Thinlinc

ThinLinc is a technology for connecting to the G-Bar system from e.g. your own home computer. Just like ICA, VNC and RDesktop. ThinLinc incorporates several (open source) technologies (VNC, SSH, etc) and it is also possible to play sound through your ThinLinc connection, or to print documents from the G-Bar system to your local printer.

Contents 1 Where can I get it? 2 How do I connect? 3 Printing via ThinLinc 4 How do I work with my local files from my computer under ThinLinc? 5 Sound through ThinLinc 5.1 Linux 5.2 Windows 6 Troubleshooting

Where can I get it?

Clients for Windows, Linux and Mac OS X can be downloaded from the G-Bar download page or Cendio's webpage.

How do I connect?

The use of ThinLinc is very simple:

1. Start ThinLinc (On Linux: /opt/thinlinc/bin/tlclient).
2. Type in server address thinlinc.gbar.dtu.dk, user name and password (DTU login).
3. Click OK and Log in.

Printing via ThinLinc

This is not possible. If it is a file that you can open on your computer, you can download it using SCP (works under Windows as well), and print it when you have finished your ThinLinc session.

How do I work with my local files from my computer under ThinLinc?

This is not possible. Instead, you can use WinSCP (or SCP under Unix and MAC) to transfer files back and forth between your computer, and your home folder on the G-Bar.

Sound through ThinLinc

ThinLinc can automatically set up sound transfer to your Linux client. You can redirect sound to your Windows client also, but is at bit more troublesome and requires Cygwin.

ThinLinc uses the eSound package to transfer sound. Notice that it requires some bandwidth. The transfer rate is around 200kb/s (~2Mbit/s).

Linux

eSound has to be installed, but because ThinLinc starts its own instance of esd (eSound), it is best if esd is not running (and your sound card is available) when you log on with ThinLinc. If you have esd running and don't want to disable it, you can add the option "-as 1" to esd when it is started. This causes esd to release your sound card after one second of inactivity, making it available for the esd startet by ThinLinc.

(Depending on your setup, esd might start automatically at either boot time or when you log in to your computer.)

When starting a new ThinLinc session, before you click Log in, do the following:

1. Click Options
2. Select Graphic session => Options => Export local ressources => Sound.
3. Click Ok and log in.

To be able to play sound, the program you start (in the ThinLinc session) must be started on "This Host" and support eSound. eSound can also be named libesd or just esd. An example with the player xmms:

1. Start a Terminal "This Host"
2. Execute the command: xmms soundfile.mp3
3. Press CTRL-p
4. Select eSound as Output plugin
5. Click Ok and play the sound file.

Windows

ThinLinc has not yet developed sound transfer to Windows clients, but with the help of Cygwin and the eSound package distributed with Cygwin, it can be done.

1. Install Cygwin and be sure to install the eSound package.
2. Start a Cygwin terminal window and type in:

   while true; do esd -tcp; done

3. Start a ThinLinc session (and log in).
   Notice: You cannot choose to export sound on Windows.
4. Start a "This Host" Terminal window
5. Execute command hostname to check which server your are working on.
6. Execute command:

   echo $ESPEAKER

   to check which port number that has been assigned to your sesion. (The number after the colon)
7. Start PuTTY and type in the server name from above.
   (Remember to append .gbar.dtu.dk).
8. Go to Category => Connection => SSH => Tunnels.
9. In the field Source port, type in the port number from above.
10. In the field Destination port, type in localhost:16001
11. Click Remote
12. Click Add.
13. Click Open and log in.

It should now be possible to play sound. An example (same as above):

1. Start a Terminal "This Host"
2. Execute the command: xmms soundfile.mp3
3. Press CTRL-p
4. Select eSound as Output plugin
5. Click Ok and play the sound file.

Troubleshooting

• Some users have reported problems with their firewall (e.g. Norton Firewall) blocking port 22, which is used by ThinLinc. Be sure to let ThinLinc pass the firewall!

• If you get the following error message:

ThinLinc login failed.
(The SSH connection succeeded, but the ThinLinc server connection failed.
Perhaps this server doesn't run a Thinlinc server?)

Please check that ThinLinc is set up to use port 22 (SSH), and not port 80 (HTTP).

• If you experience problems with seeeellllfff-repeating keys while typing in a ThinLinc session (typically on slow connections):
  • start a terminal window,
  • type 'xset r off' at the command prompt.

This will switch off the auto-repeat settings of the ThinLinc session - but auto-repeat will still work, if it is enabled on your local computer.

• If you are running Windows XP SP2 and an antivirus software that isn't recognized by Windows Security Center, the ThinLinc client won't start. To work around this, apply this register file before starting the client. The file can also be found on the G-Bar download page.

• If nothing happens when trying to login, the problem might be caused by unended sessions. You may try to click "End existing session" to see if it helps.

• If you cannot start programs, please consider if you have more violated your quota (usually 1GB) signifantly (e.g., 50GB) before writing us. You will have to clean up before you can start programs again as violating the quota prevents programs from writing data to your home folder.

• Black squares and stripes after login with thinlinc. This happens mostly with Windows 7. Try this: When the login screen comes up after starting thinlinc, choose options and then Optimization. Untick "Auto select" and under "Color level" choose "Medium (256 colors)".