private string ServerHost = string.Empty;
        const int PORT_NUM = 23698;
        const int READ_BUFFER_SIZE = 255;
        private TcpClient client;
        private byte[] readBuffer = new byte[READ_BUFFER_SIZE];


 private void Form1_Load(object sender, EventArgs e)
        {
            try
            {
                if (File.Exists(ipadress))
                {
                    using (StreamReader sr = new StreamReader(ipadress))
                    {
                        ServerHost = sr.ReadLine();  //получаем IP сервера
                    }

                    try
                    {
                        client = new TcpClient(ServerHost, PORT_NUM);
                        client.GetStream().BeginRead(readBuffer, 0, READ_BUFFER_SIZE, new AsyncCallback(DoRead), null);
                    }
                    catch { return; }

                    AttemptLogin();

                    ico = new System.Drawing.Icon("info.ico");
                    notifyIcon1.Icon = ico;
                }
                else
                {
                    ico = new System.Drawing.Icon("warning.ico");
                    notifyIcon1.Icon = ico;
                }
            }
            catch
            {
                ico = new System.Drawing.Icon("warning.ico");
                notifyIcon1.Icon = ico;
            }
        }

private void DoRead(IAsyncResult ar)  // Вот в этой ф-ии и надо рестартануть клиента но что бы я не пробовал не работает
        {
            int BytesRead;
            string strMessage;

            try
            {
                if (client.Connected)
                {
                    BytesRead = client.GetStream().EndRead(ar);
                    if (BytesRead < 1)
                    {
                        return;
                    }
                    strMessage = Encoding.ASCII.GetString(readBuffer, 0, BytesRead);
                    ProcessCommands(strMessage);
                    client.GetStream().BeginRead(readBuffer, 0, READ_BUFFER_SIZE, new AsyncCallback(DoRead), null);
                }
            }
            catch
            {
            }
        }
// далее идут функции получения данных и отправки
 private void SendData(string data)
        {
            StreamWriter writer = new StreamWriter(client.GetStream());
            writer.Write(data);
            writer.Flush();
        }

        void AttemptLogin()
        {
            SendData("CONNECT|" + Environment.UserName);
        }

        private void ProcessCommands(string strMessage)
        {
            string[] dataArray;
            dataArray = strMessage.Split('|');
            switch (dataArray[0])
            {
                case "BROAD":
                    BeginInvoke(new ShowNotify(DisplayText),  new object[] { dataArray[1].ToString() });
                    break;
            }
        }

        private void DisplayText(string id)
        {
           //обработка на клиенте
        }