DCT
2:18-cv-00058
Sonus Networks Inc v. Metaswitch Networks Ltd
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Sonus Networks, Inc., d/b/a/ Ribbon Communications Operating Company (Delaware)
- Defendant: Metaswitch Networks Ltd (United Kingdom) and Metaswitch Networks Corporation (Delaware)
- Plaintiff’s Counsel: Baker Botts L.L.P.
- Case Identification: 2:18-cv-00058, E.D. Tex., 03/08/2018
- Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Texas because Defendant Metaswitch maintains a regular and established place of business in Frisco, Texas, within the district.
- Core Dispute: Plaintiff alleges that Defendant’s session border controller and network management products infringe five patents related to network resource management, dynamic traffic classification, session identification, and service provisioning interfaces.
- Technical Context: The technologies at issue concern the management of real-time communications, such as Voice over IP (VoIP), in packet-based networks, which is a foundational element of modern telecommunications infrastructure.
- Key Procedural History: The complaint does not mention any prior litigation between the parties, Inter Partes Review (IPR) proceedings involving the asserted patents, or relevant licensing history.
Case Timeline
| Date | Event |
|---|---|
| 2001-09-21 | U.S. Patent No. 7,310,663 Priority Date |
| 2003-03-17 | U.S. Patent No. 7,460,536 Priority Date |
| 2003-12-03 | U.S. Patent No. 7,702,768 Priority Date |
| 2004-09-29 | U.S. Patent No. 7,602,710 Priority Date |
| 2007-12-18 | U.S. Patent No. 7,310,663 Issue Date |
| 2008-12-02 | U.S. Patent No. 7,460,536 Issue Date |
| 2009-05-06 | U.S. Patent No. 8,605,589 Priority Date |
| 2009-10-13 | U.S. Patent No. 7,602,710 Issue Date |
| 2010-04-20 | U.S. Patent No. 7,702,768 Issue Date |
| 2013-06-01 | Date of Accused Product Manuals (Perimeta Guides) |
| 2013-12-10 | U.S. Patent No. 8,605,589 Issue Date |
| 2018-03-08 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,602,710 - Controlling Time-Sensitive Data in a Packet-Based Network
The Invention Explained
- Problem Addressed: The patent describes prior art network management systems that relied on a centralized server with knowledge of the entire network topology to manage resources. This approach was described as increasing processing time and being less scalable (Compl. ¶19; ’710 Patent, col. 2:36-54).
- The Patented Solution: The invention proposes a method to manage network resources without centralized topological knowledge. It involves monitoring the state of data packets for a specific call (e.g., transmitted, received, lost), associating this information with a "logical trunk group," calculating a performance statistic from this data, and then adjusting a resource parameter (e.g., bandwidth allocation) in response to that statistic (’710 Patent, Abstract; col. 3:31-44).
- Technical Importance: This approach enabled more dynamic, scalable, and decentralized quality of service (QoS) management for real-time traffic in IP networks.
Key Claims at a Glance
- The complaint asserts independent method Claim 1 (Compl. ¶22).
- The essential elements of Claim 1 are:
- collecting information relating to a state (transmitted, received, queued, lost, or combination thereof) of a set of data packets associated with a telephone call;
- associating the information with a logical trunk group from a plurality of logical trunk groups;
- determining a performance statistic associated with the call, trunk group, or network based on the information; and
- adjusting a resource parameter associated with the network in response to the performance statistic.
U.S. Patent No. 8,605,589 - Dynamic Classification and Grouping of Network Traffic for Service Application
The Invention Explained
- Problem Addressed: The patent identifies a problem with prior systems that grouped subscribers into pre-configured, static groups, making it difficult to provide consistent service treatment for a subscriber's traffic across all network equipment used to deliver the service (Compl. ¶32; ’589 Patent, col. 1:46-54).
- The Patented Solution: The invention describes a method for dynamically applying services based on traffic classification. The method involves receiving a traffic flow, matching it to "classification groups" by comparing attributes of an event in the flow with the groups' entry criteria, identifying one or more service definitions based on the assigned groups, "reconciling" those definitions, and then providing a service based on the reconciled definitions (’589 Patent, Abstract; col. 2:5-24).
- Technical Importance: This technology allows for the application of policies and services to network traffic based on its real-time characteristics rather than on static, pre-configured subscriber profiles.
Key Claims at a Glance
- The complaint asserts independent method Claim 1 (Compl. ¶35).
- The essential elements of Claim 1 are:
- receiving, at a network server, a traffic flow;
- matching the traffic flow to classification groups by determining a first event, comparing its attributes with entry criteria, and assigning it to matching groups;
- identifying one or more service definitions for the traffic flow based on the assigned classification groups;
- reconciling the one or more service definitions; and
- providing a service to the traffic flow based on the reconciled service definitions.
