PTAB

IPR2019-01289

Nokia of America Corporation v. Packet Intelligence LLC

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1. Case Identification

2. Patent Overview

  • Title: Method of and Monitor Apparatus for Analyzing a Flow of Packets
  • Brief Description: The ’751 patent discloses a method and apparatus for analyzing network packet flows to identify the associated application programs. The system monitors packets, builds a unique "signature" to identify a "conversational flow," and checks a database to determine if the packet belongs to a new or existing flow.

3. Grounds for Unpatentability

Ground 1: Anticipation/Obviousness over Riddle and Bruins - Claims 1, 2, 5, 10, 14, and 15 are anticipated by Riddle under 35 U.S.C. §102 or are obvious over Riddle in view of Bruins under 35 U.S.C. §103.

  • Prior Art Relied Upon: Riddle (Patent 6,412,000) and Bruins (Patent 6,308,148).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Riddle, which teaches a system for classifying network traffic, discloses every limitation of the challenged claims. The central dispute revolved around the term "conversational flow," which Petitioner asserted Riddle teaches through its disclosure of "service aggregates." Riddle described service aggregates as a way to group multiple, distinct connections (e.g., the command and data channels in an FTP session) that are part of a single "conversation" between a client and server into a common traffic class. Petitioner also contended that Riddle’s ability to classify PointCast traffic, which uses multiple disjointed connections, met this limitation, noting that the ’751 patent’s own provisional application characterized such traffic as a conversational flow. For other limitations, Petitioner argued Riddle’s "saved list" functions as the claimed "flow-entry database," and its process of tracking duplicate flows and byte counts meets the requirements for performing "state operations" and storing "statistical measures."
    • Motivation to Combine (for §103 grounds): To the extent Riddle’s "saved list" is not considered a formal database, Petitioner argued a POSITA would combine Riddle with Bruins. Bruins discloses using a database to store and aggregate packet flow information. Since both Riddle and Bruins address classifying network traffic, a POSITA would combine Bruins' database with Riddle's classification system to gain the predictable benefits of enhanced data functionality, such as improved searching, analysis, and simultaneous access for multiple network operators.
    • Expectation of Success: A POSITA would have a high expectation of success, as this combination represented the simple substitution of one known element (a database) for another (a list) to achieve a predictable improvement in functionality.

Ground 2: Obviousness over Riddle, Bruins, and RFC 1945 - Claims 1, 2, 5, 10, 14, and 15 are obvious over Riddle in view of Bruins and further in view of RFC 1945.

  • Prior Art Relied Upon: Riddle (Patent 6,412,000), Bruins (Patent 6,308,148), and RFC 1945 (Hypertext Transfer Protocol -- HTTP/1.0).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground presented an alternative path to proving the "conversational flow" limitation. Petitioner asserted that the combination of Riddle with RFC 1945, which defines the HTTP/1.0 protocol, teaches the concept. RFC 1945 discloses the "Referer" header field, which identifies the source URL that linked to a requested resource. Petitioner highlighted that the Patent Owner’s own expert in separate litigation had testified that using the HTTP Referer field to correlate separate connection flows constitutes a "conversational flow."
    • Motivation to Combine: Riddle provides an explicit motivation to look to HTTP standards, stating that web traffic can be classified by "HTTP header types such as Content-Type (MIME type) or User-Agent." Petitioner argued a POSITA, prompted by this disclosure, would consult the relevant standard (RFC 1945) and recognize that other available header fields, like the Referer field, could be used to classify traffic by linking related flows. This would be a natural extension of Riddle’s goal to improve traffic classification.
    • Expectation of Success: A POSITA would expect success in using the HTTP Referer field for classification, as it was a well-defined mechanism in a standard protocol designed for the purpose of linking web resources.

Ground 3: Obviousness over Riddle, Bruins, and RFCs 1889 & 2326 - Claims 1, 2, 5, 10, 14, and 15 are obvious over Riddle in view of Bruins and further in view of RFC 1889 and RFC 2326.

  • Prior Art Relied Upon: Riddle (Patent 6,412,000), Bruins (Patent 6,308,148), RFC 1889 (RTP: A Transport Protocol for Real-Time Applications), and RFC 2326 (Real Time Streaming Protocol).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground provided a third independent basis for the "conversational flow" limitation, focused on streaming media. Petitioner pointed to the Patent Owner’s admission in a prior IPR that linking separate control channels (RTSP, RTCP) with transport channels (RTP) in a streaming media session creates a "conversational flow." RFC 1889 and RFC 2326 describe these protocols and their use of separate but related connections for control and data.
    • Motivation to Combine: Riddle explicitly discloses classifying streaming traffic (e.g., RealAudio) and the concept of "service aggregates" for applications using multiple connections. A POSITA would be motivated to apply Riddle's classification engine to the known structure of RTP/RTSP sessions described in the RFCs. The RFCs themselves teach mechanisms (e.g., CNAME and SSRC in RFC 1889) to associate the related control and data packets, providing a clear blueprint for how to implement Riddle's "service aggregate" concept for streaming media.
    • Expectation of Success: Combining Riddle's classification methods with the well-defined, interrelated protocols of RTP and RTSP would be a straightforward application of known techniques to achieve the predictable result of classifying a complete media session as a single conversational flow.

4. Key Claim Construction Positions

  • "Conversational Flow[s]": This term was central to all grounds. Petitioner noted that the Patent Owner had previously construed it as "the sequence of packets... as a result of an activity... where some conversational flows involve more than one connection." Petitioner proposed a similar construction clarifying that the "activity creates multiple connection flows." Petitioner argued that the cited prior art invalidates the challenged claims under either construction.
  • "Flow-entry database": Petitioner asserted that this term should be construed as a "database configured to store entries, where each entry describes a previously encountered conversational flow," arguing this construction is supported by the patent and that the prior art meets it.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that the Board should not exercise its discretion to deny institution under §314 and §325 for several reasons.
  • First, although a district court trial was scheduled, it was unlikely to resolve the validity of all challenged claims, as the Patent Owner typically narrows the asserted claims for trial.
  • Second, the prior art asserted in the petition, particularly Bruins, was not available to Petitioners in the parallel district court litigation.
  • Third, this was Petitioner's first IPR challenge to the ’751 patent, and they had no involvement in a prior, unsuccessful IPR filed by a different party (Sandvine).
  • Finally, Petitioner argued the current petition was not cumulative because it relied on new prior art (Riddle, Bruins, RFCs) that cured the deficiencies the Board identified in the prior art (Engel) from the earlier Sandvine IPR.

6. Relief Requested

  • Petitioner requested that the Board institute an inter partes review and cancel claims 1, 2, 5, 10, 14, and 15 of Patent 6,839,751 as unpatentable.