DCT
3:25-cv-02477
Vision Sphere Labs LLC v. Draytek Corp
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Vision Sphere Labs, LLC (Texas)
- Defendant: Draytek Corporation (Taiwan)
- Plaintiff’s Counsel: Buether Joe & Counselors, LLC
- Case Identification: 3:25-cv-02477, N.D. Tex., 09/12/2025
- Venue Allegations: Plaintiff alleges venue is proper because Defendant, a non-U.S. resident, may be sued in any judicial district. Alternatively, venue is alleged based on Defendant’s U.S. distributor having a place of business in Dallas, Texas.
- Core Dispute: Plaintiff alleges that Defendant’s networking routers and related products, which feature Quality of Service (QoS) functionality, infringe two patents related to methods for managing and prioritizing data traffic in computer networks.
- Technical Context: The technology at issue is Quality of Service (QoS), a set of networking technologies used to manage data traffic to reduce packet loss, latency, and jitter, which is critical for real-time services like streaming video and voice-over-IP.
- Key Procedural History: The complaint notes that U.S. Patent No. 7,769,028 expired on September 5, 2022, limiting the period for which damages can be sought for that patent.
Case Timeline
| Date | Event |
|---|---|
| 2006-06-16 | U.S. Patent No. 7,990,860 Priority Date |
| 2006-06-21 | U.S. Patent No. 7,769,028 Priority Date |
| 2010-08-03 | U.S. Patent No. 7,769,028 Issued |
| 2011-08-02 | U.S. Patent No. 7,990,860 Issued |
| 2022-09-05 | U.S. Patent No. 7,769,028 Expired |
| 2025-09-12 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,990,860 - “Method and system for rule-based sequencing for QoS” (Issued Aug. 2, 2011)
The Invention Explained
- Problem Addressed: The patent describes shortcomings in existing Quality of Service (QoS) systems, stating they often require every node in a network to support QoS, which does not "scale well because of the large amount of state information that must be maintained" (’860 Patent, col. 4:36-50). It further notes that conventional systems cannot provide QoS based on message content at the transport layer of the network protocol stack (’860 Patent, col. 5:2-3).
- The Patented Solution: The invention proposes a system that operates "on the edge of the network" to provide QoS by prioritizing data based on user-defined rules (’860 Patent, Abstract; col. 5:19-22). The system analyzes network status, selects an operating mode based on that status, and then sequences outgoing data according to a sequencing rule associated with that mode, operating at the transport layer of the protocol stack (’860 Patent, col. 8:1-14).
- Technical Importance: The complaint alleges this approach improved the technical functioning of computer networks by providing a specific technique for prioritizing communications that helped control jitter and latency and improve data loss (’860 Patent, col. 4:27-32; Compl. ¶16).
Key Claims at a Glance
- The complaint identifies independent claim 15 as an exemplary asserted claim (Compl. ¶37).
- Essential elements of independent claim 15 (a processing device) include:
- A network analysis component configured to determine a network status and an effective link speed/proportion.
- A mode selection component to select a mode from a plurality of modes based on the network status, where each mode comprises a user-defined sequencing rule.
- A data prioritization component configured to operate at a transport layer and comprising a sequencing component to sequence data based on the selected mode's user-defined rule.
- A data metering component to shape inbound data and police outbound data.
- A data communication component to communicate the data based on its priority and the determined link speed/proportion.
- Plaintiff reserves the right to assert additional claims (Compl. ¶36).
U.S. Patent No. 7,769,028 - “Systems and methods for adaptive throughput management for event-driven message-based data” (Issued Aug. 3, 2010)
The Invention Explained
- Problem Addressed: The patent addresses the same technical problems as the ’860 Patent, highlighting that existing QoS systems are often not adaptive or configurable for different network types and cannot prioritize data based on message content at the transport layer (’028 Patent, col. 4:61-5:2).
- The Patented Solution: The invention describes a method and system for adaptively managing data throughput by prioritizing data at or near the transport layer, analyzing the network to determine its status, selecting an operational mode based on that status, and then changing the rules for assigning priority based on the selected mode (’028 Patent, Abstract; col. 6:55-62). Data is then communicated at a rate metered based on the network's status.
