TCP Sliding Window Protocol Simulation

Project Overview

This project implements a basic TCP sliding window protocol simulation between a client and server. It was developed to demonstrate core TCP concepts including sequence numbers, acknowledgments, packet loss, and retransmission.

Features

• TCP Sliding Window: Implementation of sliding window flow control mechanism
• Packet Loss Simulation: Client probabilistically drops 1% of packets
• Retransmission Protocol: Dropped packets are retransmitted after a time interval
• Performance Monitoring: Server tracks goodput (received packets / total sent packets)
• Network Resilience: Handles network disruptions and packet loss gracefully

Components

Client (client.py)

• Initiates connection with server
• Sends sequence numbers in a sliding window fashion
• Simulates packet loss (1% drop probability)
• Handles retransmission of dropped packets
• Maintains window size of 500 packets
• Supports up to 10,000,000 packet transmissions

Server (server.py)

• Listens for incoming connections
• Tracks received and missing sequence numbers
• Sends acknowledgments back to client
• Calculates and logs goodput statistics
• Saves sequence data to CSV for later analysis

Usage

1. Start the server on the destination machine:

   python server.py
   

2. Start the client on the source machine:

   python client.py
   

3. By default, the client connects to localhost. To connect to a remote server, modify the host parameter in the PacketClient class initialization.

Configuration Parameters

• window_size: Controls sliding window size (default: 500)
• drop_prob: Probability of packet dropping (default: 0.01 or 1%)
• max_packets: Maximum number of packets to send (default: 10,000,000)
• max_seq: Maximum sequence number (default: 2^16)

Requirements

• Python 3.6+
• Standard Python libraries (socket, struct, threading, logging)