CommWorks v. Sangoma: PBX & Fax-to-Email Patents Dismissed With Prejudice in 179 Days
CommWorks Solutions, LLC filed suit against Sangoma Technologies and Sangoma US in the Eastern District of Texas, asserting two patents covering cloud PBX and facsimile-to-email functionality against Sangoma’s PBXact Cloud system. The parties jointly moved to dismiss all claims with prejudice just 179 days after filing — each side bearing its own costs.
A swift, bilateral exit from E.D. Texas: reading the Sangoma dismissal
CommWorks Solutions, LLC — a patent assertion entity holding IP in unified communications and fax-over-internet technology — filed Case No. 2:23-cv-00534 in the Eastern District of Texas on 20 November 2023, targeting Sangoma Technologies, Inc. and its US subsidiary Sangoma US, Inc. The suit alleged infringement of US8533278B2 and US8224909B2 through Sangoma’s PBXact Cloud platform and its facsimile-to-email (FEM) functionality. The case was assigned to Judge Rodney Gilstrap, one of the most experienced patent jurists in the federal system.
On 17 May 2024 — just 179 days after filing — the parties filed a Joint Motion to Dismiss stipulating that all claims and causes of action in Case No. 2:23-cv-00534 be dismissed with prejudice. The court accepted the stipulation, terminated Sangoma Technologies and Sangoma US as defendants, and ordered each party to bear its own costs, attorneys’ fees, and expenses. The with-prejudice designation means CommWorks is permanently barred from re-asserting the same claims against Sangoma on these patents in any future action.
The 179-day timeline is notably short for E.D. Texas patent litigation, where cases frequently run two to three years before trial. The mutual cost-bearing order and joint motion structure suggest a negotiated resolution — whether that involved a license, a covenant not to sue, or simply a commercial decision to exit is not disclosed in the public record. Notably, a related Lead Case (No. 2:23-cv-533) was explicitly kept open by Judge Gilstrap at the time of dismissal, indicating broader CommWorks enforcement activity remains active in the same forum.
Filing to Dismissed with Prejudice in 179 days
179 days — resolved well below the median E.D. Texas patent case duration, suggesting early negotiation
Dismissed with prejudice: what the joint stipulation means for both parties
Dismissal with prejudice extinguishes all future claims on these patents
A dismissal with prejudice under Rule 41 is a final adjudication on the merits for res judicata purposes. CommWorks cannot re-file these specific claims against Sangoma Technologies or Sangoma US on US8533278B2 or US8224909B2. Because the motion was joint, both parties consented — distinguishing this from a court-ordered involuntary dismissal and suggesting a coordinated resolution outside the public record.
Permanent bar on re-filingSangoma secures permanent protection from these patent claims
Sangoma Technologies and Sangoma US exit the litigation with the strongest possible procedural protection: no further exposure to CommWorks on these two patents. Whether this came via a license, a covenant not to sue, or a purely strategic exit is not public. The mutual cost-bearing order suggests neither party extracted a financial concession large enough to offset fees — or that any payment was embedded in undisclosed commercial terms.
Clean exit, no cost awardCommWorks forfeits the right to re-assert these claims against Sangoma
CommWorks permanently surrenders its ability to sue Sangoma on the asserted patents. For a patent assertion entity, agreeing to a with-prejudice dismissal typically signals either that a licensing arrangement was reached (making further litigation unnecessary) or that continued prosecution was commercially unviable. The public record does not disclose any monetary settlement, licence fee, or covenant terms.
Re-assertion permanently barredRelated Lead Case stays open — broader CommWorks campaign continues
Judge Gilstrap’s order explicitly preserves Lead Case No. 2:23-cv-533, indicating this dismissal resolves only one member case in a multi-defendant campaign. Other defendants in the unified communications and cloud PBX space should monitor CommWorks’ enforcement posture. The asserted patents — covering cloud PBX routing and fax-to-email delivery — remain valid and enforceable against all other parties.
Enforcement campaign ongoingFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | CommWorks Solutions, LLC | Company | Patent assertion entity — holder of US8533278B2 and US8224909B2 in unified communications IPSearch in Eureka ↗ |
| Defendant | Sangoma Technologies, Inc. | Company | Sangoma Technologies, Inc. and Sangoma US, Inc. — cloud PBX and unified communications providerSearch in Eureka ↗ |
| Co-Defendant | Sangoma US, Inc. | Company | Search in Eureka ↗ |
| Plaintiff counsel | Andrey Belenky | Attorney | Counsel for CommWorks Solutions, LLCSearch in Eureka ↗ |
| Plaintiff counsel | Brandon Gregory Moore | Attorney | Counsel for CommWorks Solutions, LLCSearch in Eureka ↗ |
| Plaintiff counsel | Catherine Susan Bartles | Attorney | Counsel for CommWorks Solutions, LLCSearch in Eureka ↗ |
| Plaintiff counsel | Dmitry Kheyfits | Attorney | Counsel for CommWorks Solutions, LLCSearch in Eureka ↗ |
| Plaintiff counsel | Stafford Grigsby Helm Davis | Attorney | Counsel for CommWorks Solutions, LLCSearch in Eureka ↗ |
| Plaintiff law firm | Kheyfits Belenky LLP | Law Firm | Representing CommWorks Solutions, LLCSearch in Eureka ↗ |
| Plaintiff law firm | The Stafford Davis Firm (Tyler) | Law Firm | Representing CommWorks Solutions, LLCSearch in Eureka ↗ |
| Defendant counsel | Jon Bentley Hyland | Attorney | Counsel for Sangoma Technologies, Inc.Search in Eureka ↗ |
| Defendant law firm | HILGERS, GRABEN PLLC | Law Firm | Representing Sangoma Technologies, Inc.Search in Eureka ↗ |
| Presiding judge | Judge Rodney Gilstrap | Judge | Texas Eastern District CourtSearch in Eureka ↗ |
Official order — verbatim text
The court’s order mirrors the parties’ joint stipulation almost verbatim, accepting and acknowledging the dismissal with prejudice without issuing independent findings on infringement or validity. This language confirms the court made no merits determination — the dismissal is purely consensual. For Sangoma, the res judicata effect is absolute on these claims. For CommWorks, the order’s explicit carve-out preserving Lead Case No. 2:23-cv-533 confirms that broader enforcement activity in the same court continues uninterrupted.
