Content-Based Packet Sampling for Network Analysis

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Solution Overview

Problem

Conventional packet sampling methods either fail to provide sufficient packets for accurate network traffic analysis by randomly sampling every Nth packet or only sample specific flows, leading to missed detection of malicious traffic and incomplete analysis.

Innovation Solution

A method that determines packet sampling based on content, adding fields to sampled packets with information about the flow and sampling type, allowing for flexible sampling decisions based on flow keys, probabilities, and active flows, enabling efficient resource management and comprehensive analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If random sampling every Nth packet is used, then hardware resources are managed efficiently, but sufficient packets of interest cannot be sampled for accurate analysis

Engineering Contradiction:
Improvehardware resource management efficiencyVSAvoidanalysis accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies local quality by differentiating sampling strategies based on packet characteristics. Instead of uniform random sampling, the system identifies packets with specific flow keys (indicating they belong to flows of interest) and applies targeted sampling to those packets while maintaining probabilistic sampling for others. This ensures packets of interest are prioritized for analysis while still managing hardware resources efficiently.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The sampling rate is made dynamic rather than static. The system adjusts the sampling probability based on real-time conditions, including the current sampling rate, packet flow key identification, and detected traffic patterns. This dynamic adjustment allows the system to optimize between resource consumption and analysis accuracy depending on the network state and analytical needs.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If all packets matching a predetermined flow key are sampled, then complete analysis can be performed for a given flow, but information from other flows is unavailable

Engineering Contradiction:
Improveflow analysis completenessVSAvoidoverall analysis coverage
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent changes the sampling parameter from deterministic (all packets with flow key X) to probabilistic (packets with probability P of being sampled). This allows the system to sample a representative subset of packets from multiple flows rather than exhaustively sampling all packets from a single flow, thereby maintaining analysis completeness while expanding coverage to include other flows.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system applies partial sampling to flows of interest rather than complete sampling. By sampling packets probabilistically across all flows rather than deterministically within specific flows, the system achieves sufficient statistical representation to perform meaningful analysis while avoiding the exclusivity that prevents analysis of other flows.

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If the same flow key is associated with many different flows, then resource utilization is optimized, but malicious traffic detection is compromised

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidmalicious traffic detection capability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system incorporates feedback mechanisms that continuously monitor network traffic patterns, flow characteristics, and detection results. When packets with the same flow key are detected, the system uses feedback information about traffic patterns, packet contents, and historical data to dynamically adjust sampling decisions. This feedback loop enables the system to distinguish between legitimate multi-flow scenarios and malicious traffic patterns, maintaining detection reliability while optimizing resource usage.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS7852785B2Sampling and analyzing packets in a network
Publication Date: 2010.12.14 AT&T LABS INC
  • US7852785B2 patent drawing
  • US7852785B2 patent drawing
  • US7852785B2 patent drawing

AI summary

The preferred embodiments of the present invention can include sampling packets transmitted over a network based on the content of the packets. If a packet is sampled, the sampling unit can add one or more fields to the sampled packet that can include a field for a number of bytes contained in the packet, a packet count, a flow count, a sampling type, and the like. The sampled packets can be analyzed to discern desired information from the packets. The additional fields that are added to the sampled packets can be used during the analysis.