Diorite Technology LLC v. Avaya LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Diorite Technology, LLC (Texas)
  • Defendant: Avaya LLC (Delaware)
  • Plaintiff’s Counsel: Farnan LLP; Russ August & Kabat
• Case Identification: 1:25-cv-01296, D. Del., 10/23/2025
• Venue Allegations: Venue is asserted based on Defendant Avaya LLC being a limited liability company formed under the laws of Delaware.
• Core Dispute: Plaintiff alleges that Defendant’s IP phone platforms, including Avaya Cloud Office and Avaya IP Office, infringe a patent related to context-aware, sequential call routing systems.
• Technical Context: The technology at issue involves advanced telecommunications systems designed to intelligently route incoming calls to a user who may have multiple communication devices and methods available.
• Key Procedural History: The complaint alleges that Plaintiff provided Defendant with notice of infringement via a letter two days prior to filing the lawsuit.

Case Timeline

Date	Event
2009-04-16	’746 Patent Priority Date
2014-06-24	’746 Patent Issue Date
2025-10-21	Notice of infringement letter sent to Defendant
2025-10-23	Complaint Filing Date

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

U.S. Patent No. 8,761,746 - Extended Cascaded Ringing

• Patent Identification: U.S. Patent No. 8,761,746, Extended Cascaded Ringing, issued June 24, 2014 (’746 Patent).

The Invention Explained

• Problem Addressed: The patent describes the difficulty of contacting a person in an era of multiple communication options (e.g., business phone, cell phone, email, instant messaging) without the expense of a personal secretary to manage and forward communications. Conventional call forwarding and "Find Me Follow Me" systems are described as inadequate for handling the contingencies of a user's changing location and availability (ʼ746 Patent, col. 3:20-44).
• The Patented Solution: The invention proposes a system that intelligently routes calls by first gathering context about the user (e.g., from a calendar server) and the caller (from caller ID), and then selecting a pre-defined "cascaded ringing program." This program defines a sequence of attempts to reach the user across different devices or communication methods, such as trying a desk phone, then a cell phone, and then sending a text message with the caller's information (ʼ746 Patent, Abstract; col. 5:36-48). The system is designed to handle situations where multiple user devices are in the same location by routing the call to only a single device to avoid redundant notifications (ʼ746 Patent, col. 10:37-44).
• Technical Importance: The technology aimed to advance call routing beyond static lists by incorporating dynamic, context-based rules to increase the probability of successfully connecting a call in a manner appropriate to the user's situation (ʼ746 Patent, col. 3:32-35).

Key Claims at a Glance

• The complaint asserts independent Claim 1 of the ’746 Patent (Compl. ¶9).
• The essential elements of Claim 1 include:
  • A system comprising at least one processor.
  • A call server configured to obtain identity information for a phone call.
  • A selection policy module comprising software configured to select a cascaded ringing program based on the caller's identity information.
  • A routing module comprising software configured to route the phone call and/or related information using the selected program.
  • A specific function wherein the selection policy module routes the call to a single communication resource at a user location when it determines multiple communication resources are present at that location.
• The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

Product Identification

• The accused instrumentalities are "Avaya IP Phone products and services using Avaya Cloud Office and Avaya IP Office platforms" (Compl. ¶9).

Functionality and Market Context

• The complaint alleges these platforms provide call management and routing functionalities. Specifically, it points to features such as "Hunt Groups" and "Telephone Redirecting Calls," which allow administrators and users to define rules for how incoming calls are distributed across multiple phones or users (Compl. ¶11). These features are central to enterprise communication systems, enabling businesses to manage call flows for departments or teams by ringing multiple extensions sequentially or simultaneously.

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

The complaint states that a claim chart comparing Claim 1 of the ’746 Patent to the Accused Instrumentalities is attached as Exhibit 2; however, that exhibit was not provided for this analysis (Compl. ¶13). The narrative infringement theory presented in the complaint is summarized below.

