DCT

1:25-cv-01254

Morris Routing Tech LLC v. Microsoft Corp

I. Executive Summary and Procedural Information

Parties & Counsel:
- Plaintiff: Morris Routing Technologies, LLC (Texas)
- Defendant: Microsoft Corporation (Washington)
- Plaintiff’s Counsel: Devlin Law Firm LLC
Case Identification: 1:25-cv-01254, W.D. Tex., 08/07/2025
Venue Allegations: Plaintiff alleges venue is proper in the Western District of Texas because Microsoft maintains regular and established places of business in Austin and San Antonio and has committed acts of infringement in the district.
Core Dispute: Plaintiff alleges that Defendant’s global cloud network and related network solutions, including Microsoft Azure, infringe seven patents related to segment-based routing for data packets.
Technical Context: The technology at issue, segment routing (SR), is a network routing protocol that simplifies traffic engineering and management in large-scale networks by embedding path information into the data packet header itself.
Key Procedural History: The complaint alleges that Microsoft has been involved for over a decade with the Internet Engineering Task Force (IETF) working group (SPRING) responsible for standardizing SR technology, including co-authoring an SR-related technical standard (RFC 9256). This alleged long-term involvement and knowledge may be central to Plaintiff's claims of willful infringement.

Case Timeline

Date	Event
2012-12-27	Earliest Priority Date for all Patents-in-Suit
2016-06-23	Date of Microsoft presentation on SR-MPLS (SWAN)
2019-08-20	U.S. Patent No. 10,757,010 Issues
2020-02-25	U.S. Patent No. 10,574,562 Issues
2020-05-12	U.S. Patent No. 10,652,133 Issues
2020-05-12	U.S. Patent No. 10,652,134 Issues
2020-10-13	U.S. Patent No. 10,805,204 Issues
2023-09-12	U.S. Patent No. 11,757,756 Issues
2023-10-10	U.S. Patent No. 11,784,914 Issues
2025-05-10	Date of Microsoft presentation on SRv6
2025-08-07	Complaint Filing Date

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

U.S. Patent No. 10,652,133 - Routing Methods, Systems, and Computer Program Products (Issued May 12, 2020)

The Invention Explained

Problem Addressed: Traditional internet routing protocols, such as IP/MPLS, required intermediate network nodes to maintain extensive "state" information for each data flow, leading to complexity and scalability problems as network traffic grew (Compl. ¶¶14-15; ’133 Patent, col. 2:7-59). These methods made traffic engineering complex and limited the ability to define explicit paths for data packets (Compl. ¶¶14-15).
The Patented Solution: The invention proposes a "path-based protocol address" where the entire path for a data packet is encoded as a sequence of "path segment identifiers" within the packet itself ('133 Patent, col. 20:11-21). This allows a source node to dictate the route, removing the need for intermediate nodes to maintain per-flow state information; they simply process the current segment identifier and forward the packet to the next segment in the sequence (Compl. ¶17; ’133 Patent, col. 18:55-20:45). Figure 2 of the patent illustrates a method where a current node detects a data unit with a path-based address, identifies the "current-next path segment," determines the corresponding network interface, and sends the data to the next node.
Technical Importance: This source-routing approach simplifies network architecture, reduces the processing load on routers, and provides operators with more precise control over traffic paths, which is critical for traffic engineering and service chaining in modern cloud and SD-WAN networks (Compl. ¶¶17, 21, 26).

Key Claims at a Glance

Independent Claim 12:
- A method comprising:
- detecting, by a current node, data in a data unit that includes a first path-based protocol address comprising a plurality of path segment identifiers that identify respective path segments of a network path;
- detecting, based on the current location, a current-next path segment identifier;
- determining, based on the current-next path segment identifier, a current-next network interface; and
- sending, via the current-next network interface, the data to the next node.
The complaint reserves the right to assert additional claims (Compl. ¶57).

