EchoServerSocket.cs

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;

namespace EchoServerSocket {
    internal class Program {
        private static void Main(string[] args) {
            while (true) {
                var quit = false;

                var port = 5000;

                if (args.Length > 0) port = int.Parse(args[0]);
                
                var myListner = new TcpListener(new IPAddress(0x00000000), port);
                myListner.Start();

                Console.WriteLine($"{DateTime.UtcNow:o} - Aguardando conexão na porta {port}");

                var mySocket = myListner.AcceptSocket();

                Console.WriteLine($"{DateTime.UtcNow:o} -Cliente conectou");
                var myStream = new NetworkStream(mySocket);
                var reader = new StreamReader(myStream);
                var writer = new StreamWriter(myStream) { AutoFlush = true };

                writer.WriteLine($"{DateTime.UtcNow:o} -Server started on port 5000");

                while (!quit) {
                    var text = reader.ReadLine();
                    if (text != null && text.ToLower() == "quit") {
                        quit = true;
                    }

                    Console.WriteLine($"{DateTime.UtcNow:o} - received from cliente : {text}");
                    writer.WriteLine($"{DateTime.UtcNow:o} - echo server send: " + text);
                }

                myStream.Close();
                mySocket.Close();
                myListner.Stop();

                Console.WriteLine("Cliente desconectou");
            }
        }
    }
}