C# Socket - end of receieving detection

Question

Hello, i have some problem with detecting when end of recieve occurs. I want to communicate with Asterisk server, but that isn not the issue here. I have the following code:

 // Connect to the asterisk server.
            Socket clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            IPEndPoint serverEndPoint = new IPEndPoint(IPAddress.Parse("192.168.10.250"), 5038);
            clientSocket.Connect(serverEndPoint);

            // Login to the server; manager.conf needs to be setup with matching credentials.
            clientSocket.Send(Encoding.ASCII.GetBytes("Action: Login\r\nUsername: administrator\r\nSecret: neven1206\r\nActionID: 1\r\n\r\n"));

            int bytesRead = 0;


            do
            {
                byte[] buffer = new byte[1024];
                bytesRead = clientSocket.Receive(buffer);
                Console.WriteLine(bytesRead.ToString());
                //Console.WriteLine(bytesRead + " bytes from asterisk server.");

                string response = Encoding.ASCII.GetString(buffer, 0, bytesRead);
                Console.WriteLine(response);

                
                
            } while (bytesRead != 0);
            
            Console.WriteLine("Connection to server lost.");
            Console.ReadLine(); 
        }

Everything is working except, i'm stuck in do-while. I cannot get to the

Console.WriteLine("Connection to server lost."); 

part of code. I don't know what i'm doing wrong. 
Please help