Cisco Systems Inc v. Parity Networks LLC

1. Case Identification

• Case #: Unassigned
• Patent #: 7,103,046
• Filed: October 4, 2019
• Petitioner(s): Cisco Systems, Inc.
• Patent Owner(s): Parity Networks, LLC
• Challenged Claims: 1-11

2. Patent Overview

• Title: Method and Apparatus for Intelligent Sorting and Process Determination of Data Packets Destined to a Central Processing Unit of a Router or Server on a Data Packet Network
• Brief Description: The ’046 patent discloses a network node, such as a router, that categorizes incoming data packets to mitigate denial-of-service (DoS) attacks. The system sorts packets destined for the central processing unit (CPU) into at least three categories based on their source—trusted, suspect, and unsure—and processes them according to a priority listing to prevent the CPU from being overloaded.

3. Grounds for Unpatentability

Ground 1: Claims 1-11 are obvious over Connor, alone or in view of Maher and/or Schuba.

• Prior Art Relied Upon: Connor (Patent 7,164,678), Maher (Patent 7,058,974), and Schuba (Patent 6,725,378).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Connor discloses the core structural elements of independent claim 1: a network node (receiver station) with packet processors (controller), a network access controller (NAC) (queues and driver), a queue set for processed packets, and a CPU (processing unit) that pulls packets from the queues based on priority. Petitioner contended that the key limitation—categorizing packets from "known, trusted sources," "suspect sources," and "unsure sources"—was inherently taught by Connor’s disclosure of sorting based on "packet property," which a person of ordinary skill in the art (POSITA) would understand includes the packet's source address.
  • To the extent Connor was viewed as not explicitly teaching the three source-based categories, Petitioner asserted it would have been obvious to modify Connor in view of Schuba. Schuba explicitly teaches a method for protecting against DoS attacks by classifying packet sources as "acceptable," "unacceptable," or "suspect," which directly corresponds to the categories claimed in the ’046 patent.
  • Petitioner further argued for combining Connor with Maher. Maher teaches a system that reduces processing latency by sending only a portion of packets requiring special handling to the CPU. A POSITA would have been motivated to incorporate this teaching into Connor's system to improve efficiency. Dependent claims 2-11 were mapped to more specific disclosures within Connor, such as its teaching of high, medium, and low priority queues and its operation on the Internet.
  • Motivation to Combine (for §103 grounds): Petitioner asserted a POSITA would combine Connor with Schuba to enhance the security of Connor’s priority-based processing system. This would be achieved by incorporating Schuba’s well-defined, source-based security classifications to prevent known DoS vulnerabilities, a primary concern in network management. The motivation to combine Connor with Maher was to improve packet processing latency—a recognized goal in the art—by adopting Maher's teaching of selectively forwarding only certain packets to the CPU, thereby freeing up CPU resources for other tasks and increasing overall throughput.
  • Expectation of Success (for §103 grounds): A POSITA would have had a reasonable expectation of success in these combinations. Integrating Schuba’s source-based classification logic into Connor's queuing architecture was presented as a straightforward application of known security principles to a known routing system to achieve the predictable result of a more secure and efficient router.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial of institution under 35 U.S.C. §325(d) or §314(a) would be inappropriate. The petition asserted that the General Plastic and Becton Dickinson factors strongly favor institution.
• Petitioner contended that it is not a serial petitioner, as this is its first IPR challenge against the ’046 patent. The petition was filed in direct response to the Patent Owner’s own "serial litigation strategy" of asserting the patent against numerous defendants over several years.
• Crucially, Petitioner argued the invalidity grounds are not cumulative to art previously considered. The primary references, Connor and Maher, were not before the USPTO during original prosecution or considered in a previously instituted IPR filed by a different party (Juniper Networks). While Schuba was raised in the Juniper IPR, its combination with Connor and Maher presented here is new. Petitioner asserted these new combinations and arguments warrant a review on the merits.

5. Relief Requested

• Petitioner requests that the Board institute an inter partes review of claims 1-11 of Patent 7,103,046 and cancel those claims as unpatentable under 35 U.S.C. §103.