The complaint alleges that the Avaya Cloud Office and IP Office platforms directly infringe Claim 1 of the ’746 Patent (Compl. ¶9). The core of the allegation is that Avaya's platforms function as the claimed system for routing phone calls. The platforms allegedly act as the "call server" by receiving calls and associated caller information. The functionality that allows users to configure "Hunt Groups" and other call handling rules is alleged to constitute the claimed "selection policy module" and "cascaded ringing program." By providing these features, Avaya is alleged to make, use, sell, or offer for sale a system that practices all limitations of at least Claim 1 (Compl. ¶9, ¶11).

• Identified Points of Contention:
  • Scope Questions: A central question may be whether the configuration of a "hunt group" or a call redirection rule within the Avaya system meets the claim limitation of "selecting a cascaded ringing program...based on the identity information of the caller." The analysis may focus on whether the accused systems dynamically select a routing program in response to a specific caller's identity, or if they apply static, pre-configured rules to all incoming calls directed to a particular number.
  • Technical Questions: Claim 1 requires that the system routes a call to a "single communication resource at a user location when it is determined that multiple communication resources are located at the user location" (ʼ746 Patent, col. 15:24-32). A key technical question will be what evidence demonstrates that the accused Avaya platforms perform this specific device de-duplication function as part of their call routing logic.

V. Key Claim Terms for Construction

• The Term: "cascaded ringing program"

• Context and Importance: This term is central to the invention and appears in the asserted independent claim. Its construction will be critical to determining the scope of the patent. Practitioners may focus on this term because the infringement dispute may turn on whether Avaya's "Hunt Group" and call redirection features, which can be configured for sequential or simultaneous ringing, qualify as a "cascaded ringing program."

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification describes a program as including a "combination of serial and parallel forking" and a "sequence of parallel forks," which could be argued to cover standard hunt group configurations (ʼ746 Patent, col. 7:10-12).
  • Evidence for a Narrower Interpretation: The patent provides a detailed example of a program in an XML format that includes multiple forks with distinct timeouts, on-entrance announcements, and on-exit logging actions (ʼ746 Patent, col. 13:35-64). This detailed embodiment could be used to argue that the term requires a more complex, multi-stage logical structure than a simple sequential ringing list.

• The Term: "selecting a...program...based on the identity information of the caller"

• Context and Importance: This limitation requires a direct link between the specific caller and the routing program chosen. The dispute will likely center on the meaning of "selecting...based on."

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification suggests that information from the caller can be used "to determine how to route the phone call" (ʼ746 Patent, col. 4:35-41). This could support an interpretation where any routing rule that is triggered by an incoming call's identity (e.g., caller ID) meets the limitation.
  • Evidence for a Narrower Interpretation: The patent describes rules that apply different ringing programs to different callers or groups, such as "for calls from customers...use Ringing Program 1; for calls from my boss...use Ringing Program 2" (ʼ746 Patent, col. 7:42-47). This suggests the "selection" is an active choice between different, distinct programs depending on who is calling, rather than the application of a single, universal rule.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Avaya encourages and instructs its customers on how to use the accused platforms in an infringing manner through online user manuals and documentation for features like "Hunt group" and "incoming call handling" (Compl. ¶11).
• Willful Infringement: The complaint alleges Avaya had knowledge of the ’746 Patent "at least through the filing and service of this Complaint" and also references a notice letter dated October 21, 2025 (Compl. ¶10, ¶11). This forms the basis for an allegation of willful infringement based on knowledge of the patent.

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

This case will likely focus on the alignment between the specific, context-aware call routing system described in the ’746 Patent and the functionality of modern enterprise IP telephony platforms. The central questions for the court appear to be:

• A core issue will be one of definitional scope: can the configuration of a standard "hunt group" or call forwarding rule in the accused Avaya platforms be construed as the dynamic "selection of a cascaded ringing program based on the identity of the caller," as required by the patent claims?
• A key evidentiary question will be one of technical implementation: does the complaint provide sufficient basis to allege that the accused Avaya products perform the specific de-duplication function recited in Claim 1—actively routing a call to only a "single communication resource" when multiple are detected at the same user location?