PTAB

IPR2025-00429

Cisco Systems Inc v. WSOU Investments LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Methods and Systems of Adjusting Bandwidth Allocation
  • Brief Description: The ’884 patent relates to methods and systems for adjusting bandwidth allocation in a network. The technology involves a network element monitoring a data flow at a target port, determining both a current and a "fair-share" bandwidth allocation for that port, and adjusting the current allocation based on the calculated fair-share value, which is a proportional share of the network element's total bandwidth.

3. Grounds for Unpatentability

Ground 1: Obviousness over Feroz and Riddle - Claims 1 and 17 are obvious over Feroz in view of Riddle.

  • Prior Art Relied Upon: Feroz (Patent 7,453,804) and Riddle (Patent 7,406,522).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Feroz’s "application traffic management device" disclosed the claimed "network switching element." This device monitors data flows traversing its network interfaces (the "target port") by maintaining per-flow statistics like packet counts and current data rates, which taught the claimed "monitoring" limitation. Petitioner asserted that Feroz’s calculation of a "per-flow bandwidth allocation" or "target rate" met the limitation of determining a currently allocated bandwidth. Furthermore, Feroz’s use of a partition-based scheme to compute "weighted, fair share" bandwidth allocations taught the "determining a fair-share bandwidth allocation" limitation. This fair share was calculated as a proportion of a parent partition's total bandwidth, meeting the "proportional allocation" requirement. Finally, Feroz’s system adjusted these target rates by reallocating unused bandwidth based on the fair share calculation, satisfying the "adjusting" limitation.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the references because Feroz expressly incorporated Riddle by reference. Riddle provided additional detail on implementing bandwidth partitions, such as creating separate partitions for inbound and outbound traffic. This approach was described as a sensible and known technique for managing traffic on full-duplex interfaces (e.g., Ethernet), which Feroz’s device employed.
    • Expectation of Success: Petitioner contended that a POSITA would have a high expectation of success in the combination. The express incorporation by reference and the application of Riddle's well-understood partitioning methods to Feroz's traffic management system would yield predictable improvements in bandwidth control.

Ground 2: Obviousness over Petersen and Palacharla - Claims 1 and 17 are obvious over Petersen in view of Palacharla.

  • Prior Art Relied Upon: Petersen (Application # 2007/0248009) and Palacharla (Application # 2009/0097495).

  • Core Argument for this Ground: This ground was presented as an alternative argument, particularly if the claims were construed to cover bandwidth allocation within a single network device.

    • Prior Art Mapping: Petitioner argued Petersen's "network switching system" taught the claimed "network switching element," with its egress ports serving as the "target port." Petersen disclosed monitoring data flows by identifying packets for a specific destination, placing them into a dedicated virtual output queue (VOQ), and monitoring the queue’s status. Petitioner contended that Petersen taught determining a fair-share allocation by describing a method to divide a shared resource's capacity into a "fair portion" (e.g., 1/Nth) for each of N competing queues. This 1/Nth share was inherently a "proportional allocation" of the total bandwidth of the shared resource. Petersen’s system then "adjusted" the transmission rate for each queue to match its determined fair-share allocation.
    • Motivation to Combine: A POSITA implementing Petersen’s high-level description of VOQs would be motivated to consult Palacharla for more detailed implementation guidance. Palacharla taught using per-flow queues, a prevalent and well-known technique in the industry to solve the problem of head-of-line blocking, an issue Petersen also recognized. The combination involved the simple substitution of a known, memory-efficient queuing technique (Palacharla) into a compatible system (Petersen) to achieve the predictable benefit of non-blocking, per-flow traffic management.
    • Expectation of Success: Petitioner asserted a POSITA would have a reasonable expectation of success because Petersen's system was described as flexible regarding its queue organization. Implementing Palacharla's common per-flow queuing technique was a straightforward application of a known solution to a known problem.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge against claims 1 and 17 based on Petersen alone but relied on similar arguments for how Petersen’s fair portioning scheme met the claim limitations.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under 35 U.S.C. §325(d) was inappropriate because the prior art references asserted in the petition (Feroz, Riddle, Petersen, Palacharla) were not considered by the USPTO during the original prosecution of the ’884 patent.
  • Petitioner also argued against discretionary denial under Fintiv. Key arguments included that the parallel district court litigation was in its very early stages, with significant events like the Markman hearing scheduled after the Board’s institution decision. Petitioner further noted that the estimated trial date is proximate to the deadline for a Final Written Decision. To eliminate any overlap of issues, Petitioner stipulated that if the IPR is instituted, it will not pursue the same invalidity grounds in the district court litigation. Finally, Petitioner asserted the petition presents compelling evidence of unpatentability based on prior art not previously considered, which weighs strongly in favor of institution.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1 and 17 of Patent 9,450,884 as unpatentable.