U.S. Patent No. 7,460,536 - User and Session Identification based on Connections, Protocols and Protocol Fields
- Technology Synopsis: The patent addresses the problem of applying distinct service levels to data packets from different users or applications that share the same physical network connection (Compl. ¶46; ’536 Patent, col. 1:29-54). The patented solution involves creating a unique "session identifier" for a data stream by combining a "connection identifier" (e.g., the physical port) with the communication protocol used, and then applying a pre-determined service level associated with that session identifier to each data packet (’536 Patent, Abstract).
- Asserted Claims: Claim 1 (Compl. ¶49).
- Accused Features: The complaint alleges infringement by the accused products' use of "VLAN tags" to distinguish traffic arriving on the same physical port and the application of service policies based on "adjacency matching," which uses the port and VLAN tag to identify the traffic (Compl. ¶51).
U.S. Patent No. 7,702,768 - XNM—An Interface for a Network Management System
- Technology Synopsis: The patent addresses inefficiencies in prior art network management systems that required clients to use system-specific libraries and languages, making them difficult to update when services changed (Compl. ¶57; ’768 Patent, col. 1:19-49). The invention provides an interface that receives commands in a "generic syntax," parses the command to identify descriptors, determines if the requested service is available, and, if so, generates and executes an "internal command in a second language" specific to the network device (’768 Patent, Abstract).
- Asserted Claims: Claim 1 (Compl. ¶60).
- Accused Features: The MetaView Network Management System, SIP Provisioning Server, and CommPortal are accused of infringement by providing various user interfaces (e.g., "graphical phone view") for clients to issue commands for services across the Metaswitch product range (Compl. ¶¶ 61, 63). A screenshot in the complaint shows a "Phone Profile Editor" interface for configuring phone settings (Compl. p. 29).
U.S. Patent No. 7,310,663 - Initiation Module for Initiating Network-Based Services
- Technology Synopsis: The patent addresses the prior art requirement for service providers to manually configure hardware and software for a subscriber to begin a new service (Compl. ¶66; ’663 Patent, col. 1:49-57). The solution is a method using two interfaces: a first interface for a service provider to define a service and its configuration information, and a second interface for a subscriber to self-register for and initiate that service automatically, without further action by the provider (’663 Patent, Abstract).
- Asserted Claims: Claim 1 (Compl. ¶69).
- Accused Features: The MetaView Network Management System is accused of being the provider's first interface, while CommPortal Web is accused of being the subscriber's second interface for self-activating services (Compl. ¶¶ 71-72). A screenshot of an "Add Services tab" illustrates a subscriber-facing interface for adding features to a phone service (Compl. p. 32).
III. The Accused Instrumentality
Product Identification
- The accused instrumentalities are Metaswitch's Perimeta Session Border Controller (SBC), MetaView Network Management System, SIP Provisioning Server, and CommPortal (Compl. ¶17).
Functionality and Market Context
- The complaint describes the Perimeta SBC as a product that manages real-time communication sessions by collecting packet statistics, routing messages based on policies and trunk group information, using VLANs to segregate traffic, and applying Quality of Service (QoS) via traffic prioritization and bandwidth policing (Compl. ¶¶ 24-27). A screenshot from product documentation shows the Perimeta system collects "VQM statistics" including "the number of RTP packets lost" (Compl. p. 9).
- The MetaView Network Management System and associated products are described as a suite providing interfaces for service providers and subscribers to provision, configure, and troubleshoot services across the Metaswitch product line (Compl. ¶¶ 61, 71).
- The complaint positions the accused products as direct competitors to Plaintiff's own portfolio of real-time communications products (Compl. ¶17).
IV. Analysis of Infringement Allegations
Infringement Allegations: '710 Patent
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| collecting information relating to a state of a set of data packets associated with a telephone call... | The Perimeta SBC products "collect statistics . . . including statistics on packets received, sent and dropped[.]" | ¶24 | col. 3:32-37 |
| associating the information with a logical trunk group from a plurality of logical trunk groups; | The Perimeta SBC products can "route messages based on . . . trunk group information." | ¶25 | col. 3:38-40 |
| determining a performance statistic... | The products determine "voice quality monitoring (VQM) statistics," which include metrics such as "The number of RTP packets lost" and "The number of RTP packets dropped locally." | ¶26 | col. 3:41-42 |
| adjusting a resource parameter associated with the packet-based network in part in response to the performance statistic. | The products provide "traffic prioritization" and "bandwidth policing" which includes "dynamically refining [] prioritization in response to network behavior" to manage network resources. | ¶27 | col. 3:43-46 |
Identified Points of Contention
- Scope Questions: The complaint alleges the accused product uses "trunk group information" for routing messages (Compl. ¶25). A potential point of contention may be whether this routing function satisfies the claim requirement of associating performance information with a logical trunk group for the purpose of resource management.