U.S. Patent No. 10,574,562 - Routing Methods, Systems, and Computer Program Products (Issued Feb. 25, 2020)

The Invention Explained

Problem Addressed: The patent addresses the challenge of creating new routing addresses and paths in a network where traditional addressing schemes (like those described in IETF RFC 791) create a rigid distinction between names, addresses, and routes, thereby limiting flexibility (’562 Patent, col. 2:32-42).
The Patented Solution: The invention discloses a system where a node can generate a new "segment identifier" (segment ID) for routing by combining a globally unique "index value" with a "base value" that corresponds to a set of segment routing values. This allows for the dynamic calculation of path segments and next-hop identifiers, creating a flexible and scalable routing system (’562 Patent, Abstract; col. 1:65-2:2). This is distinct from simply looking up a pre-determined address in a static table.
Technical Importance: This method of dynamically calculating segment identifiers from base and index values provides a structured way to create and manage large numbers of explicit routing paths, which is a foundational element for scalable segment routing implementations (Compl. ¶¶20-21).

Key Claims at a Glance

Independent Claim 1:
- A system comprising a first node configured to:
- receive a packet, wherein the packet comprises an internet protocol (IP) header; and
- update the packet by writing information to a destination address of the IP header, wherein the information comprises a segment identifier (SID).
The complaint reserves the right to assert additional claims (Compl. ¶65).

U.S. Patent No. 10,652,134 - Routing Methods, Systems, and Computer Program Products

Patent Identification: U.S. Patent No. 10,652,134, "Routing Methods, Systems, and Computer Program Products," issued May 12, 2020.
Technology Synopsis: This patent is directed at methods for generating a set of segment identifiers that encode a specific network path. The invention focuses on storing these segment identifiers in tables at each enabled node along the path and adding the set of identifiers to a packet header to direct its routing.
Asserted Claims: At least Claim 1 is asserted (Compl. ¶72).
Accused Features: The accused features are Microsoft's networks and solutions that allegedly use SR functionality consistent with the SR RFCs (Compl. ¶¶51, 72).

U.S. Patent No. 10,757,010 - Routing Methods, Systems, and Computer Program Products

Patent Identification: U.S. Patent No. 10,757,010, "Routing Methods, Systems, and Computer Program Products," issued August 20, 2019.
Technology Synopsis: This patent describes a method for routing data packets using a path-based protocol address. The invention details how a current node identifies the next node in the path by detecting a "current-next path segment identifier" from a plurality of such identifiers contained within the packet's address.
Asserted Claims: At least Claim 2 is asserted (Compl. ¶80).
Accused Features: The accused features are Microsoft's networks and solutions that allegedly use SR functionality consistent with the SR RFCs (Compl. ¶¶51, 80).

U.S. Patent No. 10,805,204 - Routing Methods, Systems, and Computer Program Products

Patent Identification: U.S. Patent No. 10,805,204, "Routing Methods, Systems, and Computer Program Products," issued October 13, 2020.
Technology Synopsis: This patent discloses a method for creating a path-based protocol address by identifying a sequence of nodes in a network path. The invention focuses on a system that detects this path information and composes a protocol address that identifies the destination node to the source node for transmitting data.
Asserted Claims: At least Claim 15 is asserted (Compl. ¶88).
Accused Features: The accused features are Microsoft's networks and solutions that allegedly use SR functionality consistent with the SR RFCs (Compl. ¶¶51, 88).

U.S. Patent No. 11,757,756 - Routing Methods, Systems, and Computer Program Products

Patent Identification: U.S. Patent No. 11,757,756, "Routing Methods, Systems, and Computer Program Products," issued September 12, 2023.
Technology Synopsis: This patent is directed at a method of generating segment identifiers where at least one identifier is from a "scope-specific" address space. This allows a segment identifier to be valid within a particular network region (a "scope") and used to identify a path to a next region, enhancing routing flexibility across different network domains.
Asserted Claims: At least Claim 10 is asserted (Compl. ¶96).
Accused Features: The accused features are Microsoft's networks and solutions that allegedly use SR functionality consistent with the SR RFCs (Compl. ¶¶51, 96).

