26-cv-00681 (also Sandpiper v. Microsoft, complaint signed by Ryan Dykal for Sandpiper) that formally names a lead counsel for Microsoft.