DCT
2:21-cv-00481
Estech Systems IP LLC v. Primoris Design Construction Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Estech Systems IP, LLC (Texas)
- Defendant: Primoris Services Corporation (Delaware); Primoris Design & Construction, Inc. (Delaware)
- Plaintiff’s Counsel: WILLIAMS SIMONS & LANDIS PLLC
- Case Identification: 2:21-cv-00481, E.D. Tex., 12/31/2021
- Venue Allegations: Venue is alleged to be proper as Defendants maintain at least one regular and established place of business within the Eastern District of Texas.
- Core Dispute: Plaintiff alleges that Defendants' Voice over IP (VoIP) telephone and networking systems infringe four patents related to VoIP phone directories, quality of service, remote voicemail access, and caller ID-based dialing.
- Technical Context: The dispute concerns Voice over IP (VoIP) telephony systems, a technology that transmits voice communications over data networks, offering cost savings and feature integration advantages over traditional telephony.
- Key Procedural History: U.S. Patent No. 8,391,298 and U.S. Patent No. 6,067,349, two of the four patents-in-suit, were subject to Inter Partes Review (IPR) proceedings subsequent to the complaint's filing. According to attached certificates, these IPRs resulted in the cancellation of all asserted independent claims for both patents, which may significantly impact the viability of the infringement contentions for those patents.
Case Timeline
| Date | Event |
|---|---|
| 1997-12-31 | Priority Date for U.S. Patent No. 6,067,349 |
| 2000-05-23 | Issue Date for U.S. Patent No. 6,067,349 |
| 2001-02-01 | Priority Date for U.S. Patent No. 8,391,298 |
| 2001-02-01 | Priority Date for U.S. Patent No. 7,068,684 |
| 2001-02-01 | Priority Date for U.S. Patent No. 7,123,699 |
| 2006-06-27 | Issue Date for U.S. Patent No. 7,068,684 |
| 2006-10-17 | Issue Date for U.S. Patent No. 7,123,699 |
| 2013-03-05 | Issue Date for U.S. Patent No. 8,391,298 |
| 2021-12-31 | Complaint Filing Date |
| 2023-06-30 | IPR Certificate Issued for U.S. Patent No. 6,067,349 |
| 2025-02-12 | IPR Certificate Issued for U.S. Patent No. 8,391,298 |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,391,298 - "Phone Directory in a Voice Over IP Telephone System," issued March 5, 2013
The Invention Explained
- Problem Addressed: The patent describes enterprise communication systems distributed across multiple geographic locations using local and wide area networks (LANs and WANs), but does not explicitly state a problem. The invention implies a need for users in one location to easily access and dial extensions in other, separate locations without needing a printed directory or operator assistance (’298 Patent, Abstract; col. 10:1-12).
- The Patented Solution: The patent discloses an information handling system with a specific architecture comprising at least three LANs connected by a WAN. A server on a second LAN stores a list of telecommunications extensions. A user at a device on the first LAN can view that list of extensions stored on the second LAN, and can also select to view a separate list of extensions located on a third LAN, enabling seamless directory access across the distributed network (’298 Patent, col. 16:1-19).
- Technical Importance: The invention describes a method for centralizing or federating user directories in a multi-site VoIP environment, which simplifies administration and improves user experience in geographically dispersed organizations (’298 Patent, col. 9:55-67).
Key Claims at a Glance
- The complaint asserts at least independent Claim 1 (Compl. ¶31). The patent’s attached Inter Partes Review certificate indicates that claims 1-12 have been cancelled.
- Claim 1 requires:
- An information handling system with a first LAN, a second LAN, a third LAN, and a WAN coupling the first and second LANs.
- A first telecommunications device on the first LAN with circuitry to observe a list of extensions.
- A plurality of telecommunications extensions on the second LAN, with the list of these extensions stored on a server in the second LAN.
- Circuitry on the first LAN for automatically calling a selected extension from the list.
- A plurality of extensions on the third LAN, and circuitry enabling a user to select between observing the list from the second LAN or a list from the third LAN.
U.S. Patent No. 7,068,684 - "Quality of Service in a Voice Over IP Telephone System," issued June 27, 2006
The Invention Explained
- Problem Addressed: On shared data networks like Ethernet, large data transfers (e.g., a print job) can consume significant bandwidth and cause delays, which degrades the quality of real-time applications like VoIP calls that cannot tolerate such latency (’684 Patent, col. 1:50-68). This is often referred to as a Quality of Service (QoS) problem.
- The Patented Solution: The patent describes a method and system where an IP telephone is physically connected between a workstation (e.g., a PC) and the network hub. The IP telephone monitors data traffic and, to prioritize voice quality, can "throttle" the data coming from the workstation. This throttling is achieved by reducing a future amount of data transfer from the workstation if the current amount exceeds a set threshold, thereby ensuring sufficient bandwidth for the audio information of a call (’684 Patent, col. 20:13-20). The specification describes a specific embodiment of throttling using a "jabber" process to create intentional network collisions (’684 Patent, col. 13:46-51).
