PTAB

IPR2015-01731

IBM Corp v. Parallel Networks Licensing LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: System and Method for Managing Dynamic Web Page Generation Requests by Intercepting Request at Web Server and Routing to Page Server Thereby Releasing Web Server to Process Other Requests
  • Brief Description: The ’554 patent describes a partitioned server architecture for managing dynamic web page requests. The system routes incoming requests from a primary web server to one of multiple page servers for processing, which frees the web server to handle other incoming requests, thereby improving performance and scalability.

3. Grounds for Unpatentability

Ground 1: Anticipation over SWEB 95 - Claims 12, 20-31, and 35-45 are anticipated by SWEB 95

  • Prior Art Relied Upon: SWEB 95 (Andresen et al., “SWEB: Towards a Scalable World Wide Web Server on Multicomputers,” Sept. 1995).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that SWEB 95, a publication describing a scalable web server architecture, disclosed every limitation of the challenged independent claims 12 and 20. The SWEB 95 system was designed to address the bottleneck of single-server web implementations by using a cluster of workstations. Petitioner asserted that SWEB 95 disclosed a method for managing dynamic web page requests where an initial server (a "Web server") receives a request. This server then uses a "distributed scheduler" (a "dispatcher") to determine the optimal server in the cluster (a "page server") to handle the request based on dynamic load information. The request is then routed to the selected page server, which processes the request and can dynamically generate a web page using CGI programs. This routing action inherently releases the initial web server to process other requests, a core element of the claims. The selection process in SWEB 95 involves examining the request and dynamic system load, and the subsequent routing satisfies the "dispatching" limitations.

Ground 2: Obviousness over SWEB 95 and Leaf - Claims 33 and 47 are obvious over SWEB 95 in view of Leaf

  • Prior Art Relied Upon: SWEB 95 (a 1995 technical report) and Leaf (Patent 5,754,772).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addressed limitations in dependent claims 33 and 47 requiring the generated web page to be received back at the initial web server and then provided to the original requestor. Petitioner argued that while SWEB 95 taught redirecting the client to the selected page server, Leaf disclosed a hierarchical server architecture where a front-end server routes requests to back-end transaction servers. In Leaf, the back-end server processes the request, formats the data into an HTML document, and forwards it back to the front-end server, which then sends the final page to the requesting browser.
    • Motivation to Combine: Petitioner contended a person of ordinary skill in the art (POSITA) would have been motivated to combine Leaf's centralized response architecture with SWEB 95's distributed load-balancing system. Both references addressed the common problem of efficiently handling web requests. A POSITA would have recognized that using the initial SWEB 95 server as a gateway, as taught by Leaf, would solve an inefficiency in SWEB 95's client-side redirection method, namely the overhead of an additional connect/respond cycle. This combination would centralize client interaction while retaining the benefits of back-end load balancing.
    • Expectation of Success: The combination involved applying a known networking technique (a gateway server model) to a known system (a distributed server cluster) to achieve a predictable improvement in efficiency.

Ground 3: Obviousness over SWEB 95 and Bradley - Claims 29, 43, and 49 are obvious over SWEB 95 in view of Bradley

  • Prior Art Relied Upon: SWEB 95 (a 1995 technical report) and Bradley (a 1995 publication on a web-based anatomy atlas).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addressed limitations requiring the server selection to be based on whether a requested web page is cached (claims 29 and 43) and the storing of a dynamically generated page for later retrieval (claim 49). Petitioner asserted that Bradley disclosed a web server using CGI programs to convert image files on-demand and, critically, caching the dynamically generated output files to improve performance. When a request was received, Bradley’s server would first check the cache.
    • Motivation to Combine: A POSITA would have been motivated to incorporate Bradley's caching functionality into the SWEB 95 system for the known and predictable benefit of improved performance. SWEB 95 already disclosed a sophisticated scheduler that considered factors like CPU load and file location to select the best server. It would have been obvious to a POSITA to add another data point to this selection logic: whether the requested content was already generated and cached on a particular server, as taught by Bradley. This would avoid the computational cost of regenerating content, a well-understood goal in the art.
    • Expectation of Success: Implementing caching was a well-known technique for accelerating server performance. A POSITA would have had a high expectation of success in modifying SWEB 95’s selection algorithm to consider cache status to reduce request-response times.
  • Additional Grounds: Petitioner also asserted that claims 12, 20-31, 33, 35-45, 47, and 49 are obvious over SWEB 95 alone. These arguments posited that to the extent any claim element was not explicitly disclosed in SWEB 95, its inclusion would have been an obvious design choice representing the application of a known technique for its known purpose.

4. Key Claim Construction Positions

  • "releasing said Web server to process other requests": Petitioner argued for a broad interpretation of "freeing said Web server to process other requests." This construction, supported by the specification and Federal Circuit precedent in related litigation, meant that the limitation is met when processing a request on a page server makes any of the web server’s hardware resources (e.g., CPU cycles, memory) available for other uses, including processing another web page request.
  • "dispatching": Petitioner proposed this term be construed as "transferring processing responsibility." This interpretation was based on the specification's use of "handing off" to describe the action. This construction covers transferring a request to a separate machine or simply to another software process or thread on the same machine.
  • "intercepting said request at said Web server": Petitioner argued this means "to stop or interrupt the handling of said request at the Web server." The petition asserted that based on the patent's disclosure, this interception occurs after the web server first receives the request but before it fully processes it, thereby diverting it to the dispatching mechanism.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 12, 20-31, 33, 35-45, 47, and 49 of the ’554 patent as unpatentable.