Hewlett Packard Enterprises Co v. Parity Networks LLC

1. Case Identification

• Case #: IPR2019-00433
• Patent #: 6,870,844
• Filed: December 13, 2018
• Petitioner(s): Hewlett Packard Enterprise Company
• Patent Owner(s): Parity Networks, LLC
• Challenged Claims: 1, 2, 6, 7, 10, 15, 19-23

2. Patent Overview

• Title: Multicast-Capable Port and Data Router
• Brief Description: The ’844 patent discloses a multicast-capable port within a network switching fabric card. The port is characterized by diverting data packets assigned for multicasting from an egress path to a multicast-capable component for replication and/or re-addressing, and then outputting the resulting packets to an ingress path back into the port.

3. Grounds for Unpatentability

Ground 1: Obviousness over Rose, Lipp, and Barnett - Claims 1, 2, 6, 7, 10, 15, 19-23 are obvious over Rose in view of Lipp and Barnett.

• Prior Art Relied Upon: Rose (Patent 7,103,039), Lipp (Patent 6,751,219), and Barnett (Patent 5,436,893).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Rose taught the foundational system: a fabric card in a data router with multiple bidirectional ports within a switching fabric. However, Rose did not provide specific implementation details for multicasting. Petitioner asserted that Lipp supplied the missing multicasting method, teaching a "drop-and-continue" technique where a multicast packet is replicated at a first egress port, with one copy sent out of the port and the other "re-inserted" back into the switch fabric to travel to the next egress port. To provide the specific port structure for implementing Lipp’s method, Petitioner pointed to Barnett. Barnett taught a link controller for a switch fabric port, including a dedicated processing engine and recirculate FIFOs, that permits a multicast cell arriving from the switch fabric to be copied and re-presented to the processor for retransmission, thus performing the replication function required by Lipp. The combination of Barnett's port structure with Lipp's replication method, implemented in Rose's general switching fabric, allegedly rendered the limitations of independent claims 1, 10, and 15 obvious.
  • Motivation to Combine: A POSITA, starting with Rose’s switching network, would be motivated to implement a specific multicasting technique to improve its functionality. Lipp, which disclosed multicasting in an analogous mesh-based switch fabric, provided a known solution. To implement Lipp’s replication function at the port level, a POSITA would look for known port structures capable of such functionality. Barnett taught a suitable port implementation with a link controller specifically designed for multicast switching, making it a natural and predictable component to integrate.
  • Expectation of Success: A POSITA would have a reasonable expectation of success because all three references operated in the same field of multicast switching, taught analogous switch fabric structures, and their teachings were complementary. Integrating Barnett’s known port controller to perform Lipp’s replication method within Rose’s standard switch architecture was presented as a routine design choice.

Ground 2: Obviousness over Admitted Prior Art, Lipp, and Barnett - Claims 1, 2, 6, 7, 10, 15, 19-23 are obvious over the ’844 patent’s Admitted Prior Art (APA) in view of Lipp and Barnett.

• Prior Art Relied Upon: The ’844 patent's Admitted Prior Art (APA), Lipp (Patent 6,751,219), and Barnett (Patent 5,436,893).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground replaced Rose with the patent owner’s own admissions in the ’844 patent specification. Petitioner argued the APA described the same foundational system as Rose, admitting that the prior art included routers with switching fabrics comprising interconnected fabric cards with multiple ports. The APA also acknowledged that multicasting, including the spawning of multiple packet copies, was well-known and performed by data routers. As with Rose, the APA lacked specific implementation details for multicast replication at the port level. Petitioner contended that Lipp and Barnett would be combined with the APA for the same reasons they would be combined with Rose.
  • Motivation to Combine: The motivation was identical to Ground 1. A POSITA starting with the conventional router described in the APA would seek to implement a known, specific multicasting method. Lipp provided this method, and Barnett provided the well-understood port structure to achieve it.
  • Expectation of Success: The expectation of success was similarly high, as the combination involved integrating known, compatible components (Lipp’s method and Barnett’s port) into the admitted prior art system to achieve the predictable result of efficient multicasting.

• Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 3) based on Tout (Patent 5,991,295) in view of Lipp and Barnett. This ground relied on a similar combination theory, with Tout providing an alternative base ATM switch with a switch fabric card.

4. Key Claim Construction Positions

• "into the port" / "out of the port": Petitioner argued that these phrases, appearing in claims 1 and 15, should be construed to mean "through the port." This construction was based on arguments made during prosecution of the ’844 patent, where the applicant distinguished a prior art reference (Takahashi) by explicitly stating that the claimed ingress and egress paths were paths through the port, not simply to or from the port. Petitioner asserted this amounted to a clear and unmistakable disavowal of claim scope, mandating the narrower "through the port" construction.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. § 325(d) would be inappropriate. It contended that none of the primary prior art references relied upon in the petition (Rose, Lipp, Barnett, and Tout) were cited or considered by the Examiner during the original prosecution of the ’844 patent. Therefore, the Patent Office had not previously considered these grounds or substantially similar ones.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1, 2, 6, 7, 10, 15, and 19-23 of the ’844 patent as unpatentable under 35 U.S.C. §103.