Computer Networks: Socket Programming

Author: Dhruv Trivedi
Course: CS 436 - Networks and Distributed Computer Systems
Instructor: Noura Limam

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Overview

This project provides a hands-on introduction to TCP and UDP socket programming within a client-server paradigm. The primary functionality is string reversal: a client sends a string to the server over a network, and the server returns its reverse.

The communication follows a two-stage process:

1. 🛠️ Negotiation Stage: Through the server's fixed negotiation port (<n_port>), the client and server determine a random port (<r_port>) for subsequent data transfer.
2. ✅ Transaction Stage: Actual data transfer happens where the client connects using the negotiated <r_port>.

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Running the Program

🛠️ Setting up the Server

1. Navigate to the project's source directory on your server machine:

   cd ./source

2. Start the server by entering:

   python server.py <n_port> <req_code>

   Where:
   • 🔹 <n_port>: The TCP negotiation port number.
   • 🔹 <req_code>: The request code against which the client's requests will be verified.

🛠️ Setting up the Client

1. Navigate to the project's source directory on your client machine:

   cd ./source

2. Start the client by entering:

   python client.py <server_address> <n_port> <req_code> <msg>

   Where:
   • 🔹 <server_address>: The server's address (e.g., "ubuntu2004-008.student.cs.uwaterloo.ca" or "ubuntu2004-008").
   • 🔹 <n_port>: The TCP negotiation port for server communication.
   • 🔹 <req_code>: The client's request code for negotiation.
   • 🔹 <msg>: The string that you'd like the server to reverse.

💡 Note: If the request codes on both the client and server match, the client sends the message to the server and receives its reverse.

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Testing Information

The program has been successfully tested on the following machines:

1. 🌐 Machine Details:

   • Hostname: ubuntu2004-008.student.cs.uwaterloo.ca
   • CPU Type: Intel(R) Xeon(R) CPU E5-2697A v4 @ 2.60GHz
   • Make: Dell Inc.

2. 🌐 Machine Details:

   • Hostname: ubuntu2004-010.student.cs.uwaterloo.ca
   • CPU Type: Intel(R) Xeon(R) Gold 6148 CPU @ 2.40GHz
   • Make: Supermicro

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Screenshots

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