Cisco Systems Inc v. Orckit Corp

1. Case Identification

• Case #: IPR2023-00402
• Patent #: 8,830,821
• Filed: January 9, 2023
• Petitioner(s): Cisco Systems, Inc.
• Patent Owner(s): May Patents Ltd.
• Challenged Claims: 1-20

2. Patent Overview

• Title: System and Method for Selecting Network Transport Entities
• Brief Description: The ’821 patent discloses a system and method for selecting and managing pairs of Multiprotocol Label Switching (MPLS) network transport entities between two endpoints. The system selects a “working entity” and a “protection entity” pair to minimize an overall cost and provide protection against network failures, and reselects the pair when certain network events occur.

3. Grounds for Unpatentability

Ground 1: Claims 1-7, 9-11, 13, and 17-20 are obvious over Doshi in view of Guichard

• Prior Art Relied Upon: Doshi (Application # 2004/0205239) and Guichard (a 2005 textbook titled "Definitive MPLS Network Designs").
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Doshi taught the core limitations of the independent claims, including selecting a pair of network paths (a primary and a restoration Label Switched Path, or LSP) from a plurality of candidate pairs in an MPLS network. Doshi’s selection method determined an overall cost for each pair—considering factors like link utilization and path disjointedness—and selected the pair with the "overall-minimal cost." This mapped to the ’821 patent’s steps of determining an overall cost and selecting an entity pair based on that cost.
  • Motivation to Combine: Doshi focused on an initial, optimized selection of an LSP pair. Guichard taught that network conditions change over time and that it is "highly desirable" to reoptimize LSP selections when a better path becomes available. Guichard disclosed event-driven triggers for this reoptimization, such as a link being restored, a new link being added, or new LSPs being set up or torn down. Petitioner contended a Person of Ordinary Skill in the Art (POSITA) would combine Guichard’s dynamic reoptimization teachings with Doshi’s cost-based selection method to ensure the selected path remains optimal throughout the network’s lifecycle. This combination allegedly rendered obvious the ’821 patent’s limitation of reselecting an entity pair upon a reselection event.
  • Expectation of Success: A POSITA would have a reasonable expectation of success because both references address path selection in MPLS networks. The combination represented applying a known technique (reoptimization) to improve a similar system (Doshi's path selection) for the predictable result of ongoing optimization.

Ground 2: Claims 8 and 12 are obvious over Doshi in view of Guichard and Huang

• Prior Art Relied Upon: Doshi (Application # 2004/0205239), Guichard (2005 textbook), and Huang (Application # 2003/0117950).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the combination in Ground 1 to address claims 8 and 12, which required configuring the working entity as "revertive." After a failure causes a switch to the protection path, revertive switching automatically returns traffic to the working path once the failure is cleared. Huang explicitly taught this "revertive switching" feature for MPLS networks.
  • Motivation to Combine: Petitioner argued that Doshi described switching from a working LSP to a protection LSP upon failure. A POSITA would be motivated to incorporate Huang’s revertive switching to improve the efficiency of Doshi’s system. When a working path is quickly restored, reverting automatically would avoid the need for the network manager to perform a full cost recalculation and reselection process just to arrive at the same, original working path. This would obviate unnecessary computations and provide a more efficient restoration process.
  • Expectation of Success: The combination involved applying a known, well-documented technique (revertive switching) to an existing MPLS failover system to achieve the predictable benefit of increased operational efficiency.

Ground 3: Claims 14-16 are obvious over Doshi in view of Guichard and Xu

• Prior Art Relied Upon: Doshi (Application # 2004/0205239), Guichard (2005 textbook), and Xu (Application # 2011/0141877).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the combination in Ground 1 to address system claims 14-16, which required logic for determining a "probability of concurrent failure" of the working and protection entities. Doshi taught selecting "strictly disjoint" paths to minimize the chance of concurrent failure, recognizing that a single failure should not affect both paths. Xu taught a more advanced method of modeling various network failure states and determining a "predetermined probability of occurrence" for each state to inform path selection.
  • Motivation to Combine: Doshi acknowledged that in some cases, strictly disjoint paths may not exist, forcing the selection of a partially disjoint pair. In such scenarios, a POSITA would be motivated to apply Xu’s probability analysis to refine the selection. By determining the probability of failure for the shared network elements, the system could select the partially disjoint pair with the lowest overall probability of concurrent failure, thereby improving reliability beyond what Doshi’s simpler disjointedness analysis could provide.
  • Expectation of Success: A POSITA would expect success in applying Xu's known probability determination techniques to Doshi's path selection method, as both operate in the same field. This would predictably improve the system's reliability, especially in complex network topologies where fully disjoint paths are unavailable.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under the Fintiv factors would be inappropriate. The co-pending district court litigation was in its very early stages, with minimal investment from the parties and no significant events like claim construction or expert discovery having occurred. Petitioner asserted that the projected trial date in the parallel proceeding, based on median time-to-trial statistics, was after the statutory deadline for the Board's Final Written Decision (FWD). Furthermore, Petitioner contended that the strong merits of the petition weighed in favor of institution. Petitioner also argued that denial under §325(d) was improper because the prior art references were not considered during the original prosecution.

5. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-20 of the ’821 patent as unpatentable.