Juniper Networks Inc v. Packet Intelligence LLC

1. Case Identification

• Case #: IPR2020-00486
• Patent #: 6,954,789
• Filed: February 4, 2020
• Petitioner(s): Juniper Networks, Inc. & Palo Alto Networks, Inc.
• Patent Owner(s): Packet Intelligence LLC
• Challenged Claims: 31, 33-34

2. Patent Overview

• Title: Method and Apparatus for Identifying Sessions and Conversations in a Computer Network
• Brief Description: The ’789 patent discloses a network packet monitor that classifies packets into "conversational flows" based on extracted packet portions. The system is described as using components including a parser, analyzer, and flow-entry database to identify and track related data streams that constitute a single logical communication session.

3. Grounds for Unpatentability

Ground 1: Obviousness of Claim 31 over Riddle, Ferdinand, and Baker - Claim 31 is obvious over Riddle in view of Ferdinand and further in view of Baker.

• Prior Art Relied Upon: Riddle (Patent 6,412,000), Ferdinand (WO 92/19054), and Baker (WO 97/23076).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Riddle, the primary reference, teaches a packet monitor that classifies network traffic into flows, including "service aggregates" that link multiple disjointed flows for a common application (e.g., FTP command and data channels). Petitioner asserted these "service aggregates" meet the key "conversational flow" limitation. Ferdinand, a reference describing a network monitor, was cited to supply conventional and obvious features like databases, buffers, and caches for storing flow-entry information. Baker was added to teach the "compiler processor" limitation of dependent claim 31. Baker describes a network monitor configured using high-level, human-readable protocol description files, which are compiled to initialize parsing operations.
  • Motivation to Combine: A POSITA would combine Riddle with Ferdinand to add the well-known benefits of database storage and caching to Riddle's classification system, improving functionality and performance. A POSITA would further add Baker's compilation teachings to make Riddle's monitor more flexible and easily updatable with new protocols, a recognized benefit in the field.
  • Expectation of Success: The combination involved implementing known technologies (Ferdinand's database, Baker's compiler) into a known system (Riddle's classifier) to achieve the predictable results of improved data management and system flexibility.

Ground 2: Obviousness of Claims 33-34 over Riddle, Ferdinand, and Wakeman - Claims 33-34 are obvious over Riddle in view of Ferdinand and further in view of Wakeman.

• Prior Art Relied Upon: Riddle (Patent 6,412,000), Ferdinand (WO 92/19054), and Wakeman (Patent 5,740,175).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground builds on the Riddle and Ferdinand combination to address the limitations of claims 33 and 34, which recite a "cache subsystem" that includes "content addressable memory cells (CAMs)." Wakeman was introduced to teach these specific elements. Wakeman discloses a network switch that uses a CAM cache to accelerate lookups for Ethernet packet addresses. This maps directly to the claimed cache subsystem providing fast access to flow entries.
  • Motivation to Combine: A POSITA would combine Wakeman's CAM cache with the Riddle/Ferdinand system for the well-understood and predictable benefit of reducing lookup times and improving overall system performance. This was a common design choice for network devices handling high volumes of traffic.
  • Expectation of Success: Adding a cache subsystem to a network monitor was a standard engineering practice to improve performance, and a POSITA would have had a high expectation of success in doing so.

• Additional Grounds: Petitioner asserted additional obviousness challenges based on further combinations with Yu (Patent 6,625,150) and RFC1945. Yu was cited for its teachings of a flexible "policy engine" for flow classification. RFC1945, which specifies the HTTP/1.0 protocol, was cited to show that using HTTP header fields (like "Referrer") to link separate connection flows into a single conversational flow was well known. Petitioner noted that the Patent Owner's own expert had previously identified this technique as creating a "conversational flow."

4. Key Claim Construction Positions

• "conversational flow": This term was central to the petition. Petitioner argued the Board should adopt a narrower construction than in prior proceedings, proposing it be construed as "the sequence of packets that are exchanged in any direction as a result of specific software program activity, where such packets form multiple connection flows that are linked based on that activity."
• Importance: This proposed construction was based on the Patent Owner's own prior statements in litigation and IPR proceedings, where it used examples like a single Skype call (a specific application activity) generating multiple, distinct connection flows (audio, video, control) that together form one "conversational flow." Petitioner argued this narrower construction makes the claims more clearly read on prior art like Riddle's "service aggregates."
• "flow-entry database": Petitioner argued this term should be construed as a "database having a separate entry for each encountered conversational flow," based on statements made by the Patentee during prosecution of a related patent to distinguish over prior art.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) or §314(a) would be inappropriate.
• The asserted prior art references and combinations were never considered by the examiner during prosecution. The Board had also never considered the merits of these specific grounds. Prior IPRs filed by a third-party (Sandvine) were denied based on deficiencies in a different primary reference (Engel), which Petitioner argued were not relevant to the current grounds based on Riddle. Another IPR (filed by Nokia) that relied on some of the same art was terminated before an institution decision.

6. Relief Requested

• Petitioner requests institution of IPR and cancellation of claims 31 and 33-34 as unpatentable.