- Technical Importance: The complaint asserts that this technology improved computer functioning by providing a specific technique for prioritizing data communications to control jitter and latency (’028 Patent, col. 4:27-31; Compl. ¶30).
Key Claims at a Glance
- The complaint does not specify an exemplary claim, but its allegations in paragraph 31 map to independent claim 1 (Compl. ¶31).
- Essential elements of independent claim 1 (a method) include:
- Prioritizing data by assigning a priority, where the prioritization occurs at or at the top of the transport layer.
- Analyzing a network to determine a status.
- Selecting a mode based on the network status.
- Changing rules for assigning priority to the data based upon the selected mode.
- Communicating the data based on its priority and the network status, where the communication occurs at a transmission rate metered based on the network status.
- Plaintiff reserves the right to assert additional claims (Compl. ¶46).
III. The Accused Instrumentality
Product Identification
The accused instrumentalities for the ’860 Patent are Draytek routers, switches, and platforms that operate with the “Traffic Shaping” feature (the "Accused '860 Products") (Compl. ¶36). For the ’028 Patent, the accused instrumentalities are Draytek products operating with the “QoS Configuration” features (the "Accused '028 Products") (Compl. ¶46).
Functionality and Market Context
The complaint alleges that the "Traffic Shaping" and "QoS Configuration" features in Defendant's products provide Quality of Service functionality, which is used to manage and prioritize network traffic (Compl. ¶36, ¶46). The complaint alleges that Defendant’s U.S. operations are managed by a "Texas-based master distributor" responsible for distribution in the North American market (Compl. ¶7).
IV. Analysis of Infringement Allegations
The complaint references preliminary claim charts in an exhibit that was not provided. The analysis below is based on the narrative breakdown of claim elements provided in the body of the complaint.
'860 Patent Infringement Allegations
| Claim Element (from Independent Claim 15) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a network analysis component configured to determine a network status from a plurality of network statuses based on analysis of network measurements, and determine at least one of an effective link speed and a link proportion for at least one link | The complaint alleges the accused products contain a network analysis component that determines network status and effective link speed/proportion. | ¶17 | col. 14:10-18 |
| a mode selection component configured to select a mode from a plurality of modes that corresponds with at least one of the plurality of network statuses based on the determined network status, where each of the plurality of modes comprises a user defined sequencing rule | The complaint alleges the accused products contain a mode selection component that selects a mode based on network status, where modes contain user-defined sequencing rules. | ¶17 | col. 14:19-24 |
| a data prioritization component configured to operate at a transport layer of a protocol stack and prioritize the data by assigning a priority to the data, where the prioritization component includes a sequencing component configured to sequence the data based at least in part on the user defined sequencing rule of the selected mode | The complaint alleges the accused products contain a data prioritization component operating at the transport layer that sequences data based on the user-defined sequencing rule of the selected mode. | ¶17 | col. 14:25-31 |
| a data metering component configured to meter inbound data by shaping the inbound data ... and meter outbound data by policing the outbound data | The complaint alleges the accused products contain a data metering component that shapes inbound data and polices outbound data. | ¶17 | col. 14:32-37 |
| a data communication component configured to communicate the data based at least in part on the priority of the data, the effective link speed, and/or the link proportion | The complaint alleges the accused products contain a data communication component that communicates data based on priority, effective link speed, and/or link proportion. | ¶17 | col. 14:38-42 |
'028 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| prioritizing data by assigning a priority to the data, where the prioritization occurs either as part of and/or at the top of the transport layer | The complaint alleges the accused products prioritize data by assigning a priority at or near the top of the transport layer. | ¶31 | col. 23:12-17 |
| analyze a network to determine a status of the network | The complaint alleges the accused products analyze a network to determine its status. | ¶31 | col. 23:20-21 |
| select a mode based on the status of the network | The complaint alleges the accused products select a mode based on the network status. | ¶31 | col. 23:22-23 |
| change rules for assigning priority to the data based on the mode | The complaint alleges the accused products change rules for assigning priority to data based on the selected mode. | ¶31 | col. 23:24-25 |
| communicate the data based at least in part on the priority of the data and the status of the network, where the data is communicated at a transmission rate metered based at least in part on the status of the network | The complaint alleges the accused products communicate data based on priority and network status, at a transmission rate that is metered based on network status. | ¶31 | col. 23:26-31 |
No probative visual evidence provided in complaint.
