Diorite Technology LLC v. Cisco Systems Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Diorite Technology, LLC (Texas)
  • Defendant: Cisco Systems, Inc. (Delaware)
  • Plaintiff’s Counsel: Russ August & Kabat
• Case Identification: 2:25-cv-00591, E.D. Tex., 05/28/2025
• Venue Allegations: Plaintiff alleges venue is proper because Defendant has committed acts of infringement and maintains a regular and established place of business in the Eastern District of Texas, specifically citing office locations in Richardson, Texas.
• Core Dispute: Plaintiff alleges that Defendant’s Cisco Desk and Cisco Broadworks telecommunications products infringe three patents related to enhanced automatic callback systems, conference call user interfaces, and mass audio notification systems.
• Technical Context: The patents address technologies in the enterprise communication and teleconferencing sector, focusing on improving user experience and system intelligence in voice and video collaboration environments.
• Key Procedural History: The complaint does not reference any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history concerning the patents-in-suit.

Case Timeline

Date	Event
2007-06-21	U.S. Patent No. 8,189,759 Priority Date
2010-04-30	U.S. Patent No. 9,344,820 Priority Date
2011-06-21	U.S. Patent No. 9,007,421 Priority Date
2012-05-29	U.S. Patent No. 8,189,759 Issues
2015-04-14	U.S. Patent No. 9,007,421 Issues
2016-05-17	U.S. Patent No. 9,344,820 Issues
2025-05-28	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 8,189,759 - “System and Method for Automatic Call Back Using Availability Information,” issued May 29, 2012

The Invention Explained

• Problem Addressed: The patent addresses the limitations of traditional "Automatic Callback" (ACB) features in phone systems. These features trigger a callback when a previously busy or unanswered line becomes free (goes "on hook"), but this is a "very coarse" indication of availability and does not account for whether the user is actually free to take a call, a potentially leading to disruptive callbacks or long delays for urgent matters (’759 Patent, col. 1:11-34).
• The Patented Solution: The invention enhances the ACB feature by integrating it with modern "presence services," such as those used in instant messaging applications. Instead of relying only on the on-hook/off-hook status of a phone, the system determines a user's availability by checking their presence status (e.g., "In a Meeting," "Busy") and evaluating whether that status is compatible with receiving an incoming call based on a predefined list. The callback is initiated only if the user's presence status is deemed compatible (’759 Patent, Abstract; col. 4:25-42).
• Technical Importance: The technology represents an effort to bridge legacy PBX functionalities with modern, context-aware unified communications by making automated telephony actions more intelligent and less intrusive. (’759 Patent, col. 2:55-65).

Key Claims at a Glance

• The complaint asserts independent claim 1 (Compl. ¶10).
• Claim 1 of the ’759 Patent recites a method for controlling a callback, comprising the key steps of:
  • Determining a call attempt from a first device to a second device failed.
  • Setting an automatic call back feature in a call controller.
  • Monitoring a status of the called party at a presence server and receiving status messages.
  • Determining an availability status by comparing the received status messages to a list of compatible availability states.
  • Further determining availability by evaluating the compatibility of a call feature (e.g., DO NOT DISTURB) selected by the called party.
  • Initiating the callback only if the availability status is compatible with both the presence state and the selected call feature.
• The complaint reserves the right to assert additional claims (Compl. ¶13).

U.S. Patent No. 9,007,421 - “Conference Call User Interface and Methods Thereof,” issued April 14, 2015

The Invention Explained

• Problem Addressed: The patent identifies that user interfaces for setting up and managing multi-party conference calls are often limited and not intuitive, particularly for infrequent users dealing with common-use devices in meeting rooms (’421 Patent, col. 1:21-34).
• The Patented Solution: The invention proposes a graphical user interface (GUI) for a collaboration appliance that simplifies conference management. It displays "graphics representing a plurality of characters," or avatars, arranged around a virtual conference table. Users can initiate calls and add participants by interacting with these avatars, for example, by touching a phone icon displayed on an avatar's chest. Once a party is connected, a "participant panel" appears, providing intuitive options to manage that specific participant, such as "Escalate to Video" or "End Call." (’421 Patent, Abstract; col. 4:56-col. 5:11; col. 6:55-col. 7:4).
• Technical Importance: The invention aims to lower the barrier to using advanced teleconferencing features by replacing button-based interfaces with a more intuitive, visual metaphor of a physical meeting room. (’421 Patent, col. 2:51-54).

