PTAB

IPR2018-01644

Juniper Networks Inc v. Parity Networks LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: System for Fabric Packet Control
  • Brief Description: The ’963 patent discloses systems and methods for managing data traffic in a fabric network to avoid back-ups. The invention uses a managed queuing system at each switching element to monitor queue fullness and proactively discard incoming data based on preset thresholds, eliminating the need for upstream flow control messaging.

3. Grounds for Unpatentability

Ground 1: Obviousness over Schwartz and Muller - Claims 1-3 are obvious over Schwartz in view of Muller.

  • Prior Art Relied Upon: Schwartz (WO 00/02347) and Muller (WO 00/52882).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Schwartz, which relates to switching packets in a digital data network, taught most limitations of the challenged claims. Schwartz disclosed a switching node with internally coupled ports, a managed queuing system for outgoing traffic, monitoring queue quantity against a preset threshold, and discarding all data when a queue is full. However, Petitioner contended Schwartz did not explicitly teach beginning to discard data at a "preset constant rate" when a threshold is reached, or "increasing the rate of discarding" as the queue fills further. These missing elements, Petitioner asserted, were expressly disclosed by Muller. Muller taught an apparatus for early random discard of packets, describing a programmable probability indicator to randomly discard packets based on queue fullness, including using different discard probabilities for different queue regions, thereby increasing the discard rate as congestion worsens.
    • Motivation to Combine (for §103 grounds): Petitioner argued a POSITA would combine Schwartz and Muller because both references addressed the same fundamental problem of managing packet congestion in network switching nodes. A POSITA seeking to improve the congestion management system of Schwartz would have looked to known techniques like those in Muller to implement a more granular, proactive packet-dropping scheme before a queue becomes completely full.
    • Expectation of Success (for §103 grounds): A POSITA would have had a reasonable expectation of success in integrating Muller's probabilistic packet discard mechanism into Schwartz’s switching node architecture, as it involved applying a known congestion control technique to a known network element to achieve the predictable result of improved traffic management.

Ground 2: Obviousness over Firoiu and Muller - Claims 1-3 are obvious over Firoiu in view of Muller.

  • Prior Art Relied Upon: Firoiu (Canadian Application # 2310531) and Muller (WO 00/52882).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Firoiu, which related to queue management at a network node, disclosed the foundational elements of the claims. Firoiu taught a node congestion control module that manages a queue by monitoring the average queue size against thresholds and determining a drop probability. Petitioner argued Firoiu disclosed establishing a managed queue, monitoring the quantity of queued data against a threshold, and discarding all data when the queue is full (i.e., when the drop rate reaches 100%). As in Ground 1, Petitioner relied on Muller to supply the specific limitations of beginning to discard data at a "preset constant rate" and "increasing the rate of discarding" as the queue fills.
    • Motivation to Combine (for §103 grounds): Petitioner argued that Firoiu and Muller addressed the identical problem of queue management and congestion control in a network. A POSITA implementing Firoiu's congestion control system would have been motivated to incorporate the specific, programmable packet-dropping schemes from Muller to achieve a more refined control over traffic. The high degree of similarity in the problems and solutions addressed by both references would have prompted their combination.
    • Expectation of Success (for §103 grounds): Combining Muller’s random discard techniques with Firoiu’s queue management framework was presented as a straightforward application of known methods. A POSITA would have expected this combination to predictably yield a system with enhanced congestion avoidance capabilities.

4. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 1-3 of the ’963 patent as unpatentable.