PTAB

IPR2021-00887

Microsoft Corp v. Proven Networks LLC

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Key Events
Petition
petition Intelligence

1. Case Identification

2. Patent Overview

  • Title: Use of DPI to Extract and Forward Application Characteristics
  • Brief Description: The ’024 patent describes a method and device for processing network traffic. The system uses an in-line network device to perform deep packet inspection (DPI) to identify an application associated with a data flow, classifies packets based on characteristics of that application, and then inserts the classification information into the packets before forwarding them to downstream devices. This allows downstream devices to perform application-specific processing without needing to conduct their own DPI.

3. Grounds for Unpatentability

Ground 1: Anticipation - Claims 1-4, 7-19, and 22-25 are anticipated by Packeteer ’406

  • Prior Art Relied Upon: Packeteer (Patent 7,742,406).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Packeteer ’406 discloses every element of the challenged claims. Packeteer teaches an "application traffic management device" that receives packets, associates them with an active flow, and performs DPI by inspecting information across OSI layers 2-7 to identify an application. The device then classifies packets based on characteristics of the identified application, such as classifying email packets based on MIME type (text vs. image) or Real-Time Streaming Protocol (RTSP) packets based on the specific network protocol used. Packeteer further discloses inserting this classification information as a "traffic class tag" (c_Tag) into the packet header and forwarding the modified packet to downstream devices, which can then use the tag to perform traffic management functions without redundant classification. Petitioner asserted that Packeteer’s disclosure of analyzing multiple "TCP handshake packets" to identify an email application also meets the limitation of analyzing "at least one other packet." The arguments for device claims 16-19 and 22-25 parallel the arguments for the corresponding method claims.

Ground 2: Obviousness - Claims 7, 11, and 22 are obvious over Packeteer ’406 in view of NBAR

  • Prior Art Relied Upon: Packeteer (Patent 7,742,406) and NBAR ("Classifying Network Traffic Using NBAR," a 2006 Cisco Systems publication).
  • Core Argument for this Ground:
    • Prior Art Mapping: To the extent Packeteer ’406 was found not to explicitly disclose the specific classification criteria of dependent claims 7, 11, and 22, Petitioner argued NBAR supplies the teachings. For claim 7, NBAR teaches classifying packets based on user experience and importance by distinguishing different types of Citrix traffic, such as prioritizing user display updates (interactive traffic) over printing (background traffic) based on user preference. For claim 11, NBAR teaches selecting from a group of audio and video applications by classifying Real-Time Transport Protocol (RTP) flows and differentiating traffic based on specific audio and video codecs to provide granular Quality of Service (QoS). Claim 22 is the device claim corresponding to method claim 7.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine NBAR’s specific classification techniques with the broader traffic management system of Packeteer ’406. Both references address the same problem of DPI-based traffic classification in network devices and explicitly disclose identifying similar applications, such as Citrix flows and Real Time (RT) flows. A POSITA would have been motivated to incorporate NBAR's more advanced, application-specific rules for prioritizing traffic (e.g., Citrix, audio/video codecs) into Packeteer’s system to improve network performance and enhance user experience.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because Packeteer ’406 describes a flexible and hierarchical classification engine capable of supporting a rich set of matching rules. Incorporating NBAR’s specific rules for classifying traffic based on user experience or media codecs would have been a straightforward enhancement to this existing framework.

4. Key Claim Construction Positions

  • Petitioner argued that claim construction was not necessary but addressed constructions from a parallel district court proceeding for context.
  • "Order of steps/limitations" (Claims 1, 16): Petitioner contended its invalidity analysis holds even under the court's construction, which required certain steps to occur in a specific sequence (e.g., for claim 1, associating the packet [b] must occur after receiving it [a], and forwarding the packet [f] must occur last). Petitioner mapped the teachings of Packeteer ’406 to this required order.
  • "analyzing at least one other packet" (Claims 1, 16): Petitioner noted the parties in the district court case agreed this term means "analyzing at least one packet other than the packet" being processed. Petitioner argued Packeteer ’406 meets this construction by teaching, for example, the analysis of initial TCP handshake packets to identify an application before processing subsequent data packets in the same flow.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §314(a) based on Fintiv factors would be inappropriate.
  • The parallel district court litigation against Microsoft was in its infancy, with no scheduling conference held, no Markman hearing date set, and no trial date scheduled.
  • Petitioner stipulated that if the inter partes review (IPR) were instituted, it would not pursue in the district court litigation any invalidity ground that was raised or could have been reasonably raised in the petition.
  • Petitioner further argued that the merits of the petition were particularly strong, which weighs in favor of institution.

6. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 1-4, 7-19, and 22-25 of Patent 8165024 as unpatentable under 35 U.S.C. §102 and/or §103.