Broadcasting Presentations with VNC
Sometimes there is a need to broadcast talk slides to a remote audience
member in real time, e.g., to an outside co-author during a conference
talk rehearsal, or to an external committee member for an oral proposal or
a thesis defense. While it is possible to email the slides in advance and
say something like "click" on every slide change, this limits the use of
animations and is overall cumbersome (and may lead to much confusion if
cliques of graphs are mentioned in the talk many times).
Below is one way to broadcast the slides in real time using VNC. It
assumes that the presentation is delivered from a laptop running Windows
XP (see below on how to do this on a Mac). One also needs a Linux box on the UTCS network as "a proxy".
On the UTCS Linux box:
- Set the VNC password to a temporary value that you don't mind sharing
by executing "vncpasswd".
- Run VNC server on the Linux box by executing something like
"vncserver :1 -geometry 1024x768". From here onwards we assume the Linux
box is named "atlas". Try ":2", ":3", etc., if VNC is already running on
":1".
- Open a vncviewer into the server by executing "vncviewer atlas:1". A
window will open with X Window System running via VNC server. In this
window, open a console, and execute "vncviewer -listen". You will see a
message like "vncviewer: Listening on port 5501 (flash port 5401)". Make a
note of the first port number. Close the vncviewer window (one titled
"username's X desktop"), thus leaving the VNC server running with a
listening VNC viewer inside it.
In the conference room:
- Connect the laptop to the LCD projector and the internet (use the
Ethernet cable as it has a lower chance of dropping the connection
than the wireless network).
- Download TightVNC for Windows from http://www.tightvnc.com/download.html,
install it.
- Run a VNC server on the laptop: Start->Programs->TightVNC->Launch
TightVNC Server. The server icon "V" will appear in Windows system tray.
- Right-click on the "V" icon, choose "Add New Client" in the menu,
enter "atlas.cs.utexas.edu::5501" (this is the VNC listening port on the
Linux box from above; note the two colons before the port number).
- External audience can now see (and control) your laptop by running
vncviewer and connecting to "atlas.cs.utexas.edu:1" using your temporary
password.
- Test this from any third-party machine.
You could also try to set up a direct connection to the laptop from
outside (by running TightVNC server on the laptop and adding a client),
but in the past we've had trouble with this approach if the outside
computer is a Windows box with a dynamic IP behind a firewall. Although
the setup described above requires the extra steps with the Linux box, so
far it's been foolproof.
To do this on a Mac, running Mac OS X, follow Misha's instructions above, except that
the 2nd, 3rd, and 4th bullet from the "In the conference room" section
above are replaced by the following bullets:
- Download Vine Server for Mac OS X from http://sourceforge.net/projects/osxvnc/
and install it.
- Find the Vine Server icon in the Applications folder and
double-click it to run the Vine Server. A square window will appear
and the server will start running.
- Make sure the Connection tab is selected. Edit the "Reverse
connection" box. Enter "atlas.cs.utexas.edu" in the "Viewer: Host Name
or IP:" box. Enter "5501" in the "Port" field. The Port field may
appear disabled, but once you click on it, become editable. Do not
change any other fields.
- Click the "Connect" button. If you would like to see what the
server is doing, you may also click the "View Log" button at any time"
UTCS ML Group |
UTCS ML FAQ
Last Update: Oct 25, 2005 by
Misha Bilenko
