Telnet two devices at the same time 1 C# program

Question

Hi, currently I have one 100% working program used to telnet my Arduino circuit.
I use this C# class found somewhere around the web: Anyway, without this forum, I wouldn't be able to finish my program.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net.Sockets;
namespace USSR
enum Verbs
WILL = 251,
WONT = 252,
DO = 253,
DONT = 254,
IAC = 255
enum Options
SGA = 3
class TelnetConnection
TcpClient tcpSocket;
int TimeOutMs = 100;
public TelnetConnection(string Hostname, int Port)
tcpSocket = new TcpClient(Hostname, Port);
public string Login(string Username, string Password, int LoginTimeOutMs)
int oldTimeOutMs = TimeOutMs;
TimeOutMs = LoginTimeOutMs;
string s = Read();
if (!s.TrimEnd().EndsWith(":"))
throw new Exception("Failed to connect : no login prompt");
WriteLine(Username);
s += Read();
if (!s.TrimEnd().EndsWith(":"))
throw new Exception("Failed to connect : no password prompt");
WriteLine(Password);
s += Read();
TimeOutMs = oldTimeOutMs;
return s;
public void WriteLine(string cmd)
Write(cmd + "\n");
public void Write(string cmd)
if (!tcpSocket.Connected) return;
byte[] buf = System.Text.ASCIIEncoding.ASCII.GetBytes(cmd.Replace("\0xFF", "\0xFF\0xFF"));
tcpSocket.GetStream().Write(buf, 0, buf.Length);
public string Read()
if (!tcpSocket.Connected) return null;
StringBuilder sb = new StringBuilder();
do
ParseTelnet(sb);
System.Threading.Thread.Sleep(TimeOutMs);
} while (tcpSocket.Available > 0);
return sb.ToString();
public bool IsConnected
get { return tcpSocket.Connected; }
void ParseTelnet(StringBuilder sb)
while (tcpSocket.Available > 0)
int input = tcpSocket.GetStream().ReadByte();
switch (input)
case -1:
break;
case (int)Verbs.IAC:
// interpret as command
int inputverb = tcpSocket.GetStream().ReadByte();
if (inputverb == -1) break;
switch (inputverb)
case (int)Verbs.IAC:
//literal IAC = 255 escaped, so append char 255 to string
sb.Append(inputverb);
break;
case (int)Verbs.DO:
case (int)Verbs.DONT:
case (int)Verbs.WILL:
case (int)Verbs.WONT:
// reply to all commands with "WONT", unless it is SGA (suppres go ahead)
int inputoption = tcpSocket.GetStream().ReadByte();
if (inputoption == -1) break;
tcpSocket.GetStream().WriteByte((byte)Verbs.IAC);
if (inputoption == (int)Options.SGA)
tcpSocket.GetStream().WriteByte(inputverb == (int)Verbs.DO ? (byte)Verbs.WILL : (byte)Verbs.DO);
else
tcpSocket.GetStream().WriteByte(inputverb == (int)Verbs.DO ? (byte)Verbs.WONT : (byte)Verbs.DONT);
tcpSocket.GetStream().WriteByte((byte)inputoption);
break;
default:
break;
break;
default:
sb.Append((char)input);
break;
My UI Code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Net.Sockets;
namespace USSR
public partial class mainForm : Form
TelnetConnection tc;
public bool keyPressChecker = false;
public bool connectedChecker = false;
public mainForm()
InitializeComponent();
// webBrowser1.Navigate("http://admin:[email protected]");
this.tc = null;
this.connectedChecker = false;
private void radioButton2_CheckedChanged(object sender, EventArgs e)
try
if (submarineRadioBtn.Checked)
System.Diagnostics.Process.Start("dummySub.exe");
catch (Exception ex)
MessageBox.Show(ex.ToString());
private void centerBtnCamera_Click(object sender, EventArgs e)
private void forwardBtn_Click(object sender, EventArgs e)
if (connectedChecker)
this.tc.WriteLine("W");
private void connectToolStripMenuItem1_Click(object sender, EventArgs e)
try
//create a new telnet connection
tc = new TelnetConnection("192.168.0.102", 23);
if (tc.IsConnected)
connectedChecker = true;
catch (Exception ex)
MessageBox.Show(ex.ToString());
private void controlKeyDownCheckBox_CheckedChanged(object sender, EventArgs e)
if (controlKeyDownCheckBox.Checked == true)
keyPressChecker = true;
else
keyPressChecker = false;
private void controlKeyDownCheckBox_KeyDown(object sender, KeyEventArgs e)
if (keyPressChecker == true)
if (e.KeyCode == Keys.W)
if (connectedChecker)
tc.WriteLine("W");
if (e.KeyCode == Keys.S)
if (connectedChecker)
tc.WriteLine("S");
private void reverseBtn_Click(object sender, EventArgs e)
if (connectedChecker)
tc.WriteLine("S");
private void disconnectToolStripMenuItem_Click(object sender, EventArgs e)
try
tc = null;
connectedChecker = false;
catch (Exception ex)
MessageBox.Show(ex.ToString());
private void controlKeyDownCheckBox_KeyUp(object sender, KeyEventArgs e)
if (keyPressChecker == true)
if (e.KeyCode == Keys.W)
if (connectedChecker)
tc.WriteLine("O"); //decrease to MID PT.
if (e.KeyCode == Keys.S)
if (connectedChecker)
tc.WriteLine("P"); //decrease speed to MID PT.
private void exitToolStripMenuItem_Click(object sender, EventArgs e)
Application.Exit();
Now, what I want to know is this: IS IT POSSIBLE FOR MY C# PROGRAM TO TELNET TWO DEVICES AT THE SAME TIME? 
Thanks
Glenn

Answer 1

try this links :
http://www.codeproject.com/Articles/19071/Quick-tool-A-minimalistic-Telnet-library
http://stackoverflow.com/questions/25116077/send-and-receive-commands-via-telnet-in-c-sharp
http://stackoverflow.com/questions/12283241/ssh-to-server-then-telnet-to-device