DCT

2:25-cv-00783

Dynamic Mesh Networks Inc v. Cisco Systems Inc

Log In

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:25-cv-00783, E.D. Tex., 08/12/2025
  • Venue Allegations: Venue is asserted based on Defendant's regular and established places of business in the district, including a large campus in Richardson, Texas, and alleged acts of infringement occurring within the district.
  • Core Dispute: Plaintiff alleges that Defendant’s SD-WAN networking equipment and Webex collaboration products infringe three patents related to efficient data packet transmission and self-forming Voice-over-IP (VoIP) networks.
  • Technical Context: The patents address technologies for improving the reliability and efficiency of data networks, particularly for real-time applications like video and voice over wireless or multi-hop mesh networks.
  • Key Procedural History: The complaint alleges significant pre-suit history, including meetings in 2009 between the parties to discuss a potential partnership where Plaintiff's then-pending patent applications (which matured into the patents-in-suit) were allegedly disclosed to Cisco. The complaint also alleges that a notice letter identifying the patents and infringing products was sent to Cisco's CEO in June 2022, which allegedly received no response. This history forms the basis for the willfulness allegations.

Case Timeline

Date Event
2005-11-04 Earliest Priority Date for '762 Patent
2008-11-24 Earliest Priority Date for '852 and '000 Patents
2009-01-01 Plaintiff and Defendant allegedly meet to discuss technology
2013-07-02 U.S. Patent No. 8,477,762 Issues
2013-08-20 U.S. Patent No. 8,514,852 Issues
2015-06-02 U.S. Patent No. 9,049,000 Issues
2022-06-22 Plaintiff allegedly sends notice letter to Defendant's CEO
2025-08-12 Complaint Filed

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

U.S. Patent No. 8,514,852 - “Real time package transforms to avoid re-transmission” (Issued Aug. 20, 2013)

The Invention Explained

  • Problem Addressed: In networks with multiple hops (relays), such as wireless mesh networks, a single error in a transmitted data packet typically requires the entire packet to be re-sent from the original source. This process introduces significant delay (latency) and reduces network throughput, which is particularly detrimental for real-time applications like video streaming (Compl. ¶30; ’852 Patent, col. 1:35-45).
  • The Patented Solution: The invention proposes modifying a standard data packet into a "container packet" that includes redundant "repair/recovery information" for critical parts of the packet, such as the header. Each section, original and redundant, is protected by its own checksum. This allows an intermediate relay station that detects an error to use the redundant information to repair the packet on the fly and forward it, avoiding the delay of a full re-transmission from the source (Compl. ¶30; ’852 Patent, col. 2:18-28, Fig. 1).
  • Technical Importance: This approach aims to enhance the reliability of real-time data streams over inherently unreliable or "lossy" networks without resorting to fragmenting packets, which can be inefficient on certain types of networks (’852 Patent, col. 2:2-15).

Key Claims at a Glance

  • The complaint asserts at least Independent Claim 1 (Compl. ¶50).
  • Claim 1 (Method) requires:
    • modifying a standard format network packet by adding redundant information.
    • modifying at least one packet header to add a position offset reference number that points to the redundant information.
    • revising all checksums within the packet to agree with the modified contents.
    • transmitting the packet through a network.
    • if the received packet has a checksum mismatch, modifying it by retrieving the redundant information (using the offset reference) and replacing a corrupted portion.
    • revising all checksums again to agree with the newly repaired contents.
  • The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 9,049,000 - “Real-time packet transforms to avoid re-transmissions” (Issued June 2, 2015)

The Invention Explained

  • Problem Addressed: The patent, which is a continuation of the application that led to the ’852 patent, addresses the same problem of latency and throughput loss caused by packet re-transmissions in multi-hop networks (Compl. ¶35; ’000 Patent, col. 1:41-51).
  • The Patented Solution: The solution is substantively identical to that of the ’852 patent, involving the modification of packets to include redundant repair information and associated checksums, enabling intermediate nodes to perform error correction locally without requesting a re-transmission from the source (Compl. ¶35; ’000 Patent, Abstract; Fig. 1).
  • Technical Importance: This patent extends the same technical approach for enhancing the robustness of real-time data streams over collision-based or wireless networks (’000 Patent, col. 2:46-51).

