NetScout Systems Inc v. Longhorn HD LLC

1. Case Identification

• Case #: IPR2021-01555
• Patent #: 6,954,790
• Filed: October 6, 2021
• Petitioner(s): NetScout Systems, Inc.
• Patent Owner(s): Longhorn HD LLC.
• Challenged Claims: 1-4 and 7

2. Patent Overview

• Title: Network-Based Mobile Workgroup System
• Brief Description: The ’790 patent describes a network-based mobile workgroup system that provides secure communication and mobility management for its members. The system integrates Virtual Private Network (VPN) and firewall functionality, using policy rules defined by a service manager and enforced by mobile service routers to control user access to network resources.

3. Grounds for Unpatentability

Ground 1: Obviousness over Akhtar and Schneider - Claims 1-4 and 7 are obvious over Akhtar in view of Schneider.

• Prior Art Relied Upon: Akhtar (Patent 6,769,000) and Schneider (Patent 6,408,336).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that the combination of Akhtar’s mobile VPN architecture with Schneider’s workgroup-based security policies renders the challenged claims obvious. Neither reference was considered during original prosecution.
    • Petitioner asserted that Akhtar teaches a comprehensive IP-based mobile communications architecture that functions as a network-based mobile VPN. This system includes the core components recited in claim 1: a plurality of “mobile client nodes” (Akhtar’s Mobile Nodes or MNs), a plurality of “mobile service router nodes” (Akhtar’s Local Service Functions (LSFs) and Network Service Functions (NSFs)), and a “network address identifier (NAI)” used to uniquely identify and authenticate users. While Akhtar discloses firewalls and user-specific policies (e.g., bandwidth), it does not explicitly teach applying firewall filters based on a user’s workgroup membership.
    • Petitioner contended that Schneider remedies this deficiency by teaching a VPN system where access to data is controlled based on a user’s membership in specific “user groups.” Schneider’s system uses distributed “access filters,” which function as firewalls, to apply policies that grant or deny resource access based on these group affiliations. Petitioner argued Schneider’s “user groups” are analogous to the ’790 patent’s claimed “mobile workgroup,” thus providing the missing limitation of claim 1(d): “a set of firewall filters and route policies with which the workgroup is protected.”
    • For the dependent claims, Petitioner argued that Akhtar’s base system already teaches their limitations. Specifically, Akhtar discloses using the NAI to authenticate a user at the start of and during a session (claim 2), tying a user’s allocated IP address to their NAI via DNS and directory services (claim 3), and maintaining a stable IP address for the duration of a network session (claim 4). Claim 7, which recites various routing methods, was also allegedly taught by Akhtar’s detailed description of communication protocols for intra-domain, inter-domain, and remote access routing.
  • Motivation to Combine: Petitioner argued a person of ordinary skill in the art (POSITA) would combine Akhtar and Schneider to improve the security and functionality of Akhtar’s mobile architecture. Both references address the challenge of providing secure network access for an increasingly mobile user base. A POSITA would have recognized the benefit of implementing Schneider’s well-understood method of group-based access control into Akhtar’s robust mobile VPN to provide more granular, enterprise-level security. The combination was framed as the predictable integration of a known security feature (group-based filtering) into a similar, contemporary system to enhance its capabilities.
  • Expectation of Success: Petitioner asserted a POSITA would have had a high expectation of success in this combination. The integration would primarily involve software and policy modifications rather than complex hardware changes, and adding Schneider's known policy enforcement logic to Akhtar's network architecture would yield predictable results without introducing technical uncertainty.

4. Arguments Regarding Discretionary Denial

• Petitioner presented arguments that discretionary denial of the petition would be improper under both 35 U.S.C. §325(d) and §314(a) (Fintiv factors).
• Petitioner argued against denial under §325(d) because the primary references, Akhtar and Schneider, are new and were never presented to or considered by the examiner during the original prosecution. Therefore, the petition raised non-cumulative art and arguments that were material to patentability.
• Petitioner argued against discretionary denial under Fintiv because the Patent Owner had withdrawn the ’790 patent from the co-pending district court case against the Petitioner. As a result, no parallel proceeding existed that could resolve the invalidity dispute, rendering the Fintiv factors in favor of institution.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-4 and 7 of the ’790 patent as unpatentable.