Winterspring Digital LLC v. Extreme Networks Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Winterspring Digital LLC (Texas)
  • Defendant: Extreme Networks, Inc. (Delaware)
  • Plaintiff’s Counsel: Fabricant LLP
• Case Identification: 2:23-cv-00374, E.D. Tex., 08/21/2023
• Venue Allegations: Plaintiff alleges venue is proper because Defendant maintains a regular and established place of business within the Eastern District of Texas and has transacted business and sold the accused products in the district.
• Core Dispute: Plaintiff alleges that Defendant’s network switches and related network management software infringe three patents related to high-speed data transmission, network administration, and packet tagging.
• Technical Context: The technology at issue resides in the field of high-speed computer networking, addressing methods for efficiently routing, managing, and processing data traffic in complex enterprise environments.
• Key Procedural History: The complaint does not allege any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history related to the patents-in-suit.

Case Timeline

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

U.S. Patent No. 7,164,692 - "Apparatus and Method for Transmitting 10 Gigabit Ethernet LAN Signals Over a Transport System," Issued Jan. 16, 2007

• The Invention Explained:
  • Problem Addressed: The patent identifies the technical and economic inefficiencies of connecting high-speed Local Area Networks (LANs) over long-distance Wide Area Network (WAN) infrastructure (Compl. ¶12; ’692 Patent, col. 2:4-25). Specifically, it notes that encapsulating native Ethernet frames into legacy transport formats like SONET adds unnecessary complexity and cost (’692 Patent, col. 3:1-10).
  • The Patented Solution: The invention proposes a transceiver that processes a 10 Gigabit Ethernet (10GE) LAN signal in its native format for transmission over a transport system. The system receives a client 10GE LAN signal, converts it to an internal electrical signal, re-clocks it to ensure signal integrity, and then re-modulates it for transmission, all without converting the data to a non-native format like SONET (’692 Patent, Abstract; col. 5:20-33).
  • Technical Importance: This approach was designed to simplify the extension of high-speed Ethernet networks over long distances, potentially reducing equipment costs and overhead associated with traditional WAN technologies (’692 Patent, col. 2:55-59).
• Key Claims at a Glance:
  • The complaint asserts at least independent method claim 10 (Compl. ¶19).
  • The essential elements of Claim 10 include:
    • Receiving a 10GE LAN client signal from a transport system.
    • Converting the signal to an intermediate form.
    • Recovering clock data and a data stream from the intermediate signal.
    • Reconverting the intermediate signal back to a 10GE LAN client signal.
    • Transferring the signal to a client system.
    • Monitoring the intermediate form with a 10GE LAN media access controller.
  • The complaint alleges infringement of "one or more claims," preserving the right to assert others (Compl. ¶18).

U.S. Patent No. 8,032,646 - "Administering a Communication Network," Issued Oct. 4, 2011

• The Invention Explained:
  • Problem Addressed: The patent describes a deficiency in existing network management tools, which were focused on fault detection and provisioning individual routers but lacked the capability to administer entire paths of routers for specific applications like Voice over IP (VoIP) in a holistic manner (’646 Patent, col. 1:36-62).
  • The Patented Solution: The invention discloses a system with a Graphical User Interface (GUI) that enables a network administrator to manage network traffic more effectively. The GUI displays a map of network nodes, including "media aggregation managers" (edge nodes), and graphically depicts multiple potential data paths between them. An administrator can then select a specific path and initiate a "path-level configuration" of all routers on that path to handle traffic according to a desired schedule or quality of service requirement (’646 Patent, Abstract; col. 8:37-50).
  • Technical Importance: The technology aimed to simplify the complex task of provisioning networks for quality-of-service-sensitive applications by allowing administrators to configure and analyze entire data paths at once, rather than device by device (’646 Patent, col. 3:5-13).
• Key Claims at a Glance:
  • The complaint asserts at least claim 5, which depends from independent method claim 1 (Compl. ¶29).
  • The essential elements of Claim 1 include:
    • Displaying a GUI with a graphical representation of network nodes, including first and second edge nodes and intervening router nodes.
    • Displaying a graphical representation of multiple paths available between the edge nodes.
    • Selecting a path from the displayed plurality in response to a user input.
    • Initiating configuration of the router nodes on the selected path in response to the selection.
  • The complaint alleges infringement of "one or more claims" (Compl. ¶28).

Multi-Patent Capsule

• Patent Identification: U.S. Patent No. 7,420,975, "Method and Apparatus For High-Speed Frame Tagger," Issued Sep. 2, 2008 (Compl. ¶9).
• Technology Synopsis: The patent describes an apparatus to offload the task of packet inspection from a network's main processor. The invention is a dedicated hardware logic block that performs a high-speed, multi-pass comparison of incoming data packets against predetermined values to determine the packet's protocol type. Based on this determination, the logic block "tags" the packet to steer it to the appropriate internal destination (e.g., a central processor or a network processor) without slowing down data flow (’975 Patent, Abstract; col. 1:10-27).
• Asserted Claims: The complaint asserts at least claim 5, which depends from independent apparatus claim 1. Other independent claims include 11 and 17 (Compl. ¶45).
• Accused Features: The complaint accuses the ExtremeSwitching X695's Access Control List (ACL) functionality, specifically its "First Stage ACL/VLAN processor," of acting as the claimed "protocol determination logic block" to perform multi-pass packet analysis and tagging (Compl. ¶¶46-47).

