Splunk Inc v. Sable IP LLC

1. Case Identification

• Case #: IPR2021-01469
• Patent #: 8,817,790
• Filed: September 1, 2021
• Petitioner(s): Splunk Inc.
• Patent Owner(s): Sable Networks, Inc.
• Challenged Claims: 1-5, 8-10, 13, 15-16, 19-21, and 26-27

2. Patent Overview

• Title: Identifying and Controlling Network Information Flows
• Brief Description: The ’790 patent discloses systems and methods for identifying, classifying, and controlling information packet flows in a network. The classification is based on observing and analyzing header-independent behavioral statistics of the flows, rather than relying solely on header information like port numbers, which can be unreliable.

3. Grounds for Unpatentability

Ground 1: Obviousness over Olesinski - Claims 1, 2, 4, 8, 19, and 20 are obvious over Olesinski.

• Prior Art Relied Upon: Olesinski (Patent 7,782,793).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Olesinski taught all limitations of the independent claims. Olesinski described a system for real-time statistical classification of network traffic to overcome the unreliability of using port specifications in packet headers. It disclosed processing a flow of packets by sampling them, storing header-independent statistics (e.g., number of sampled packets, cumulative amount sampled, timing) in a "flow information table," and updating these statistics on a per-packet basis. The system then categorized the flow by comparing these statistics against pre-defined classification rules (profiles) to determine a traffic type. Based on this classification, the system performed operations such as assigning processing priorities or discarding packets to manage Quality of Service (QoS).
  • Key Aspects: Petitioner contended that the Examiner in the original prosecution allowed the claims for lacking a system that stores, updates, and categorizes flows using header-independent statistics, but argued that Olesinski, which was not considered, explicitly taught such a system.

Ground 2: Obviousness over Olesinski in view of Papp - Claims 1-5, 8-10, 13, 15-16, 19-21, 26, and 27 are obvious over Olesinski in view of Papp.

• Prior Art Relied Upon: Olesinski (Patent 7,782,793) and Papp (Patent 7,843,843).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that to the extent Olesinski did not render all challenged claims obvious, the combination with Papp did. While Olesinski provided the core framework for statistical flow classification, Papp supplied specific implementation details and taught additional, well-known techniques that a person of ordinary skill in the art (POSITA) would have used. For example, Papp explicitly taught using the "five-tuple" of header information to identify flows, a detail Petitioner argued a POSITA would use to implement Olesinski's system. Further, Papp’s teachings on dynamic reclassification of flows, MPLS/DSCP marking, and specific rate policies (e.g., minimum/maximum rates, moving averages) were argued to make obvious the limitations in dependent claims related to changing QoS indicators (Claim 5), re-routing packets (Claim 9), and specific rate indicators (Claims 13 and 15).
  • Motivation to Combine: A POSITA would combine Olesinski and Papp because both addressed classifying packet flows to improve QoS. A POSITA implementing Olesinski's general system would look to a reference like Papp for specific, known techniques to identify flows and apply sophisticated QoS policies. The combination would yield predictable results and allow for beneficial routing techniques (e.g., MPLS, DSCP marking) to achieve the shared goals of higher speed and better QoS discrimination.
  • Expectation of Success: A POSITA would have a reasonable expectation of success because the combination involved incorporating well-known techniques (e.g., Papp’s flow identification) into a known system (Olesinski's) to achieve predictable improvements in network management.

Ground 3: Obviousness over Yung - Claims 1-2, 4-5, 8, 10, 16, 20, and 27 are obvious over Yung.

• Prior Art Relied Upon: Yung (Patent 7,664,048).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Yung, standing alone, disclosed an analogous system that rendered the claims obvious. Yung taught a bandwidth management device that classified data flows using a heuristic comparison of observed behavioral attributes against known application behavior patterns. This system stored header-independent statistics (e.g., packet count, byte count, inter-flow timing, round trip time) in a "control block object" for each flow and updated these statistics as each packet was processed. Yung's traffic classification engine then identified a traffic class by comparing these behavioral attributes to stored profiles. Based on the classification, Yung’s system enforced bandwidth utilization controls, such as priority policies, rate policies, and discard policies, on the individual packets of the flow.
  • Key Aspects: Yung's system was specifically designed to classify traffic even when it is encrypted or obscured, reinforcing its reliance on behavioral, header-independent statistics rather than payload inspection.

• Additional Grounds: Petitioner asserted that claims 13, 15, and 21 are obvious over Yung in view of Papp, arguing a POSITA would combine Papp's teachings on label-switched paths and specific rate policies with Yung's bandwidth management functionality to improve QoS guarantees.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §314(a) based on Fintiv factors would be inappropriate. The core arguments were that the parallel district court litigation was in its infancy, with a Markman hearing still months away and no substantial discovery having occurred. Petitioner asserted that a stay of the litigation was likely if the inter partes review (IPR) was instituted and that it would stipulate not to pursue the same invalidity grounds in the district court. Finally, Petitioner argued the merits of the petition were particularly strong, as the prior art clearly taught the limitations the Examiner found missing during the original prosecution.

5. Relief Requested

• Petitioner requested the institution of an IPR and the cancellation of claims 1-5, 8-10, 13, 15-16, 19-21, and 26-27 of the ’790 patent as unpatentable.