[Last Updated 1996]

This page refers to the Mbone multicast tools available in the 1990's.
For current conferencing tools, see TRIUMF Computing Services

Internet conferencing tools at TRIUMF

I have assembled a set of Internet conferencing tools that are available for most of the Unix platforms. There are four main classes of tool:

These tools may be used either point-to-point, or multicast within TRIUMF. We have a connection to the global mbone so we can operate multicast to other sites.

Session Directory

This tool (sd) receives session description packets from the MBone and displays them on an X-terminal. Users may connect to a conference by using sd to open it. sd's default behaviour (to launch nv, vat, wb) may be overridden by the users personal ~/.sd.tcl file, eg. to launch nevot or vic instead. Use the sd.tcl below to get audio on NCD terminals from an alpha.
Note that you may manually launch any of the tools, giving the address, port, and other information on the command line. sd is just a convenient way to do this automatically. (It's also used to get new, random addresses that don't conflict with existing sessions if you are creating your own conference.) One problem with sd is that only one copy can run on one machine - it's designed to run on a workstation, not a server.

sd README file
~/.sd.tcl for NAS, nv


Like Xpaint or Pbrush, it allows two or more users to simultaneously write on an X-window. It uses objects rather than bitmap, so is correspondingly more efficient in terms of bandwidth. It allows import of text files, and a slideshow of pre-prepared PostScript pages. It has a default 32Kb page limit, which may be over-ridden by specifying a P parameter, eg.
wb -P 90000 joe.cool.com
The compression utility lzps should be used to compress PostScript files before transmission. Note, however, that although L-Z compressed PostScript is understood by wb and GhostScript, many printers cannot deal with it.
The whiteboard tool is the LBL conference tool wb. wb will run on any X11 terminal connected to an Alpha, Ultrix, Sun or SGI system, and would be a useful point-to-point adjunct to a regular telephone.

wb README file
lblwb.ps wb documentation


There are several video tools (vic, ivs, nv) which allow one to send and receive slow-scan video pictures. One, nv, allows the user to capture and send an arbitrary area of the X11 screen. Ideally the video tools should be run at a workstation to reduce local net traffic, though they will allow viewing at an X-terminal.
vic appears not to work on monochrome X-terminals.

I have a frame grabber on the Sun SPARCstation sundae (Trailer Gg room 33), which may be used to send video if one can obtain a camera. Note - this is a grabber, not a full-motion video board, so it can't be used to make AVIs or MPEGs.

vic README file
ivs README file
nv README file


The tools (vat, nevot, ivs) are available for audio-capable workstations such as Sun or SGI Indigo. There is a package to run on the Alphas and play sound on audio NCD X-terminals, though it lacks several features of the workstation based tools. Note: You need the custom sd.tcl to run this.

vat README file
nevot README file
nevot for NCD Audio README file
ivs README file


The SGI, Alpha and Linux machines are multicast capable. SunOS is with a kernel patch (applied on sundae), as are I believe the Ultrix machines. A multicast transmission within the TRIUMF subnet can be viewed on several multicast capable machines at once with no increase in net traffic (though retransmission to an X-terminal would result in extra traffic).

Multicast Addressing

Loosely speaking, multicast is a scheme for using ip addresses through to broadcast to several machines simultaneously. Addresses between and are reserved for maintenance protocols and aren't forwarded off your subnet.

Usually one uses the session directory tool sd to pick addresses and port numbers. This tool sends a multicast message with information about the conference. Users at other machines simply click to join. Without using sd, one must give an address & port number to the tools. Typically one chooses a port above 2000.

For more detail about Multicast, see this README.


The mbone, or experimental multicast backbone, is a scheme whereby multicast network segments are linked together by unicast tunnels between machines running a multicast router (mrouted). For more information on the mbone, see this list.

Most of the binaries for Alpha and Ultrix are installed in /triumfcs/local/bin and should work using a standard PATH.
README files and example tcl scripts

Getting LBL Tools

The LBL tools may be found at ftp://ee.lbl.gov/conferencing if you need to upgrade or install them elsewhere. For other tools, you can try some of the links in my mbone page.