U.S. Patent No. 11,784,914 - Routing Methods, Systems, and Computer Program Products

Patent Identification: U.S. Patent No. 11,784,914, "Routing Methods, Systems, and Computer Program Products," issued October 10, 2023.
Technology Synopsis: This patent describes a system for selecting a sequence of segment identifiers based on a specified policy and storing them in a packet header. The invention focuses on selecting a path from a plurality of available paths and using the corresponding identifiers to direct traffic, a key element of traffic engineering.
Asserted Claims: At least Claim 1 is asserted (Compl. ¶104).
Accused Features: The accused features are Microsoft's networks and solutions that allegedly use SR functionality consistent with the SR RFCs (Compl. ¶¶51, 104).

III. The Accused Instrumentality

Product Identification

The Accused Instrumentalities are "Microsoft's networks and network solutions, including Azure and related products and services," which allegedly "support the functionality specified in the SR RFCs" (Compl. ¶51).

Functionality and Market Context

The complaint alleges that Microsoft operates a global cloud network and uses Segment Routing (SR) technology, including both SR over MPLS (SR-MPLS) and SR over IPv6 (SRv6), to manage data traffic (Compl. ¶49). The complaint provides a screenshot from a 2016 Microsoft presentation depicting a "SWAN Architecture" diagram, which shows a system using a "Centralized TE Engine" to manage traffic in an MPLS network, an architecture the complaint links to segment routing (Compl. ¶49, p. 12). A second screenshot from a 2025 presentation allegedly shows Microsoft's use of SRv6 to encode a multi-hop path into an IPv6 destination address for routing in an "AI Backend Network" (Compl. ¶50, p. 13). The complaint asserts that Microsoft adopted SR to overcome the shortcomings of traditional routing technologies and uses it to minimize network state, enable edge programming, and reduce protocol complexity (Compl. ¶¶50, 32-33).

IV. Analysis of Infringement Allegations

The complaint references claim charts in Exhibits H and I that allegedly detail infringement of the ’133 and ’562 patents, respectively; however, these exhibits were not filed with the complaint (Compl. ¶¶57, 65). The infringement theory must therefore be summarized from the complaint's narrative allegations.

U.S. Patent No. 10,652,133 Infringement Allegations

The complaint alleges that Microsoft's networks directly infringe at least claim 12 of the ’133 Patent by using segment routing (Compl. ¶56). The core theory is that when Microsoft's networks route data, a network node (the "current node") receives a data packet containing a sequence of segment identifiers that define the packet's path (the "first path-based protocol address"). That node then identifies the next hop in the path ("current-next path segment identifier"), determines the physical network port corresponding to that hop ("current-next network interface"), and forwards the packet (Compl. ¶¶17, 49-50). This alleged operation is presented as mapping directly onto the elements of claim 12.

U.S. Patent No. 10,574,562 Infringement Allegations

The complaint alleges that Microsoft's networks directly infringe at least claim 1 of the ’562 Patent (Compl. ¶64). Claim 1 requires a node to update a packet's IP header with a "segment identifier (SID)." The complaint's technical presentation on SRv6 alleges that Microsoft's network nodes encode an "SRv6 parse" containing path information "in the destination ip address" of the packet (Compl. ¶50, p. 13). This alleged functionality of writing a segment identifier into the IP destination address field of a packet appears to be the basis for the infringement allegation against claim 1 of the ’562 patent.

Identified Points of Contention

Scope Questions: The patents describe a "path-based protocol address." A central question may be whether the specific implementations of SR-MPLS label stacks or SRv6 headers used by Microsoft (as defined by IETF standards) fall within the scope of this term as it is defined and used in the patents.
Technical Questions: What evidence demonstrates that Microsoft's network nodes perform the specific step of "detecting...a current-next path segment identifier" as required by claim 12 of the '133 patent, versus merely processing a label or pointer according to standard MPLS or IPv6 protocols? For the '562 patent, does the information Microsoft allegedly writes to the IP header function as the claimed "segment identifier," and does this update occur in the manner claimed?