Key Claims at a Glance

• The complaint asserts independent claim 1 (Compl. ¶18).
• Claim 1 of the ’421 Patent recites an apparatus with a touch display and processor configured to:
  • Display graphics representing a plurality of characters and the apparatus itself on a user interface.
  • Display phone icons on the characters and the apparatus.
  • Connect with a device when a phone icon is actuated.
  • Associate the connected device with one of the characters.
  • Display the character with an identifier of the device.
  • Wherein connecting comprises displaying a "participant panel" associated with the character, the panel having an "End Call" option, a "Hold" option, an "Escalate to Video" option, and a "De-escalate from Video" option.
• The complaint reserves the right to assert additional claims (Compl. ¶21).

Multi-Patent Capsule

U.S. Patent No. 9,344,820 - “Method, Apparatus, and System for Mass Audio Notification Field,” issued May 17, 2016

• Technology Synopsis: The patent describes a mass notification system using IP-networked speakers. A central server sends audio and control commands over a network to individual or grouped speakers, addressing the scalability and configuration limits of traditional, self-contained analogue PA systems. (’820 Patent, Abstract; col. 1:12-34).
• Asserted Claims: The complaint asserts independent claim 1 (Compl. ¶26).
• Accused Features: The complaint alleges that Cisco Desk products infringe the ’820 Patent (Compl. ¶26).

III. The Accused Instrumentality

Product Identification

The complaint identifies the "Accused Instrumentalities" as "Cisco Desk and Cisco Broadworks products," including the "Desk Phone 9800 Series" (Compl. ¶4, 10, 18).

Functionality and Market Context

The complaint alleges that these products provide advanced telecommunications and collaboration functionalities. Specifically, it alleges the Cisco Broadworks products provide an automatic callback feature that uses availability information, and that the Cisco Desk products provide a graphical user interface for managing conference calls (Compl. ¶10, 18). The complaint alleges that Cisco provides user manuals and online instructions for these features, suggesting they are user-facing functionalities central to the products' operation (Compl. ¶11, 19). The complaint does not provide further technical detail on the operation of the accused products.

IV. Analysis of Infringement Allegations

The complaint references claim chart exhibits that were not provided. The following summarizes the narrative infringement theories presented in the complaint.

’759 Patent Infringement Allegations

The complaint alleges that Cisco’s Broadworks products, including the Desk Phone 9800 Series, directly infringe at least Claim 1 (Compl. ¶10). The infringement theory is that these products implement an automatic callback feature that, like the claimed invention, determines a called party’s availability using presence information beyond a simple on-hook/off-hook status, and initiates a callback based on that enhanced availability information. The complaint states a claim chart is attached as Exhibit 2, but this exhibit was not available for analysis (Compl. ¶13).

’421 Patent Infringement Allegations

The complaint alleges that the Cisco Desk products directly infringe at least Claim 1 by providing a conference call user interface (Compl. ¶18). The infringement theory is that this interface displays graphical representations of participants (the claimed "characters") and allows a user to manage the conference by interacting with these graphics. This interaction allegedly includes bringing up a control panel (the claimed "participant panel") with options for ending a call, placing it on hold, or escalating to video, thereby mapping to the specific elements of Claim 1. The complaint states a claim chart is attached as Exhibit 4, but this exhibit was not available for analysis (Compl. ¶21).

No probative visual evidence provided in complaint.

