SpeedTest – Throughput Measurement with Unix Sockets

This project implements a custom SpeedTest application in C, using TCP Unix sockets to measure downlink throughput between a client and a server. The system also includes data visualization and analysis tools in Python for comparing measurements against both active (SpeedTest, iperf) and passive (Wi-Fi sniffer) throughput estimates.

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Table of Contents

• Project Overview
• Compilation
• Running the Server
• Running the Client
• Visualizer & Data Analysis
• Evaluation Scenarios
• File Descriptions
• References

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Project Overview

• Goal: Measure and analyze TCP downlink throughput between a client and server over Wi-Fi, in various scenarios, using your own SpeedTest implementation.
• Architecture: Client-Server written in C using Unix Sockets.
• Features:
  • Aggregated and interval-based throughput measurement
  • 2-second interval reporting for timeseries analysis
  • Long-running server for repeated experiments
  • Python visualizer for plotting and comparing results

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Compilation

Run the following command in the project root to build both server and client:

make

This will produce the server and client executables.

Running the Server

Start the server:

./server

• The server always runs, serving one client at a time.
• It prints throughput (Mbps) every 2 seconds and the aggregate throughput after 30 seconds.

Running the Client

On another terminal or host:

./client <server_ip>

• The client connects to the server and sends data for 30 seconds.
• Throughput (Mbps) is printed every 2 seconds and at the end of the test.

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Visualizer & Data Analysis

The visualizer.py script generates plots and statistics from measurement CSVs.

• Requires: Python 3, numpy, pandas, matplotlib
• Usage example:

python3 visualizer.py

• The script will:
  • Plot throughput time series for each scenario
  • Compare SpeedTest with iperf
  • Analyze Wi-Fi Doctor/sniffer metrics

Evaluation Scenarios

Scenarios are tested for:

• 2.4 GHz & 5 GHz Wi-Fi, both close and far from AP, and with movement.
• Data is collected for each scenario in dedicated CSV files.

File Descriptions

• server.c: Implements the TCP server for SpeedTest. Prints interval and aggregate throughput.
• client.c: Implements the TCP client. Connects to the server, sends data for 30s, prints interval/aggregate throughput.
• Makefile: Automates compilation of client/server.
• visualizer.py: Plots throughput, compares with iperf/sniffer data, saves statistics.
• metrics/: Contains all result CSVs (SpeedTest, iperf, sniffer).
• plots/, statistics/: Output folders for generated visualizations/statistics.

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References

• iperf tool
• Beej’s Guide to Network Programming
• Wireless Throughput Calculations and Limitations
• TutorialsPoint: Unix Sockets Quick Guides