V. Key Claim Terms for Construction

The Term: "path segment identifier" (from '133 Patent, claim 12)
- Context and Importance: This term is the fundamental unit of routing information in the claimed invention. Its construction will be critical to determining whether the MPLS labels or IPv6 address segments used in Microsoft's allegedly SR-compliant networks meet the claim limitations. Practitioners may focus on this term because the patents' descriptions of these identifiers may differ in subtle but important ways from the standardized identifiers (SIDs) defined in the IETF SR RFCs that Microsoft is accused of practicing.
- Intrinsic Evidence for Interpretation:
  - Evidence for a Broader Interpretation: The specification states that path segment identifiers "identify respective path segments of a network path" and can be used in a "path-based protocol address" ('133 Patent, col. 20:11-15). This functional language may support a construction that is not limited to a specific format and could encompass various types of routing instructions.
  - Evidence for a Narrower Interpretation: The detailed description provides specific examples of how path segment identifiers are structured and used in sequences, such as in the address representations in Figures 6A-6E ('133 Patent, col. 21:12-23:7). These embodiments could be cited to argue for a narrower construction tied to the specific structures disclosed.
The Term: "segment identifier (SID)" (from '562 Patent, claim 1)
- Context and Importance: This term is the core piece of information written to the packet header to direct routing. The infringement analysis for the '562 patent hinges on whether the information Microsoft's systems allegedly write to an IP header constitutes a "segment identifier" as claimed.
- Intrinsic Evidence for Interpretation:
  - Evidence for a Broader Interpretation: The abstract describes calculating a "segment identifier (segment ID) based on the index value and the base value" and a "next hop segment ID" to forward a packet (’562 Patent, Abstract). This suggests the term refers functionally to a calculated routing instruction.
  - Evidence for a Narrower Interpretation: Claim 1 recites writing the SID to the "destination address" of the IP header. This explicit location may support a narrower construction that requires the SID to be placed in that specific field, potentially excluding other forms of packet header modification.

VI. Other Allegations

Indirect Infringement: The complaint does not contain specific factual allegations supporting claims for either induced or contributory infringement. The counts focus on allegations of direct infringement (Compl. ¶¶56, 64, 72, 80, 88, 96, 104).
Willful Infringement: The complaint alleges facts that may support a claim of willful infringement. It asserts that Microsoft has been involved with the IETF's segment routing standardization process for "over a decade," has co-authored an SR-related standard (RFC 9256), and is a member of ETSI's NFV ISG, which analyzes SRv6 (Compl. ¶¶34, 42, 47-48). These allegations suggest that Microsoft had pre-suit knowledge of SR technology and, by extension, potentially the patents-in-suit. The prayer for relief requests a declaration that the case is exceptional under 35 U.S.C. § 285 (Compl., p. 22, ¶C).

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

A core issue will be one of claim scope and standardization: Can the patent claims, which describe a specific "path-based protocol address" and "segment identifiers," be construed to cover the industry-standard Segment Routing implementations (SR-MPLS and SRv6) that Microsoft allegedly practices according to IETF RFCs? The case may turn on whether the patented inventions are coextensive with the standards or claim a specific implementation that differs from them.
A second key issue will be evidentiary: Beyond high-level presentations, what technical evidence can Plaintiff produce to demonstrate that Microsoft's vast and complex network infrastructure, including Azure, actually performs each step of the asserted method claims? Proving that the operational reality of Microsoft's live network maps to every claim element will be a significant factual hurdle.
A third question will relate to willfulness: Given Microsoft's alleged deep and long-standing involvement in the standardization of the accused SR technology, a central issue will be whether this involvement constitutes pre-suit knowledge of the patents and egregious conduct sufficient to support a finding of willful infringement and render the case exceptional.