Key Claims at a Glance

  • The complaint asserts at least Independent Claim 1 (Compl. ¶65).
  • Claim 1 (Method) requires:
    • modifying a packet by adding redundant information.
    • modifying at least one packet header to add a position offset reference number pointing to the redundant information.
    • revising all checksums to agree with the modified contents.
    • transmitting the packet, which includes checking the packet during transmission.
    • if a checksum mismatch is found, modifying the packet by retrieving the redundant information and replacing a corrupted portion.
    • calculating new checksums and revising all checksums to agree with the repaired packet.
  • The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 8,477,762 - “Self-forming VoIP Network” (Issued July 2, 2013)

The Invention Explained

  • Technology Synopsis: The patent addresses the problem of maintaining VoIP communications when a network or cluster of devices becomes disconnected from its central Session Initiation Protocol (SIP) server, which normally manages call routing (’762 Patent, col. 2:20-30). The invention provides a method for network nodes to independently construct and share a "local SIP registry," creating a decentralized, self-forming network that allows VoIP calls to be established and maintained within the isolated cluster without a central server (Compl. ¶39; ’762 Patent, Abstract).

Key Claims and Accusations

  • Asserted Claims: At least Independent Claim 1 is asserted (Compl. ¶80).
  • Accused Features: The complaint accuses Cisco Webex products of infringement, alleging they implement the claimed distributed SIP functionality for improved mobility and reliability (Compl. ¶13, ¶37, ¶39).

III. The Accused Instrumentality

  • Product Identification: The complaint names two groups of accused products:
    1. The "’852/’000 Accused Products," identified as "Cisco SD-WAN solutions and equipment with Forward Error Correction ('FEC')" (Compl. ¶13).
    2. The "’762 Accused Products," identified as "Cisco Webex" VoIP collaboration products and solutions (Compl. ¶13).
  • Functionality and Market Context:
    • The complaint alleges that Cisco's SD-WAN products with FEC perform functions that reduce re-transmission delays for real-time streams like video, which is the functionality accused of infringing the ’852 and ’000 patents (Compl. ¶30).
    • The complaint alleges that Cisco Webex products are VoIP-capable networks that implement "distributed SIP functionality" to enhance availability and reliability, particularly by enabling continuity of communications when connections to a central server are lost. This functionality is accused of infringing the ’762 Patent (Compl. ¶37-39).
    • Cisco is alleged to manufacture, market, and sell these products as integrated solutions, and to also offer support services to "plan, deploy, manage, and support" their use (Compl. ¶13-14, ¶53).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

Although the complaint incorporates claim charts by reference to Exhibits 4 and 5, these exhibits were not filed with the complaint. The following summary is based on the narrative allegations.

'852 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
modifying said packet by adding redundant information to the packet The complaint alleges that Cisco’s SD-WAN products with Forward Error Correction ("FEC") modify packets by adding redundant repair/recovery information. ¶13, ¶32 col. 2:18-22
modifying at least one packet header to add a position offset reference number that points to redundant information The complaint alleges that the accused products modify the packet header to add a reference number that points to the location of the added redundant information. ¶32 col. 5:35-44
revising all checksums within the packet as modified to agree with the packet contents as modified The complaint alleges that the accused products revise checksums within the packet after it has been modified to include the redundant information. ¶32 col. 5:52-62
if the modified packet...is determined to have a checksum mismatch as received, modifying the packet by retrieving the redundant information...and replacing a portion It is alleged that the accused products, upon receiving a packet with a checksum mismatch, use the redundant information to repair or reconstruct the lost or corrupted portion of the packet, thereby avoiding re-transmission. ¶30-31, ¶32 col. 6:20-31
modifying the packet...to return the packet's format to that of the standard packet format The complaint alleges that the accused products can modify the packet back to a standard format, for instance, before the packet and data information moves through the network after successful repair. ¶32 col. 6:15-18