- Identified Points of Contention:
- Scope Questions: The case may turn on whether Defendant’s "Traffic Shaping" and "QoS Configuration" features, as implemented, meet the specific architectural requirements of the claims. For example, a question for the court will be whether the accused prioritization functions operate "at a transport layer of a protocol stack" (’860 Patent, Claim 15) or "at the top of the transport layer" (’028 Patent, Claim 1) as claimed, or if they operate at a different layer (e.g., the network or application layer) in a way that falls outside the claim scope.
- Technical Questions: A factual question will be what evidence demonstrates that the accused products "select a mode from a plurality of modes" and "change rules for assigning priority" based on that mode in response to a dynamically "determined network status" (’860 Patent, Claim 15; ’028 Patent, Claim 1), as opposed to using a static, pre-configured set of QoS rules.
V. Key Claim Terms for Construction
For the '860 Patent:
- The Term: "user defined sequencing rule" (Claim 15)
- Context and Importance: This term appears central to the patent's claimed point of novelty over prior art QoS systems. The definition will be critical to determine whether the accused "Traffic Shaping" feature, which may allow user configuration, implements the specific type of "sequencing rule" contemplated by the patent. Practitioners may focus on this term because the degree of user control and the nature of the "rule" (e.g., is it a simple priority queue or a more complex algorithm like round-robin) will be a key infringement question.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification provides examples of sequencing rules, including "starvation, round robin, relative frequency, etc.," suggesting the term is not limited to a single algorithm but encompasses a category of rules for ordering data streams (’860 Patent, col. 8:7-9).
- Evidence for a Narrower Interpretation: The detailed description ties the sequencing rule to a "sequencing algorithm that controls samples of queue fronts," which could be argued to require a specific mechanism for sampling from different data queues, rather than any general user-configurable priority setting (’860 Patent, col. 8:46-49).
For the '028 Patent:
- The Term: "prioritization occurs either as part of and/or at the top of the transport layer" (Claim 1)
- Context and Importance: The location of the prioritization function within the OSI protocol stack is a critical limitation distinguishing the invention from network-layer QoS systems. Infringement will depend on a precise factual determination of where in the protocol stack the accused "QoS Configuration" feature operates.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The phrase "as part of and/or at the top of" suggests some flexibility. The specification states the system "operates as part of and/or at the top of the transport layer" and may "give precedence to higher priority data ... passed to the transport layer," which could support a construction that includes operations closely associated with, but not strictly within, the transport layer itself (’028 Patent, col. 6:58-61).
- Evidence for a Narrower Interpretation: The specification also provides a specific example of implementation: "when an application opens a socket, the system 150 may filter data at this point in the protocol stack," tying the operation directly to the transport layer's socket interface (’028 Patent, col. 8:57-60). This could support an argument that the prioritization must occur at this specific programmatic point.
VI. Other Allegations
- Indirect Infringement: The complaint alleges both induced and contributory infringement for both patents. It asserts that Defendant provides the accused products and software components knowing they are "specially made or adapted for use in an infringing manner" and are "not staple articles with substantial non-infringing uses" (Compl. ¶38-40, ¶48-49).
- Willful Infringement: For both patents, the complaint makes placeholder allegations of willfulness, stating that evidentiary support for Defendant's knowledge "will likely have evidentiary support after a reasonable opportunity for discovery" (Compl. ¶41, ¶50).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of architectural location: Does the accused "Traffic Shaping" and "QoS Configuration" functionality operate "at a transport layer" as the patents claim, or does it primarily function at the network layer (Layer 3) or another part of the protocol stack, potentially placing it outside the scope of the claims?
- A key evidentiary question will be one of dynamic adaptability: What evidence will show that the accused products dynamically "determine a network status" and "select a mode" or "change rules" in response, as required by the claims, rather than simply applying a static, user-configured set of priority rules that are not responsive to real-time network conditions?
- A third question will be one of definitional scope: Can the configuration options available to a user in the accused products be properly characterized as the "user defined sequencing rule" claimed in the ’860 Patent, or is there a technical mismatch between the claimed rule-based sequencing and the functionality offered by Defendant?