The Software IP Report

CAFC Split Favors Patent-Eligibility of Network Monitoring Claims: Packet Intelligence LLC v. NetScout Systems, Inc.

By Charles Bieneman

Categories: Patent Eligibility, Software Patents, The Software IP Report

A split Federal Circuit panel disagreed whether patent claims directed to network monitoring for whether received packets belong to a particular “conversational flow” are directed to an abstract idea. Judge Lourie was joined by Judge Hughes in affirming a district court’s findings of fact and conclusions of law rejecting a defense of patent-eligibility, under 35 U.S.C. § 101 and the Alice/Mayo test, of claims directed to determining whether received packets belong to a particular “conversational flow.” Packet Intelligence LLC v. NetScout Systems, Inc., No. 2019-2041 (July 14, 2020) (precedential) (appeal from the Eastern District of Texas; Judge Gilstrap). Judge Reyna, concurring in the court’s opinion on a host of other issues, dissented with respect to § 101 validity, saying that the patent claims were directed to an abstract idea, and that the case should have been remanded to the District Court for further analysis concerning a possible inventive concept under step two of the patent-eligibility test.

There were three patents in suit: U.S. 6,665,725, U.S. 6,839,751, and U.S. 6,954,789. Claim 19 of the ’789 patent was discussed as representative:

A packet monitor for examining packets passing through a connection point on a computer network, each packets conforming to one or more protocols, the monitor comprising:

(a) a packet acquisition device coupled to the connection point and configured to receive packets passing through the connection point;

(b) an input buffer memory coupled to and configured to accept a packet from the packet acquisition device;

(c) a parser subsystem coupled to the input buffer memory and including a slicer, the parsing subsystem configured to extract selected portions of the accepted packet and to output a parser record containing the selected portions;

(d) a memory for storing a database comprising none or more flow-entries for previously encountered conversational flows, each flow-entry identified by identifying information stored in the flow-entry;

(e) a lookup engine coupled to the output of the parser subsystem and to the flow-entry memory and configured to lookup whether the particular packet whose parser record is output by the parser subsystem has a matching flow-entry, the looking up using at least some of the selected packet portions and determining if the packet is of an existing flow; and

(f) a flow insertion engine coupled to the flow-entry memory and to the lookup engine and configured to create a flow-entry in the flow-entry database, the flow-entry including identifying information for future packets to be identified with the new flow-entry, the lookup engine configured such that if the packet is of an existing flow, the monitor classifies the packet as belonging to the found existing flow; and if the packet is of a new flow, the flow insertion engine stores a new flow-entry for the new flow in the flow-entry database, including identifying information for future packets to be identified with the new flow-entry,

wherein the operation of the parser subsystem depends on one or more of the protocols to which the packet conforms.

District Court Findings and Conclusions

The issue of patent-eligibility having been tried to the bench, the district court made findings of fact concerning step one (abstract idea) of the patent-eligibility test. Considering whether the patents claimed a solution to a technical problem, the district “court found that prior art monitors could not identify disjointed connection flows as belonging to the same conversational flow.” The court further found that the patents made possible metrics for classifying conversational flows that “improved quality and performance of traffic flows.”

The defendant argued that the claims were merely directed to collecting, comparing, and classifying information, and as such” are directed to an abstract idea because they do not explain how to determine whether packets belong to a conversational flow.” Supported by expert testimony that the patents did in fact “describe how one would identify and classify different connections into a conversational flow,” the district court had rejected this argument.

Majority Opinion

Relying on Enfish, LLC v. Microsoft Corp. (Fed. Cir. 2016), and SRI International, Inc. v. Cisco Systems, Inc. (Fed. Cir. 2019), the majority here agreed that representative claim 19 of the ’789 patent “solves a technological problem by identifying and refining a conversational flow such that different connection flows can be associated with each other and ultimately with an underlying application or protocol.” Further, the patent specifications explained deficiencies in no network monitors with respect to identifying disjointed connection flows, and emphasized metrics to solve this problem.

Finally, the majority rejected an argument that Two-Way  Media  Ltd. v. Comcast Cable Communications (Fed. Cir. 2016). The court’s opinion in that case had included dicta that “at step two, the claim, not the specification, must include in inventive concept.”

Dissenting Opinion

Judge Reyna dissented based on his view that “the claims are directed to the abstract idea of identifying data packets as belonging to ‘conversational flows’ rather than discrete ‘connection flows.’” There could have been a saving inventive concept, for consideration of which Judge Reyna would have vacated and remanded to the district court.

A “conversational flow,” Judge Reyna pointed out, was defined by the inventors simply as packets “exchanged in any direction as a result of any activity.” But the claimed technical solution of better classifying network traffic was not supported by any explanation of how packets were sorted. In other words, “the claimed operations describe only a general method of sorting data packets according to any flow, not a specific means of sorting packets by conversational flow.” (Emphasis in original.) Thus, Judge Reyna thought that the claims recited a technical result, and not a technical solution.

On remand for analysis under Alice step two, Judge Ryan a thought that “the salient factual inquiry should be whether the components and operations recited in each claim contain anything inventive beyond the abstract concept of classifying by conversational flow,” for example, whether there was a difference between reciting conversational flows as in the claims, and the prior art term, “connection flow.”