Flow-Level Anomaly Detection via ML Rule Translation

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Solution Overview

Problem

Existing network security systems face challenges in scaling packet inspection across large networks due to computational bandwidth constraints and high licensing costs, especially when dealing with complex queries and high-speed interfaces, making it impractical to monitor every network packet effectively.

Innovation Solution

A machine learning-based architecture that translates packet-level rules into flow-level rules, leveraging correlations between packet payload and flow header information to detect unwanted traffic, allowing for real-time or near real-time alerts without the need for exhaustive packet inspection, using flow statistics like NetFlow and ML algorithms to approximate packet signatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If packet inspection is performed at network edge with many monitoring interfaces, then detection coverage is improved, but computational bandwidth constraints are exceeded

Engineering Contradiction:
Improvedetection coverageVSAvoidcomputational bandwidth
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system segments packet-level inspection into flow-level processing by grouping packets into flows based on 5-tuple characteristics. Instead of inspecting every packet individually at multiple interfaces, the system aggregates packet data into flow records and processes them at a lower computational level, reducing the computational burden while maintaining detection coverage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces flow records as an intermediary data structure between packet inspection and detection rules. Flow records aggregate packet information and serve as the unit for rule evaluation, allowing the system to maintain comprehensive monitoring while reducing computational complexity through this intermediate representation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If complex queries are executed for comprehensive packet inspection, then detection accuracy is improved, but computational bandwidth constraints are hit

Engineering Contradiction:
Improvedetection accuracyVSAvoidcomputational bandwidth
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system changes the fundamental parameter of inspection granularity from packet-level to flow-level. By operating on flow records instead of individual packets, the system can execute complex detection queries with reduced computational cost, as flow records aggregate multiple packet characteristics into a single processing unit.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If packet inspection is deployed as router feature, then detection capability is integrated, but licensing costs increase

Engineering Contradiction:
Improvedetection integrationVSAvoidlicensing cost
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The patent creates a simplified copy of packet inspection functionality that operates at flow level rather than requiring full packet inspection capabilities. This flow-based approach can be implemented with lower-cost router features or software solutions, avoiding the need for expensive proprietary packet inspection licenses while maintaining detection functionality.

Inventive Principle:
Principle #26Copying

Data Source

PatentUS9680877B2Systems and methods for rule-based anomaly detection on IP network flow
Publication Date: 2017.06.13 AT&T INTELLECTUAL PROPERTY I L P
  • US9680877B2 patent drawing
  • US9680877B2 patent drawing
  • US9680877B2 patent drawing

AI summary

A system to detect anomalies in internet protocol (IP) flows uses a set of machine-learning (ML) rules that can be applied in real time at the IP flow level. A communication network has a large number of routers equipped with flow monitoring capability. A flow collector collects flow data from the routers throughout the communication network and provides them to a flow classifier. At the same time, a limited number of locations in the network monitor data packets and generate alerts based on packet data properties. The packet alerts and the flow data are provided to a machine learning system that detects correlations between the packet-based alerts and the flow data to thereby generate a series of flow-level alerts. These rules are provided to the flow time classifier. Over time, the new packet alerts and flow data are used to provide updated rules generated by the machine learning system.