US8533278B2 & US8224909B2 — cloud PBX routing and facsimile-to-email systems
US8533278B2 (App. No. 13/490,403) and US8224909B2 (App. No. 12/369,785) cover technology in the unified communications domain, specifically addressing cloud-based PBX call routing architectures and the conversion and delivery of facsimile communications via email infrastructure. These patents sit at the intersection of legacy telephony and modern cloud communications — a technically active space as enterprises migrate from on-premise PBX hardware to hosted UCaaS solutions. The application dates place these inventions in the late 2000s to early 2010s, predating the broad SaaS UCaaS market.
For the cloud PBX and hosted communications sector, these patents represent meaningful freedom-to-operate risk. Facsimile-to-email functionality is pervasive across UCaaS platforms — Sangoma’s PBXact Cloud is one of dozens of products offering FEM features. CommWorks’ willingness to assert both patents together in a multi-defendant E.D. Texas campaign suggests a coordinated licensing strategy. Any vendor shipping hosted PBX, FEM, or integrated voicemail-fax routing should treat these patents as enforcement-active and conduct claim-level FTO analysis.
Should your UCaaS product be cleared against US8533278B2 and US8224909B2?
Any company building or shipping cloud PBX infrastructure, hosted fax-to-email pipelines, or unified messaging integrations should assess exposure to these two patents. The Sangoma case demonstrates that CommWorks is actively enforcing this portfolio in E.D. Texas — a jurisdiction plaintiff-friendly on patent claims. Product teams working on PBXact-comparable platforms, FEM gateways, or SIP-based fax routing should not assume prior art or design-around positions are sufficient without formal claim mapping.
PatSnap Eureka’s FTO Search Agent can run automated claim-by-claim mapping against US8533278B2 and US8224909B2, surfacing prior art landscapes, claim scope boundaries, and design-around pathways specific to your product architecture. With Lead Case No. 2:23-cv-533 still open and potential adverse claim constructions on the horizon, running an FTO now — before any claim construction order — preserves maximum strategic flexibility for your IP and product teams.
Run a freedom-to-operate analysis on US8533278B2 to assess your product’s exposure
Run FTO in Eureka →Similar cloud PBX and fax-to-email patent cases in E.D. Texas
Explore comparable patent infringement actions asserting unified communications and fax-to-email patents before Judge Gilstrap in the Eastern District of Texas.
What this case signals for the cloud PBX and unified communications IP landscape
A fast-close, joint with-prejudice dismissal in E.D. Texas typically marks the end of a licensing negotiation — or the start of a reassessment of claim strategy.
E.D. Texas remains the preferred venue for unified communications patent enforcement
CommWorks chose Judge Gilstrap’s court — the nation’s most active patent docket — for a multi-defendant campaign targeting cloud PBX and fax-to-email functionality. Vendors operating in unified communications, hosted PBX, or fax-over-IP should treat E.D. Texas filings as a credible first-strike signal and ensure FTO clearance is current before product launch.
Joint with-prejudice dismissals in 179 days strongly suggest a licensing outcome
When both parties jointly stipulate dismissal with prejudice this early — and agree to bear their own costs — the most common explanation is a negotiated licence or covenant not to sue. No financial terms are public. Competitors facing similar assertions from CommWorks should assess whether early engagement reduces total exposure compared to full litigation.
CommWorks v Sangoma — key questions answered
The dismissal with prejudice in Case No. 2:23-cv-00534 permanently bars CommWorks from re-asserting claims against Sangoma Technologies and Sangoma US on US8533278B2 and US8224909B2. It has no binding effect on any other defendant. CommWorks retains full enforcement rights against third parties, and Lead Case No. 2:23-cv-533 remains open.
179 days is well below average for E.D. Texas patent litigation. A joint motion filed by both parties, combined with a mutual cost-bearing order, is consistent with a negotiated resolution — typically a license, covenant not to sue, or commercial settlement. No financial terms were disclosed in the public record.
CommWorks accused Sangoma’s PBXact Cloud system and its facsimile-to-email (FEM) functionality of infringing US8533278B2 and US8224909B2. These two patents cover cloud-based PBX call routing and facsimile-to-email conversion and delivery systems.
Judge Rodney Gilstrap of the Eastern District of Texas presided. Judge Gilstrap oversees more patent cases than any other federal judge in the United States. Plaintiffs frequently select E.D. Texas for its case management pace and plaintiff-receptive reputation. His court’s case management orders are typically rigorous and move cases forward on compressed schedules.
Yes. Judge Gilstrap’s order in Case No. 2:23-cv-00534 explicitly directed the Clerk to maintain Lead Case No. 2:23-cv-533 as open, indicating that CommWorks’ enforcement campaign continues against at least one additional defendant in the Eastern District of Texas.
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