- Technical Questions: What evidence does the complaint provide that the accused product's "traffic prioritization" (Compl. ¶27) is adjusted in response to the "VQM statistics" (Compl. ¶26), as required by the claim's sequential logic? The complaint presents these as two distinct capabilities of the system, raising the question of a direct causal link.
Infringement Allegations: '589 Patent
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| receiving, at a network server, a traffic flow; | Metaswitch's session controller products receive traffic flows such as SIP requests. | ¶37 | col. 2:6-7 |
| matching, by the network server, the traffic flow to classification groups... [by] comparing attributes of the first event with entry criteria... | The products use "routing policy tables" with "entries that match particular features of a request" and use "Classes of Service" to distinguish different kinds of traffic. | ¶¶ 37-38 | col. 2:8-13 |
| identifying, by the network server, one or more service definitions for the traffic flow based on the classification groups... | The products apply "different treatment during routing" based on the identified "Class of Service." Adjacency configurations are also used to apply policies and settings. | ¶¶ 38-39 | col. 2:14-16 |
| reconciling, by the network server, the one or more service definitions for the traffic flow; and providing... a service to the traffic flow based on the reconciled... service definitions. | The products perform actions such as "traffic prioritization," and can apply "complex routing policy" by "consulting another table" to determine how to handle the traffic. A screenshot from product documentation outlines a "Routing policy" mechanism for determining how to route a SIP request (Compl. p. 14). | ¶¶ 40-41 | col. 2:17-21 |
Identified Points of Contention
- Scope Questions: A central question may be whether the combination of the accused product's "routing policy tables," "Classes of Service," and "adjacencies" (Compl. ¶¶ 37-39) constitutes the claimed "classification groups."
- Technical Questions: The complaint alleges the product can perform complex routing by "consulting another table" (Compl. ¶41), but it does not specify how this action meets the claim limitation of "reconciling... service definitions." The analysis may focus on whether this constitutes a mere sequential lookup or an actual reconciliation of potentially conflicting definitions.
V. Key Claim Terms for Construction
'710 Patent
- Term: "logical trunk group"
- Context and Importance: This term is central to the asserted claim, defining the entity with which performance statistics are associated. Its construction will determine whether the defendant's use of "trunk group information" for routing falls within the claim scope.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes a logical trunk group as a "virtual communication channel through a packet network" (’710 Patent, col. 5:55-56), which could support a broad, non-physical interpretation.
- Evidence for a Narrower Interpretation: The specification also describes logical trunk groups as being defined to be associated with specific gateways, representing "the set of pathways between the gateway 110 and the other gateway(s)" (’710 Patent, col. 7:25-29), potentially supporting a narrower construction tied to specific network endpoints.
'589 Patent
- Term: "reconciling"
- Context and Importance: This is a key active step in the claim method. The infringement theory depends on showing that the accused system does more than just apply a single matching policy; it must perform an act of reconciliation.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent does not provide an explicit definition for "reconciling." This lack of a specific definition may support a broader interpretation that covers any process of resolving how multiple applicable service definitions should be applied, including a hierarchical or multi-table lookup process.
- Evidence for a Narrower Interpretation: The absence of a detailed description or specific embodiment of the "reconciling" step could be argued to limit the term to its plain and ordinary meaning, which might require an explicit merging or conflict-resolution process not detailed in the complaint's allegations.
VI. Other Allegations
Indirect Infringement
- The complaint alleges inducement of infringement for each asserted patent. The basis for these allegations is that Defendant's "customer materials tout functionality" that falls within the scope of the claims, thereby encouraging customers to infringe (Compl. ¶¶ 29, 43, 54).
Willful Infringement
- The complaint alleges that Defendant has had knowledge of each patent "at least as early as service of this Complaint" (e.g., Compl. ¶¶ 20, 33, 47). The prayer for relief requests a finding that infringement "after the jury's verdict is willful," suggesting the willfulness claim is based on alleged post-suit conduct (Compl. p. 33).
VII. Analyst’s Conclusion: Key Questions for the Case
- Functional Causality: A central evidentiary issue will likely be whether the accused products' features perform the specific, ordered, and causally-linked steps recited in the method claims. For the ’710 patent, for example, a key question will be whether the product's "traffic prioritization" is in fact adjusted in response to the calculated "VQM statistics," or if these are two independent QoS functions that do not operate together as claimed.
- Definitional Scope: The dispute may turn on the construction of key claim terms. For the ’589 patent, a core issue will be one of definitional scope: can the term "reconciling," which implies resolving multiple inputs, be construed to read on the accused product's alleged function of "consulting another table" to apply a "complex routing policy"?
- System-Level Infringement: For the patents directed at network management and service activation systems (’768 and ’663), the analysis will likely focus on whether the combination of the accused MetaView, CommPortal, and provisioning server products operates as the single, integrated system required by the claims, or if they function as separate tools that, even when used together, do not practice the claimed methods.