Identified Points of Contention

• Scope Questions (’759 Patent): A central question may be whether the "availability information" allegedly used by the accused products meets the specific requirements of Claim 1. The claim requires not only checking a presence status (e.g., "Busy") but also "evaluating compatibility of a call feature selected by said called party" (e.g., "DO NOT DISTURB"). The case may turn on whether the accused system performs this two-part evaluation or a simpler form of presence check.
• Technical Questions (’421 Patent): An issue for the court will be whether the graphical elements in the accused Cisco Desk UI constitute "graphics representing a plurality of characters" as that term is used in the patent. Furthermore, the infringement analysis will depend on whether actuating these graphics displays a "participant panel" containing the exact set of options recited in Claim 1, including "End Call," "Hold," "Escalate to Video," and "De-escalate from Video" options.

V. Key Claim Terms for Construction

’759 Patent, Claim 1

• The Term: "evaluating compatibility of said availability status by comparing said received status messages to a list of compatible availability states"
• Context and Importance: This phrase defines the core logic of the invention, distinguishing it from merely reporting a presence status. Practitioners may focus on this term because infringement will depend on whether the accused product performs this specific comparison against a "list," rather than a more general availability check.
• Intrinsic Evidence for a Broader Interpretation: The patent states the list is "maintained within PBX 140, or alternatively in memory 185" (’759 Patent, col. 4:35-37), suggesting flexibility in how the list is implemented, which could support a broader reading of any rules-based evaluation.
• Intrinsic Evidence for a Narrower Interpretation: The claim separately recites evaluating selected call features (like "DO NOT DISTURB"). A defendant may argue that the "evaluating compatibility" step is therefore limited strictly to presence status messages (e.g., "In the Office," "Busy") and does not encompass the separate evaluation of phone features, requiring a plaintiff to prove both distinct steps occur.

’421 Patent, Claim 1

• The Term: "graphics representing a plurality of characters"
• Context and Importance: The definition of "character" is fundamental to whether the accused interface infringes. If the UI elements in the Cisco product do not meet this definition, the claim is not infringed.
• Intrinsic Evidence for a Broader Interpretation: The specification states that "The avatars 306 can be any character or object and is not limited to those shown" (’421 Patent, col. 4:65-67), which could support construing the term to cover a wide range of graphical representations, not just human-like figures.
• Intrinsic Evidence for a Narrower Interpretation: The patent’s figures and primary embodiment consistently depict avatars as having a "shape or outline of a human form" (’421 Patent, col. 4:62-64; Fig. 3). A defendant could argue that the term should be construed in light of these consistent examples to require a representation with some anthropomorphic features, rather than any abstract shape.

VI. Other Allegations

Indirect Infringement

The complaint alleges both induced and contributory infringement for all three patents-in-suit. The inducement allegation is based on Cisco allegedly encouraging infringement by providing customers with "user manuals and online instruction materials" that instruct them to use the accused products in an infringing manner (Compl. ¶11, 19, 27). The contributory infringement allegation is based on the accused products being especially made or adapted for infringing the patents and not being staple articles of commerce (Compl. ¶12, 20, 28).

Willful Infringement

The complaint alleges that Cisco has knowledge of the patents and infringement "Through at least the filing and service of this Complaint" (Compl. ¶11, 19, 27). This phrasing forms a basis for post-suit willfulness but does not allege that Cisco had knowledge of the patents prior to the lawsuit being filed.

VII. Analyst’s Conclusion: Key Questions for the Case

• A core issue will be one of functional equivalence: Does Cisco’s automatic callback feature perform the specific, multi-step evaluation of both presence status and selected call features as required by Claim 1 of the ’759 patent, or does it utilize a technically distinct and simpler availability check?
• The case will also turn on a question of definitional scope: Do the graphical elements in the accused Cisco conferencing UI qualify as "characters" as understood in the context of the ’421 patent, and does interaction with them present a "participant panel" with the specific, exhaustive list of four control options recited in Claim 1?
• Finally, a key evidentiary question for damages will be notice and willfulness: Can the plaintiff produce evidence of pre-suit knowledge to support its claim for enhanced damages, or will the willfulness inquiry be limited to Cisco's conduct after the complaint was filed?