PTAB correctly found all re-examined claims of computer storage patents were obvious


June 06, 2017

The Patent Trial and Appeal Board did not err in finding following inter partes review that all claims of three computer storage patents owned by Crossroads Systems were unpatentable as obvious, according to the U.S. Court of Appeals for the Federal Circuit (Crossroad Systems, Inc. v. Oracle Corp., June 6, 2017, Reyna, J.). The court concurrently issued a second decision, affirming two additional Board decisions invalidating as obvious the challenged claims of one of the patents for the same reasons articulated in the first decision.

Crossroads owns U.S. Patent Nos. 6,425,035, 7,934,041, and 7,051,147, all of which are family members entitled "Storage router and method for providing virtual local storage." The patents teach a system for providing network-based computer storage. A storage router sits in between workstations and storage devices, mapping workstations to portions of storage devices. Fibre Channel/Small Computer System Interface ("SCSI") protocols, standard protocols used in network-attached storage systems, are used to connect the workstations to the storage router and the storage router to the storage devices. The Board instituted inter partes review of all three patents.

The primary disqualifying prior art reference at issue was the CMD Technology, Inc., CRD-5500 SCSI RAID Controller User’s Manual. The Manual describes a Redundant Array of Independent Disks ("RAID") controller which connects numerous redundant disk drives to one or more host. The Board found all claims of the three patents at issue are obvious over a combination of the CRD-5500 Manual and three secondary references: HP JournalFibre Channel Standard, and QLogic Data Sheet.

"Maps between devices" limitation. On appeal, Crossroads argued that the Board’s interpretation of the "maps between devices" limitation found in all claims of the patents was erroneous. According to Crossroads, the CRD-5500 Manual maps storage devices to one of four numbered channels, not host devices, and no reasonable construction of "maps between devices" could include channel-oriented mapping.

Applying the broadest reasonable interpretation, the court agreed with the Board that a map between storage devices and hosts, where each host is represented by a unique channel number, can still be a "map between devices." In the CRD-5500 Manual, a host and a channel number are functionally the same thing, the court noted. Every implementation of the CRD-5500 depicted in the Manual gives each host device its own "host channel," and the channel number uniquely identifies the host. The Board correctly found that the channel number is merely an intermediate identifier for a host device, and that the ultimate logical mapping performed by the CRD-5500 is from a storage device to a host. Accordingly, the Board did not err in concluding that the Manual discloses maps between devices as claimed by the Crossroads’ patents.

Other limitations. Crossroads additionally challenged the Board’s obviousness findings for three limitations found in three dependent claims. Crossroads contended that the "unique identifier," "world wide name," and "host device ID" claim limitations are not disclosed by the CRD-5500 Manual. According to Crossroads, these limitations expressly require that the map identify connected devices using specific technologies and not some intermediary part of the system like a channel.

The Federal Circuit disagreed. Contrary to Crossroads’ argument, the Manual explicitly teaches device-to-device mapping: "By using the controller’s Host LUN Mapping feature, you can assign redundancy groups to a particular host." Because each host has a separate channel number that can be used to communicate with that particular host, that channel number uniquely identifies that host, the court reasoned. The Board also noted that "unique identifiers" were disclosed by the HP Journal prior art reference.

The court found that the same reasoning applied to "host device ID." The Board found that the channel numbers in the CRD-5500 manual are host device IDs. The Manual explicitly discloses using a channel number to make specific host devices to specific storage devices: "By using the controller’s Host LUN Mapping feature, you can assign redundancy groups to a particular host." Because each host device has a separate channel number that can be used to identify a particular host, device, that channel number is a host device ID.

Lastly, the Board correctly found that the "world wide name" limitation is taught by the combination of the CRD-5500 Manual, the HP Journal reference, and the Fibre Channel standard. Given the Fibre Channel standard’s disclosure of replacing simple channel numbers with world wide names in heterogeneous systems, like the CRD-5500 Manual and the HP Journal, a person of ordinary skill in the art would have thought to replace the channel numbers in the CRD-5500 system with world wide names as well, in the court’s view.

The case is Nos. 2016-2017, 2016-2026, and 2016-2027 and 2016-1930 and 2016-1931.

Attorneys: John A. Dragseth and Robert P. Courtney (Fish & Richardson PC) for Crossroads Systems, Inc. Andrew S. Ehmke (Haynes & Boone, LLP) and Jared Bobrow (Weil, Gotshal & Manges LLP) for Cisco Systems, Inc., Quantum Corp. and Oracle Corp.

Companies: Crossroads Systems, Inc.; Cisco Systems, Inc.; Quantum Corp.; Oracle Corp.

MainStory: TopStory Patent TechnologyInternet FedCirNews

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