PTAB

IPR2014-01233

NetApp v. Crossroads Systems Inc

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petition

1. Case Identification

2. Patent Overview

  • Title: Storage Router and Method for Providing Virtual Local Storage
  • Brief Description: The ’311 patent discloses a storage router that functions as a bridge between a Fibre Channel (FC) network and a SCSI bus. The router uses native low-level block protocols (NLLBP) to manage access controls, enabling remote SCSI storage devices to appear as virtual local storage to workstations on the FC network.

3. Grounds for Unpatentability

Ground 1: Obviousness over CRD-5500 References and Smith - Claims 1-28 are obvious over the CRD-5500 User Manual and CRD-5500 Data Sheet in view of Smith.

  • Prior Art Relied Upon: CRD-5500 User Manual (a manual for a SCSI RAID controller), CRD-5500 Data Sheet (a data sheet for the same controller), and Smith (a 1996 journal article describing the Tachyon FC protocol chip).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the CRD-5500 controller, as described in its User Manual and Data Sheet, taught the core functionalities of the claimed storage router. Specifically, its "Host LUN Mapping" feature disclosed maintaining a map to allocate storage space and control access, providing virtual local storage to host devices. While the CRD-5500 was a SCSI controller, its Data Sheet explicitly stated it was designed to support high-speed serial interfaces like Fibre Channel. Smith disclosed the off-the-shelf Tachyon FC chip, which could serve as the FC interface (the claimed "first controller") for the CRD-5500. The combined system would bridge an FC transport medium to a SCSI transport medium, using NLLBP (FCP and SCSI commands) to control access via the Host LUN Mapping tables, thus meeting the limitations of independent claims 1 and 16.
    • Motivation to Combine: A POSITA would combine these references because the CRD-5500 Data Sheet expressly suggested using a high-speed serial interface like FC. Smith provided a well-known, commercially available FC protocol chip suitable for this purpose. The motivation was to upgrade the CRD-5500 controller with the FC connectivity for which it was designed, thereby increasing performance and extending the distance between hosts and storage.
    • Expectation of Success: A POSITA would have a high expectation of success in integrating the standard Tachyon FC chip (Smith) into a controller (CRD-5500) explicitly designed to support such interfaces.

Ground 2: Obviousness over Kikuchi and Bergsten - Claims 1-28 are obvious over Kikuchi in view of Bergsten.

  • Prior Art Relied Upon: Kikuchi (Patent 6,219,771) and Bergsten (Patent 6,073,209).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Kikuchi disclosed a control device that bridges multiple FC hosts to a single SCSI storage device, providing access control by checking a host address against a registration unit. This taught the basic router and access control elements. Bergsten taught a more advanced storage controller that virtualized remote storage for a host, making it appear as a local storage array through transparent virtual-to-physical address mapping. The combination would enhance Kikuchi's FC-to-SCSI bridge with Bergsten's sophisticated virtualization and transparent mapping capabilities. The resulting system would use a map (an enhanced correlation chart from Kikuchi) to allocate virtual storage (as taught by Bergsten) and control access using NLLBP over FC and SCSI channels.
    • Motivation to Combine: A POSITA would combine the teachings to improve the Kikuchi system with the significant advantages of virtualized, networked storage taught by Bergsten. Incorporating Bergsten's virtual storage emulation would increase the number of accessible storage devices and the available address range, and allow for equipment changes without host-side involvement, which were all known and desirable goals in network storage design at the time.
    • Expectation of Success: The references were argued to be highly compatible, as both operate in the FC-to-SCSI bridge environment. A POSITA could routinely implement Bergsten’s mapping logic within Kikuchi’s controller architecture.

Ground 3: Obviousness over Bergsten and Hirai - Claims 1-28 are obvious over Bergsten in view of Hirai.

  • Prior Art Relied Upon: Bergsten (Patent 6,073,209) and Hirai (JP Application Publication No. Hei 5[1993]-181609).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Bergsten provided the foundational virtualized storage controller that bridges an FC host to a SCSI disk array and makes remote storage appear local. However, Bergsten lacked a detailed disclosure of implementing granular access controls. Hirai cured this deficiency by teaching a disk controlling device that uses a "partition control table" to manage specific access rights (e.g., read, write, create, delete) for multiple computers sharing disk devices. The combination would integrate Hirai's detailed, table-based access control mechanism into Bergsten's virtualized storage controller. This would allow the controller to maintain a map that not only translates virtual addresses but also enforces specific access permissions for each host to different partitions of the storage array.
    • Motivation to Combine: A POSITA implementing Bergsten’s system would be motivated to incorporate a robust access control mechanism to manage how different hosts interact with the shared virtualized data. Hirai provided a known, table-based solution for this exact problem. Combining them would improve the security and manageability of the Bergsten system by allowing an administrator to assign varying levels of access (e.g., read-only vs. read-write) to different user groups, a clear and desirable advantage.
    • Expectation of Success: Applying the logical access control rules taught by Hirai to the logical addressing and virtualization system of Bergsten would be a predictable and straightforward design choice for a person skilled in network storage architecture.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-28 of Patent 7,987,311 as unpatentable.