Arista Networks Inc v. Corrigent Corp

1. Case Identification

• Case #: IPR2023-00839
• Patent #: 9,118,602
• Filed: April 18, 2023
• Petitioner(s): Arista Networks, Inc.
• Patent Owner(s): Corrigent Corporation
• Challenged Claims: 1-26

2. Patent Overview

• Title: Methods for Link Aggregation in MPLS Networks
• Brief Description: The ’602 patent discloses methods and systems for assigning and utilizing an Ethernet physical data port within a Link Aggregation Group (LAG) in a Multi-Protocol Label Switching (MPLS) network. The technology addresses the distribution of traffic across a group of parallel physical links that are joined together to function as a single logical link.

3. Grounds for Unpatentability

Ground 1: Claims 1-26 are obvious over RFC 3209 in view of Raz.

• Prior Art Relied Upon: RFC 3209 (a 2001 Internet standards document) and Raz (Patent 7,466,697).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that RFC 3209 teaches the foundational method of establishing label-switched paths (LSPs) in an MPLS network using Resource Reservation Protocol (RSVP) signaling. This includes a network node (a switch or router) assigning an outgoing physical interface to a network tunnel (LSP) and creating a label to identify traffic for that tunnel. Petitioner asserted that Raz teaches specific, performance-enhancing techniques that were obvious to apply to RFC 3209’s general framework. Specifically, Raz discloses using a LAG composed of multiple physical subports (e.g., Ethernet ports) to handle high-speed traffic within an MPLS switch. Raz further teaches assigning a single subport to an LSP based on bandwidth requirements and encoding a serial number for that specific subport into the MPLS data packet label. This encoded label allows the switch to efficiently route incoming packets to the correct subport.
  • Motivation to Combine: Petitioner contended a person of ordinary skill in the art (POSITA) would combine these references to improve the performance and traffic engineering capabilities of the MPLS network described in RFC 3209. Both references address the same problem of allocating bandwidth and resources for LSPs. Raz’s method of using aggregated links and subport-specific labels is a well-known technique to handle the high-speed connections and bandwidth demands common in such networks. Furthermore, Raz explicitly states its functionality is compatible with RSVP-TE signaling, the exact protocol detailed in RFC 3209, providing a direct suggestion to combine.
  • Expectation of Success: A POSITA would have had a high expectation of success because combining the references involved applying Raz's specific implementation of LAGs and subport labeling to the standardized RSVP-TE framework of RFC 3209. Since Raz itself suggests this compatibility, the combination represented a predictable integration of known networking principles.

Ground 2: Claims 1-26 are obvious over RFC 3209, Raz, and Ferguson.

• Prior Art Relied Upon: RFC 3209, Raz (Patent 7,466,697), and Ferguson (Patent 7,277,386).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground builds upon the combination of RFC 3209 and Raz. Petitioner introduced Ferguson to explicitly teach that the techniques for load balancing traffic across aggregated links are applicable not only within a single network device (as taught by Raz) but also between distinct network devices, such as two switches connected by a LAG. Ferguson discloses distributing MPLS packets across an aggregated link having two or more physical interconnects between devices. This directly supports applying Raz’s intra-device subport assignment and labeling techniques to the inter-device communication paths established according to RFC 3209.
  • Motivation to Combine: A POSITA would be motivated to incorporate Ferguson’s teachings because all three references are analogous art focused on solving the same problem: ensuring sufficient bandwidth for high-speed packet streams in an MPLS network using LAGs. Ferguson provides the explicit rationale for applying the principles of intra-device traffic management (from Raz) to inter-device links. It confirms that using LAGs to connect separate switches and manage traffic across those links was a known and desirable technique, making it an obvious extension of the RFC 3209/Raz combination.
  • Expectation of Success: The combination would have been successful because Ferguson demonstrates that the techniques are readily compatible and that there is no technical barrier to applying intra-device load-balancing methods to inter-device links. This reinforces the predictability of the combination.

4. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under §314(a) and §325(d). Regarding the Fintiv factors, Petitioner asserted that the co-pending district court litigation is in its early stages with no trial date set, making an FWD likely to issue well before any trial. Petitioner contended that the PTO has not previously considered this prior art or the expert analysis presented, arguing institution would narrow issues for the district court and promote efficiency. The merits of the petition are strong, and other factors are either neutral or weigh against denial.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-26 of the ’602 patent as unpatentable.