'000 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
modifying said packet by adding redundant information to the packet As with the ’852 patent, the complaint alleges Cisco’s SD-WAN products with FEC add redundant repair information to packets to reduce re-transmission delays. ¶13, ¶35, ¶65 col. 2:20-22
modifying at least one packet header to add a position offset reference number that points to redundant information The infringement theory alleges that the accused products add a pointer or offset reference to the packet header to locate the redundant data. ¶65, Ex. 5 col. 5:35-44
revising all checksums within the packet as modified to agree with the packet contents as modified The complaint alleges the accused products update packet checksums after modification. ¶65, Ex. 5 col. 5:52-62
if the modified packet is determined to have a checksum mismatch as received, modifying the packet by retrieving the redundant information...and replacing a portion The complaint alleges that the accused products use the embedded redundant information to repair packets that have transmission errors, a core feature of the accused FEC systems. ¶35, ¶65 col. 6:20-31
calculating new checksums for packet; and revising all checksums within the packet as modified to agree with the contents of the modified packet The infringement theory alleges that after a packet is repaired using the redundant data, new checksums are calculated and applied to ensure the repaired packet is valid for subsequent transmission or processing. ¶65, Ex. 5 col. 6:27-31
  • Identified Points of Contention:
    • Scope Questions: A central question for the ’852 and ’000 patents will be whether the term "Forward Error Correction (FEC)" as implemented in Cisco's products is coextensive with the specific method of "adding redundant information" and using a "position offset reference number" as claimed. The defense may argue that FEC is a broad, known field and that its implementation does not practice the specific steps of the patent claims.
    • Technical Questions: For the ’762 patent, a key question will be whether the "survivability" features of Cisco Webex (Compl. ¶19, fn. 3) create and use a "local SIP registry" by "exchanging SIP information with other VoIP nodes in a cluster" as required by the claims, or if they operate on a different principle, such as a simpler pre-configured backup or failover mechanism that does not meet the "self-forming" limitations.

V. Key Claim Terms for Construction

For the ’852 and ’000 Patents:

  • The Term: "modifying said packet by adding redundant information"
  • Context and Importance: This term is the foundational step of the asserted claims. Its construction will determine whether the claims cover a broad range of error correction techniques or are limited to the specific implementation detailed in the specification. Practitioners may focus on this term because Cisco’s accused feature is identified as "Forward Error Correction," and the dispute will likely center on whether Cisco’s FEC method is the same as the patent's "adding redundant information."
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent abstract refers generally to sending a packet with "sufficient repair/recovery information" (’852 Patent, Abstract). The summary states the goal is to provide information to "repair/reconstruct the packet header without requesting a re-transmission" (’852 Patent, col. 4:13-15). This language may support a construction that covers various forms of added data used for error correction.
    • Evidence for a Narrower Interpretation: The detailed description and figures show a very specific implementation where key fields from the original header (e.g., "DST MAC," "SRC MAC") are duplicated and placed in a separate location within the packet, pointed to by a "DLEN" offset value (’852 Patent, Fig. 3, col. 5:6-14, col. 5:35-44). This may support a narrower construction limited to duplicating specific header fields and using an explicit offset pointer, potentially excluding other forms of FEC.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement for all three patents. Inducement is primarily based on allegations that Cisco instructs and encourages customers to use the accused products in an infringing manner through user guides, technical documentation, marketing materials, and support services (Compl. ¶51-53, ¶66-68, ¶81-83). The complaint provides URLs to Cisco's website as evidence of these instructions (Compl. ¶12, fn. 1; ¶19, fn. 3).
  • Willful Infringement: The complaint makes detailed allegations to support willfulness. It claims Cisco had pre-suit knowledge of the technology and pending patents from partnership discussions in 2009 (Compl. ¶41-42). It further alleges that a "2022 Notice Letter" was sent to Cisco's CEO, explicitly identifying the patents-in-suit and the accused products, and that Cisco never responded, allegedly constituting deliberate and willful conduct (Compl. ¶44-47, ¶62, ¶77, ¶92).

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

  1. Definitional Scope vs. Technical Operation: A primary issue for the ’852 and ’000 patents will be whether Cisco's commercially-available "Forward Error Correction" (FEC) technology operates in the specific manner required by the claims—namely, by adding duplicated header information and using an offset pointer for repair—or if it is a technically distinct, non-infringing form of error correction.
  2. Functionality of "Survivability" Features: For the ’762 patent, the case will likely turn on an evidentiary question of how Cisco Webex's "survivability" features actually work. The key question for the court will be whether these features create a "distributed SIP registry" through dynamic information exchange among nodes, as claimed, or if they are a more conventional, pre-configured failover system that does not meet the claim limitations.
  3. Impact of Pre-Suit History on Willfulness: The detailed allegations of 2009 partnership discussions and a 2022 notice letter to the CEO create a significant question regarding Cisco's state of mind. A central issue for trial will be whether Plaintiff can prove this history, and if so, whether Cisco’s continued alleged infringement in the face of such notice was objectively reckless, potentially justifying enhanced damages.