Simple TCP Protocol Implementation (Python Sockets)

🌐 Project Overview

This project involves the development of a reliable messaging protocol at the application layer, simulating the core functionalities of TCP (Transmission Control Protocol) using Python Sockets. It was developed to demonstrate a deep understanding of reliable data transmission over unreliable networks.

🛠 Technical Features

The protocol successfully implements the following networking milestones:

• TCP Three-Way Handshake: Established a robust connection sequence (SYN -> SYN-ACK -> ACK) with precise sequence and acknowledgment number handling.
• Reliable Data Transmission (Stop-and-Wait ARQ): Engineered a reliable data flow mechanism where each data packet requires a server-side acknowledgment before the next is transmitted.
• TCP Four-Way Teardown: Implemented a graceful connection closure (FIN -> ACK -> FIN -> ACK) to ensure all resources are released correctly.
• Automated Logging & Verification: Every transaction is logged in a standardized JSON format, facilitating real-time monitoring of packet headers and timestamps.

🧪 Quality Assurance & CI/CD

This project follows professional software development standards:

• Automated Testing: Verified via Pytest to ensure protocol accuracy and sequence number logic.
• CI/CD Integration: Utilizes GitHub Actions to automatically run test suites on every commit, ensuring a stable and verified codebase.

📁 Project Structure

• client.py / server.py: Core protocol implementation.
• common.py: Shared logging and formatting utilities.
• .github/workflows/: CI/CD pipeline configuration for automated protocol validation.
• test.py: Comprehensive test suite for handshake and teardown verification.

💻 Tech Stack

• Language: Python
• Libraries: Sockets, JSON, Time
• Testing: Pytest, GitHub Actions

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Developed as part of the Networking Technologies & Management Systems module at IMC University of Applied Sciences Krems.