PTAB

IPR2014-01226

Cisco Systems Inc v. Crossroads Systems Inc

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Petition
petition Intelligence

1. Case Identification

2. Patent Overview

  • Title: Storage Router and Method for Providing Virtual Local Storage
  • Brief Description: The ’035 patent describes a storage router that functions as a bridge between workstations on a first transport medium (e.g., Fibre Channel) and remote storage devices on a second transport medium (e.g., SCSI). The router uses mapping tables to provide workstations with "virtual local storage" by allocating specific partitions of the remote storage and controlling access based on those maps.

3. Grounds for Unpatentability

Ground 1: Obviousness over CRD-5500 Manual and HP Journal - Claims 1-5 and 7-14 are obvious over the CRD-5500 Manual in view of the HP Journal.

  • Prior Art Relied Upon: CRD-5500 Manual (a 1996 user's manual for a SCSI RAID Controller) and HP Journal (an October 1996 journal issue describing Fibre Channel technology).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the CRD-5500 Manual disclosed a modular storage controller that performed the core functions recited in the independent claims. Specifically, its "Host LUN Mapping" feature taught mapping hosts to specific storage subsets ("redundancy groups") and using this map to implement access controls, thereby providing virtualized storage. The controller routed data between hosts on one side and storage on the other using a native low-level block protocol (SCSI). The HP Journal taught the use of a Fibre Channel serial transport medium for connecting to hosts, a key element of the claimed invention not explicitly present in the CRD-5500's default configuration.
    • Motivation to Combine: Petitioner contended that a person of ordinary skill in the art (POSITA) would have been motivated to replace the CRD-5500's host-side SCSI interface with a Fibre Channel interface as taught by the HP Journal. The motivation was strong and explicit: the CRD-5500 Manual itself stated the controller was "designed to support tomorrow's high speed serial interfaces, such as Fiberchannel." Concurrently, the HP Journal detailed the known performance limitations of SCSI (e.g., distance, bandwidth) and extolled the clear advantages of Fibre Channel, describing it as a replacement for SCSI.
    • Expectation of Success: A POSITA would have had a high expectation of success. The CRD-5500's modular design with replaceable I/O cards was intended for such upgrades. Furthermore, the HP Journal taught that Fibre Channel was designed to be backward-compatible with existing SCSI hardware by encapsulating SCSI commands within Fibre Channel frames, ensuring the underlying storage system would function as intended after the interface upgrade.

Ground 2: Obviousness over CRD-5500 Manual, HP Journal, and QLogic Data Sheet - Claim 6 is obvious over the CRD-5500 Manual in view of the HP Journal and in further view of the QLogic Data Sheet.

  • Prior Art Relied Upon: CRD-5500 Manual, HP Journal, and QLogic Data Sheet (a 1996 data sheet for the family of SCSI processors used in the CRD-5500 controller).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground specifically addressed dependent claim 6, which recites details of the "second controller" (the controller interfacing with the storage devices). While the CRD-5500 Manual disclosed this controller as a SCSI I/O module, Petitioner asserted that a POSITA would look to the component's own documentation for its internal structure. The QLogic Data Sheet, which described the processors known to be used in the CRD-5500's I/O modules, explicitly disclosed the additional limitations of claim 6: a "second protocol unit" (SCSI transceivers), an "internal buffer" (a FIFO buffer), and a "direct memory access (DMA) interface."
    • Motivation to Combine: The motivation to combine the QLogic Data Sheet was straightforward. A POSITA, knowing that the CRD-5500 controller used QLogic SCSI processors in its I/O modules, would naturally consult the QLogic Data Sheet to understand the components' functionality and internal architecture. This was not an inventive leap but a routine step in designing with or analyzing off-the-shelf components.

4. Key Claim Construction Positions

  • "to map between devices...": Petitioner argued for a construction of "to allocate storage on the storage devices to devices on the first transport medium to facilitate routing and access controls." This construction aligned with the specification’s description of using mapping tables and was central to showing that the CRD-5500 Manual's "Host LUN Mapping" feature met this limitation.
  • "native low level block protocol": Petitioner proposed construing this term as "a protocol in which storage space is accessed at the block level, such as the SCSI protocol." This was consistent with the patent’s own example of a SCSI command and the protocol used by the primary prior art reference.
  • "remote": Petitioner argued for "indirectly connected through a storage router to enable connections to storage devices at a distance greater than allowed by a conventional parallel network interconnect." This construction was important to demonstrate how the combination of the CRD-5500 controller (indirect connection) with Fibre Channel (greater distance), as taught by the HP Journal, met the claim language.

5. Relief Requested

  • Petitioner requested institution of an inter partes review (IPR) and cancellation of claims 1-14 of Patent 6,425,035 as unpatentable.