Validate TCP Application Performance with RFC 6349 Testing

21st, Jul 2026

Modern enterprise, cloud, and service provider networks increasingly rely on TCP to deliver business-critical applications. While RFC 2544 and ITU-T Y.1564 validate Layer 2 and Layer 3 network performance, they do not measure how real TCP applications perform. ExpertTCP™, an application within GL Communications' PacketExpert™ 100G Ethernet Test Platform, validates true end-to-end TCP throughput using the RFC 6349 methodology, helping identify hidden performance bottlenecks before deployment.

Unlike traditional benchmarking methods that primarily evaluate packet forwarding performance, RFC 6349 measures how efficiently TCP applications utilize the network under real operating conditions. Networks that pass conventional benchmarking can still experience reduced application performance due to latency, retransmissions, congestion, buffering effects, or TCP window limitations. ExpertTCP™ identifies these factors and confidently validates network readiness.

ExpertTCP™

One-Click RFC 6349 Workflow

ExpertTCP™ automates the complete RFC 6349 testing workflow, eliminating manual calculations and simplifying TCP throughput validation. Engineers configure the test once, and the application automatically performs each step in the recommended sequence, ensuring accurate, repeatable, and standards-compliant results.

The automated workflow includes:

  • Path MTU Discovery
  • Baseline Round-Trip Time (RTT) Measurement
  • Bandwidth-Delay Product Calculation
  • TCP Receive Window Optimization
  • TCP Throughput Testing

This automated approach validates TCP performance quickly while minimizing configuration effort and improving testing consistency.


Comprehensive TCP Performance Analysis

ExpertTCP™ supports RFC 6349 testing on Gigabit and 10 Gbps Ethernet networks. It supports up to 16 simultaneous TCP connections, enabling realistic application traffic generation for accurate end-to-end TCP performance validation. Engineers can perform upstream (Client → Server), downstream (Server → Client), or simultaneous bidirectional testing with independent results for each direction.

During test execution, engineers can monitor real-time progress while analyzing key TCP performance metrics, including:

  • TCP Throughput
  • TCP Efficiency
  • Path MTU
  • Baseline RTT
  • Bandwidth-Delay Product
  • TCP Receive Window
  • Transfer Time
  • Retransmissions
  • Per-connection throughput, transmitted/received frames, and byte statistics

These comprehensive measurements identify performance degradation caused by latency, packet loss, retransmissions, buffering effects, and TCP window limitations, enabling faster root-cause analysis and performance optimization.


Flexible Deployment and Web-Based Access

Whether validating a network in the laboratory or verifying performance across remote locations, ExpertTCP™ adapts to different deployment scenarios.

  • Single Device Mode enables one PacketExpert™ 100G system to perform both Client and Server functions using two Ethernet ports for local RFC 6349 testing

  • Client-Server Mode uses two PacketExpert™ 100G systems configured as independent Client and Server to validate TCP throughput across geographically separated network segments

Engineers can configure, execute, monitor, and analyze tests through a browser-based, multi-user interface accessible from standard web browsers on PCs, laptops, and tablets, simplifying test management and collaboration.


Why Engineers Choose ExpertTCP™

ExpertTCP™ helps organizations move beyond traditional network benchmarking by providing meaningful TCP performance insights that improve deployment confidence and simplify network validation.

Key Benefits

  • Validate real end-to-end TCP application performance using the RFC 6349 methodology
  • Automate TCP throughput testing through an integrated RFC 6349 workflow
  • Simulate realistic application traffic using multiple TCP connections
  • Quickly identify TCP performance bottlenecks caused by latency, retransmissions, buffering effects, and TCP window limitations
  • Verify Service Level Agreements before deployment with greater confidence
  • Support interoperability testing, deployment validation, and network troubleshooting
  • Support automated and regression testing using Python
  • Generate detailed PDF and CSV reports for performance analysis

Whether validating enterprise, cloud, telecom, or data center networks, ExpertTCP™ provides the visibility engineers need to verify TCP performance, identify hidden bottlenecks, and confidently validate network readiness before deployment.


Ready to Validate Real TCP Performance

Discover how ExpertTCP™ on PacketExpert™ 100G validates real TCP application performance using the RFC 6349 methodology. Measure throughput, latency, retransmissions, TCP efficiency, and other key performance metrics to confidently verify network readiness, optimize deployments, and simplify troubleshooting.

Learn More About ExpertTCP™.


Why GL Communications?

  • 40+ years of expertise in network testing solutions
  • Comprehensive portfolio of packet capture, packet analysis, traffic generation and network monitoring solutions
  • Support for enterprise, telecom, cloud, data center, 5G and defense networks
  • Deep protocol expertise with support for hundreds of telecom and IP protocols
  • Scalable solutions designed for laboratories, field deployments and Network Operations Centers
  • Continuous innovation focused on simplifying network visibility, accelerating troubleshooting and helping organizations maintain reliable high-performance networks

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