NetApp Inc v. Crossroads Systems Inc

1. Case Identification

• Case #: IPR2015-00772
• Patent #: 7,987,311
• Filed: February 19, 2015
• Petitioner(s): NetApp Inc.
• Patent Owner(s): Crossroads Systems, Inc.
• Challenged Claims: 1-28

2. Patent Overview

• Brief Description: The ’311 patent relates to a storage router that provides host computers with virtual local storage on remote storage devices. The router uses a map to control host access to specific storage regions on the remote devices, processing requests using a native low-level block protocol.

3. Grounds for Unpatentability

Ground 1: Obviousness over CRD-5500 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 1996 RAID controller manual), CRD-5500 Data Sheet (a 1996 data sheet), and Smith (a 1996 Hewlett-Packard Journal article describing the Tachyon chip).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that the CRD-5500 references disclose a RAID controller that functions as the claimed "storage router." The controller's "Host LUN Mapping" feature provides virtual storage and serves as the claimed "map" to allocate and control host access to specific storage redundancy groups. The CRD-5500 Data Sheet discloses that the controller's architecture was designed to support high-speed serial interfaces like Fibre Channel. Smith discloses the Tachyon chip, an off-the-shelf component designed to bridge a Fibre Channel transport medium to a SCSI transport medium by encapsulating SCSI commands. The combination results in a system where the CRD-5500 controller is equipped with host interface modules using the Tachyon chip, thereby connecting to hosts via Fibre Channel (the "first transport medium") and to storage devices via SCSI (the "second transport medium"), meeting the core limitations of the challenged claims.
  • Motivation to Combine: A POSITA would combine the references because the CRD-5500 Data Sheet expressly suggested its controller was designed to support emerging high-speed interfaces like Fibre Channel. Smith provided the exact off-the-shelf component (the Tachyon chip) to implement this suggestion. The combination was motivated by the desire to leverage the high bandwidth and extended distance capabilities of Fibre Channel while utilizing the established mapping and RAID management features of the CRD-5500 controller.
  • Expectation of Success: A POSITA would have a high expectation of success, as the components were designed for this type of integration. The Tachyon chip was created to serve as a bridge, making its incorporation into the modular I/O slots of the CRD-5500 a predictable and straightforward implementation.

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 discloses a basic storage control device that connects hosts over a Fibre Channel medium to storage over a SCSI medium. Kikuchi's device performs access control using an "address registration unit" that functions as a basic map. Bergsten was argued to enhance Kikuchi's system by teaching a more sophisticated storage controller with advanced virtual storage emulation. Bergsten describes using emulation and physical drivers to manage communications and transparently map host logical addresses to physical storage addresses, allowing storage to be reconfigured without host-side involvement. Combining the references, Kikuchi provides the foundational FC-to-SCSI bridge, while Bergsten provides the detailed virtual mapping and transparent access claimed in the ’311 patent.
  • Motivation to Combine: A POSITA would combine Kikuchi and Bergsten to improve Kikuchi’s basic system with the significant advantages of Bergsten's advanced virtualization. Bergsten taught the desirability of a storage controller that was not dependent on specific hardware configurations. Adding Bergsten’s functionality to Kikuchi’s architecture would increase storage flexibility, expand the addressable storage range, and allow for easier system administration, all of which were known goals in the art.
  • Expectation of Success: Success was predictable because the underlying architectures were compatible. Both references operated in the same technical space of bridging host and storage protocols, making the integration of Bergsten's software-driven emulation features into Kikuchi's hardware a routine modification for a skilled engineer.

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 # Hei 5[1993]-181609).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground began with Bergsten's disclosure of a storage controller providing virtualized storage and protocol bridging. Petitioner contended that while Bergsten describes virtualization, it lacks detail on implementing granular access controls. Hirai remedies this by disclosing a system that uses a "partition control table" to manage specific access rights (e.g., read, write, create) for different computers to shared storage partitions. The combination incorporates Hirai's detailed, table-based access control mechanism into Bergsten's controller. This combined system first maps a host request to a logical address per Bergsten, and then verifies the access type against the permissions in Hirai's partition control table, thus meeting the claim limitations for mapping and controlling access.
  • Motivation to Combine: A POSITA would combine Bergsten and Hirai to enhance Bergsten’s virtualization system with the more robust and granular access control taught by Hirai. This would allow an administrator to assign different levels of access (e.g., read-only vs. full access) to various hosts for the same data, a highly desirable feature in a shared network storage environment.
  • Expectation of Success: The combination was a predictable integration of known concepts. Applying a known access control method (Hirai) to a virtualized storage system (Bergsten) to improve security and management was a straightforward design choice with a high expectation of success.

4. Key Claim Construction Positions

• Native low-level block protocol (NLLBP): Petitioner argued that under the broadest reasonable interpretation, this term encompasses protocols like SCSI and Fibre Channel Protocol (FCP). The key feature is the ability to exchange block-level information directly without the overhead of high-level protocols and file systems typically required by general-purpose network servers. This construction was central to asserting that the protocols used in the prior art meet the claim limitations.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. §325(d) was inappropriate. A previous petition (IPR2014-01233) was denied institution not on the merits, but due to a procedural defect where evidence was improperly incorporated by reference from an expert declaration. Petitioner asserted that the present petition corrected this defect by presenting all prior art evidence and arguments within the four corners of the document, warranting a full consideration on the merits.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-28 of the ’311 patent as unpatentable.