- Technical Importance: This approach provides a mechanism to enforce QoS for voice traffic at the network edge, directly at the user's device, without requiring complex configurations in the central network switches or routers (’684 Patent, col. 2:25-30).
Key Claims at a Glance
- The complaint asserts at least independent Claim 36 (Compl. ¶52).
- Claim 36 requires a method comprising the steps of:
- Transferring data from a workstation to a telephone, where the data is addressed to a data server.
- Communicating audio information between the telephone and a multimedia server.
- Sufficiently throttling the data from the workstation to the telephone to increase the transfer rate of the audio information.
- Wherein the throttling step includes reducing a future amount of data transfer from the workstation if the amount of data exceeds a predetermined threshold.
U.S. Patent No. 7,123,699 - "Voice Mail in a Voice Over IP Telephone System," issued October 17, 2006
- Technology Synopsis: The patent addresses accessing voicemail across a distributed VoIP network. The invention describes a system where a voice message is stored in a mailbox on a first LAN, and a user at a telecommunications device on a second LAN receives a "sensory indication" (e.g., a message waiting light) that a message is waiting. The user can then access and listen to the message by establishing a connection from the second LAN to the first LAN over a WAN. (Compl. ¶65; ’699 Patent, Abstract).
- Asserted Claims: At least Claim 1 (Compl. ¶73).
- Accused Features: The complaint alleges that Defendants' VoIP systems include servers that store voicemail messages on a first LAN and telephony devices on a second LAN that provide an indication of and allow users to access those messages across a WAN (Compl. ¶¶70-71).
U.S. Patent No. 6,067,349 - "Dialing Using Caller ID," issued May 23, 2000
- Technology Synopsis: The patent describes a telephone system that enhances voicemail functionality using caller ID. When a caller leaves a voicemail, the system stores the caller's ID information (e.g., phone number) in association with the message. This allows the recipient to automatically initiate a call back to the person who left the message, for instance by pressing a single redial key while listening to the voicemail. (Compl. ¶86; ’349 Patent, Abstract). The patent was subject to an Inter Partes Review that resulted in the cancellation of the asserted claim.
- Asserted Claims: At least Claim 1 (Compl. ¶91).
- Accused Features: Defendants' voicemail systems are accused of associating caller ID information with a voicemail message to permit a user to automatically call back the caller while listening to the message (Compl. ¶86).
III. The Accused Instrumentality
Product Identification
- The complaint identifies the accused products generally as "VoIP telephone systems and networking equipment utilized by Defendants" (Compl. ¶25), and refers to them collectively as the "Accused Instrumentalities." No specific product names are provided.
Functionality and Market Context
- The complaint alleges the Accused Instrumentalities provide VoIP-based voice calling and data-networking services (Compl. ¶26). Their functionality is described as including the use of multiple LANs coupled with a WAN (Compl. ¶27), VoIP telephony devices with associated extensions (Compl. ¶28), and servers that store telecommunications extensions (Compl. ¶30). They are also alleged to provide quality of service by throttling data sent from workstations (Compl. ¶51) and to offer features for accessing voicemail across a WAN (Compl. ¶¶70-71). The complaint does not provide detail regarding the products' specific commercial importance or market position.
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint.
’298 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a first LAN; a second LAN; a WAN coupling the first and second LANs; a third LAN | The Accused Instrumentalities allegedly use a network architecture of first, second, and third LANs coupled with a WAN (Compl. ¶27). | ¶27 | col. 4:58-62 |
| a plurality of telecommunications extensions coupled to the second LAN | The Accused Instrumentalities are alleged to include VoIP telephony devices with associated telecommunications extensions, with these extensions being coupled to the second and third LANs (Compl. ¶28). | ¶28 | col. 16:10-11 |
| the first LAN including first circuitry for enabling a user of the first telecommunications device to observe a list of the plurality of telecommunications extensions... stored in a server in the second LAN | The telephony devices allegedly include circuitry that enables users to observe a list of extensions (Compl. ¶29). This list is allegedly stored on servers in the second LAN and accessed across the WAN (Compl. ¶30). | ¶29-30 | col. 16:6-9 |
| the first LAN including second circuitry for automatically calling one of the plurality of telecommunications extensions in response to the user selecting one... from the observed list | The telephony devices allegedly include circuitry to automatically call an extension when a user selects it from the list (Compl. ¶29). | ¶29 | col. 16:12-16 |
| a plurality of telecommunications extensions coupled to the third LAN, the first LAN including circuitry for enabling the user to select between observing the list... coupled to the second LAN or... the third LAN | The telephony devices allegedly include circuitry that enables a user to select between observing the list of extensions on the second LAN or the list on the third LAN (Compl. ¶29). | ¶29 | col. 16:17-19 |
- Identified Points of Contention:
- Legal Question: The primary issue is legal rather than technical: given that the Inter Partes Review certificate indicates Claim 1 has been cancelled, on what basis can the infringement allegation proceed?
- Scope Question: A secondary question is whether the defendants' network architecture, once detailed in discovery, maps onto the specific "first, second, and third LAN" structure required by the claim, or if it uses a different topology (e.g., a hub-and-spoke or cloud-based model) that may not meet this limitation.
