PTAB

IPR2017-01707

Cavium Inc v. Alacritech Inc

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Petition
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1. Case Identification

2. Patent Overview

  • Title: Fast-Path Apparatus For Transmitting Data Corresponding to a TCP Connection
  • Brief Description: The ’072 patent describes methods and systems for improving network performance by offloading TCP/IP protocol processing from a host computer's main processor to an intelligent network interface card (INIC). This creates a "fast path" that bypasses the host's conventional protocol stack for established connections, thereby reducing CPU load and accelerating data transmission.

3. Grounds for Unpatentability

Ground 1: Obviousness over Erickson and Tanenbaum96 - Claims 1-21 are obvious over Erickson in view of Tanenbaum96.

  • Prior Art Relied Upon: Erickson (Patent 5,768,618) and Tanenbaum96 (A. Tanenbaum, Computer Networks, 3rd ed. (1996)).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Erickson, which describes an I/O device adapter for fast-path processing of UDP/IP packets, discloses the majority of the claimed limitations. Erickson teaches an adapter that receives pre-negotiated header templates from a host computer, stores them in its own memory, and uses them to generate packet headers, thereby offloading protocol processing. While Erickson's primary example is UDP/IP, it explicitly mentions its applicability to TCP/IP. Petitioner asserted that Tanenbaum96, a foundational networking textbook, supplies the necessary details for implementing TCP fast-path processing. Tanenbaum96 teaches using a "prototype header" (equivalent to Erickson's template) and a "connection record" (equivalent to the claimed "context") to accelerate TCP transmissions. Critically, Tanenbaum96 explicitly states that this fast-path transport entity can be located "on the network interface card." The combination, therefore, taught a POSITA to build the exact system claimed: establishing a connection context on a host, transferring header information to an interface device, and having the device segment data and prepend headers from the template to form transmit packets.
    • Motivation to Combine (for §103 grounds): Petitioner asserted multiple motivations for a person of ordinary skill in the art (POSITA) to combine the references. First, Erickson expressly directs the reader to the Tanenbaum textbook for further details on TCP, creating a direct link between the references. Second, given the rising prominence of TCP/IP for internet applications in 1996, a POSITA seeking to apply Erickson's fast-path architecture to TCP would have naturally consulted a standard, authoritative text like Tanenbaum96 to implement the TCP-specific functionality, such as segmentation and state management.
    • Expectation of Success (for §103 grounds): A POSITA would have had a high expectation of success because combining the references involved applying a well-understood protocol (TCP, as detailed in Tanenbaum96 and standard RFCs) to a suitable, existing hardware architecture (Erickson's I/O adapter). The proposed modification was not a new invention but rather the application of a known technique to a known system to achieve predictable performance improvements.

4. Key Claim Construction Positions

  • "context": Petitioner contended that while the term is likely indefinite, for the purposes of the inter partes review (IPR), its broadest reasonable construction requires, at a minimum, "data regarding an active connection." This construction was argued to be consistent with the patent owner's position in co-pending litigation and was used to show that the "connection record" taught by Tanenbaum96 met the limitation.
  • "prepending": Petitioner argued that the term should be construed to mean "adding to the front," based on an explicit definition provided in the ’072 patent specification.
  • "status information": Petitioner asserted that the ’072 patent does not define this term but that the claims imply it is information found within the template header. Citing the patent owner's infringement contentions, Petitioner noted that this term was asserted to cover "Acknowledgement and Sequence numbers," which are standard fields in a TCP header and disclosed in the prototype header of Tanenbaum96.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-21 of the ’072 patent as unpatentable under 35 U.S.C. §103.