III. The Accused Instrumentality

• Product Identification: The complaint primarily accuses the ExtremeSwitching X695 network switch and the ExtremeWireless V10.41.01 software, which is part of the Extreme Management Center suite of products (Compl. ¶¶20, 30, 45).
• Functionality and Market Context:
  • The ExtremeSwitching X695 is identified as a "High-performance 10/25 Gigabit Aggregation Switch" designed for enterprise LAN and top-of-rack applications (Compl. p. 5). The complaint alleges it performs high-speed signal transmission and packet tagging using a multi-stage ACL architecture (Compl. ¶¶20, 46-47). A marketing screenshot shows the physical X695 switch (Compl. p. 5).
  • The ExtremeWireless V10.41.01 software provides a GUI for managing network devices (Compl. ¶30). It includes tools to create topology maps of the network, view device connections, and configure routing protocols like Open Shortest Path First (OSPF) to manage traffic flow (Compl. ¶¶30-31, 34). The complaint alleges this software is used for managing huge industrial wireless networks and large-scale enterprises (Compl. ¶29). A screenshot from a user manual shows a network topology map generated by the software (Compl. p. 8).

IV. Analysis of Infringement Allegations

’692 Patent Infringement Allegations

• Identified Points of Contention:
  • Scope Questions: The patent’s background focuses heavily on long-haul WAN "transport systems" that interconnect geographically separate facilities (’692 Patent, col. 2:26-33). The infringement analysis raises the question of whether the internal architecture of a single aggregation switch, the ExtremeSwitching X695, can be considered a "transport system" within the meaning of the claims.
  • Technical Questions: The complaint alleges that the X695 performs the specific steps of converting, recovering clock/data, and reconverting, but provides no technical documentation to support how the switch's internal data path achieves this. A central question will be what evidence demonstrates that the accused switch performs these specific functions, rather than merely passing data through standard switching application-specific integrated circuits (ASICs).

’646 Patent Infringement Allegations

• Identified Points of Contention:
  • Scope Questions: The patent defines "edge node" in the specific context of "media aggregation managers" that act as proxies for communities of users in a VoIP network (’646 Patent, col. 6:35-40). The infringement analysis will question whether the general-purpose wireless controllers and access points managed by the accused ExtremeWireless software meet this specific definition.
  • Technical Questions: Claim 1 requires a user to "select[] a path" which then "initiat[es] configuration." The complaint's evidence shows a user selecting a routing protocol (e.g., OSPF), which then automatically calculates the best path (Compl. ¶¶34-35). This raises the question of whether selecting a routing method is the same as directly "selecting a path" from a displayed list of multiple options, as contemplated by the patent.

V. Key Claim Terms for Construction

For the ’692 Patent:

• The Term: "transport system"
• Context and Importance: This term is critical because the patent’s invention is a transceiver for use with such a system. The definition will determine if the patent's scope is limited to long-haul networks or if it can read on the internal workings of a single piece of networking equipment like the accused switch.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Narrower Interpretation: The patent’s background section repeatedly frames the problem in the context of interconnecting geographically separate LANs over "Carrier WAN technologies," "SONET-based TDM infrastructure," and "Metro," "Long Haul," and "Ultra Long Haul" systems (’692 Patent, col. 2:11-15, 3:5-8). This suggests a system external to and connecting client devices.
  • Evidence for a Broader Interpretation: The claims themselves do not contain an explicit distance or architectural limitation. A plaintiff may argue that any medium that allows a signal to be "transmitted and received" qualifies, including an internal backplane or bus within a switch (’692 Patent, col. 4:6-9).

For the ’646 Patent:

• The Term: "selecting a path from the plurality of paths in response to a first user input"
• Context and Importance: This term defines the core user action that triggers the patented configuration method. The infringement case may turn on whether the accused software’s user interaction—which appears to involve selecting a routing protocol—meets this limitation. Practitioners may focus on this term because it goes to the heart of the operational difference between the patented concept and standard network management.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Narrower Interpretation: The detailed description and figures suggest a direct action where a user is presented with a "prioritized list of potential paths" and makes a selection from that list (’646 Patent, col. 3:31-32; Fig. 7). This implies the user chooses a specific, pre-identified route.
  • Evidence for a Broader Interpretation: A plaintiff could argue that "selecting a path" should be construed more broadly to include any user input that results in the selection of a path, even if that selection is performed algorithmically by a protocol (like OSPF) that the user chose to enable.

VI. Other Allegations

• Indirect Infringement: For all three patents, the complaint alleges induced infringement. The stated basis is that Defendant supplies the accused products to customers and end-users with "instructions on how to operate the Accused Instrumentalities in an infringing manner," making this information available on its website and in other publications (Compl. ¶¶23, 39, 53).
• Willful Infringement: Willfulness is alleged for all three patents. The allegations are pleaded in the alternative: either Defendant had knowledge of the infringement "at least as of the date of this Complaint" (implying post-filing willfulness) or it was willfully blind to the infringement pre-suit by allegedly adopting "a policy of not reviewing the patents of others" in its industry (Compl. ¶¶22, 38, 52).

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

• A core issue will be one of definitional scope: can terms rooted in specific technical contexts, such as the long-haul "transport system" of the ’692 Patent and the VoIP-centric "media aggregation manager" of the ’646 Patent, be construed broadly enough to cover the accused general-purpose aggregation switch and wireless network management software?
• A key operational question will be one of functional mismatch: does the accused software’s user action of selecting a routing protocol (OSPF), which then algorithmically determines a route, satisfy the ’646 Patent’s claim limitation of a user directly "selecting a path" from a displayed list of options?
• A central evidentiary question will be one of technical proof: the complaint makes conclusory allegations about the internal operations of the accused X695 switch to meet the limitations of the '692 and '975 patents. The case will likely depend on whether discovery can produce evidence to substantiate that the switch's internal architecture performs the specific signal processing and multi-pass logic steps as claimed, beyond what is described in high-level product documentation.