’684 Patent Infringement Allegations
| Claim Element (from Independent Claim 36) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| transferring data from the workstation to the telephone, wherein the data sent from the workstation is addressed for transmission to the data server | The Accused Instrumentalities are alleged to include workstations that send and receive data from data servers, with the data being transferred through VoIP telephony devices (Compl. ¶50). | ¶50 | col. 20:13-15 |
| communicating audio information between the telephone and the multimedia server | The Accused Instrumentalities allegedly include VoIP servers, and audio information for VoIP calls is communicated between telephony devices and these servers (Compl. ¶49). | ¶49 | col. 20:16-17 |
| sufficiently throttling the data sent from the workstation to the telephone to increase a rate of transfer of the audio information... | The complaint alleges that the Accused Instrumentalities "sufficiently throttle data sent from workstations to VoIP telephony devices to increase a rate of transfer of audio information" during a call (Compl. ¶51). | ¶51 | col. 20:18-20 |
| wherein the throttling step further comprises the step of reducing a future amount of data from being transferred from the workstation if the amount of data exceeds a predetermined threshold | The complaint alleges that the "data throttling comprises reducing a future amount of data from being transferred from the workstation if the amount of data exceeds a predetermined threshold" (Compl. ¶51). | ¶51 | col. 20:18-20 |
- Identified Points of Contention:
- Technical Question: What evidence does the complaint provide that the accused product’s general QoS functionality performs the specific method of "reducing a future amount of data... if the amount of data exceeds a predetermined threshold"? The allegation in the complaint (¶51) directly mirrors the claim language without offering supporting factual detail on the technical implementation.
- Scope Question: A key dispute will likely focus on whether the term "throttling" should be construed narrowly to mean the specific "jabbering" and "duty cycle" technique described in the patent's specification, or broadly to cover any form of data traffic prioritization that benefits voice calls.
V. Key Claim Terms for Construction
For the ’684 Patent:
- The Term: "throttling"
- Context and Importance: This term is the central inventive concept of Claim 36. Its definition will determine whether any generic QoS system infringes, or if infringement requires the specific, and arguably unusual, technical implementation described in the patent. Practitioners may focus on this term because the complaint's allegations are conclusory and lack technical specifics.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim itself defines throttling as an action that "increase[s] a rate of transfer of the audio information" and includes "reducing a future amount of data" transfer based on a threshold (col. 20:18-20). A party could argue this functional language defines the term without being limited to a specific structure.
- Evidence for a Narrower Interpretation: The specification describes the throttling mechanism in great detail as a process of "jabbering," or intentionally flooding a network segment with collisions to freeze data transmission from the workstation, performed with a specific duty cycle (col. 13:46-60). A party could argue this is the only disclosed method of "throttling" and the claims should be limited to this embodiment.
For the ’298 Patent:
- The Term: "a first LAN; a second LAN;... a third LAN"
- Context and Importance: The claim requires a specific three-LAN architecture. The construction of this term is critical because modern VoIP systems may use cloud-based or different network topologies that do not map cleanly onto three distinct LANs. The viability of the claim, assuming it were not cancelled, would depend on whether a defendant's architecture meets this limitation.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party might argue that "LAN" should be interpreted functionally to mean logically separate network segments, regardless of the physical hardware, allowing the claim to read on virtual LANs (VLANs) or cloud-based subnets.
- Evidence for a Narrower Interpretation: The patent’s figures and description consistently depict distinct, physically separate systems (e.g., "Dallas 301," "Detroit 302") connected over a WAN, suggesting that "LAN" refers to a traditional, geographically-defined local area network (’298 Patent, Fig. 3).
VI. Other Allegations
- Indirect Infringement: For all asserted patents, the complaint alleges both induced and contributory infringement. The allegations state that Defendants induced infringement by "advising or directing customers... to make or use the Accused Instrumentalities in an infringing manner" and distributing instructions (e.g., Compl. ¶¶34, 55). Contributory infringement is alleged on the basis that the accused products have "special features" with no substantial non-infringing use (e.g., Compl. ¶¶35, 56).
- Willful Infringement: Willfulness is alleged for all patents. The allegations are based on knowledge "at least as of the date when they were notified of the filing of this action" and a theory of willful blindness, asserting that Defendants have a "policy or practice of not reviewing the patents of others" (e.g., Compl. ¶¶36-39, 57-60).
VII. Analyst’s Conclusion: Key Questions for the Case
- A threshold legal question for two of the four patents ('298 and '349) will be one of case viability: can the infringement causes of action proceed on claims that were cancelled in Inter Partes Review proceedings after the complaint was filed?
- A central evidentiary question will be one of technical specificity: can Plaintiff produce evidence that Defendants' generally-described VoIP systems practice the specific, multi-part limitations of the asserted claims, particularly the three-LAN directory architecture of the '298 patent and the predictive "data throttling" method of the '684 patent?
- The dispute may turn on a question of definitional scope: for the '684 patent, can the term "throttling," which the complaint uses conclusorily, be construed to cover generic QoS prioritization, or will it be limited to the specific "jabbering" embodiment described in the specification, creating a potential mismatch with the accused functionality?