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Welcome to the Silicon Valley Linux Users Group

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SVLUG Live Meeting Video on the MBONE

The SVLUG MBONE video multicasts are temporarily suspended, due to difficulty getting old unmaintained MBONE applications to work with the new video4Linux drivers, and lack of volunteer time to experiment with the right configuration.

Table of Contents

Can You Receive the MBONE?
MBONE Client Software
Sample MBONE Client Screenshots
SVLUG MBONE Transmission Equipment
SVLUG's Future MBONE Plans

The MBONE, or Internet Multicast Backbone, is a multimedia distribution system for the Internet that has been operating since 1992. Though there are many technical explanations for how multicasting works, the general description is that it allows an audio, video, or data stream to be efficiently delivered over the network just to the sites that sign up for that stream. Multicasting avoids the waste of broadcasting or duplication of point-to-point (unicast) data streams.

SVLUG has used the MBONE to distribute live video and audio of its meetings since March 1998, when Linus Torvalds spoke at SVLUG's 10th Anniversary meeting.

SVLUG's MBONE multicasts are made possible by volunteer assistance and lent or volunteer-owned equipment.

Can You Receive the MBONE?

We transmit compressed video at 128Kbps, and audio at 56Kbps. These are separate streams, so you can select audio only. If you do not have enough bandwidth on your Internet link, you cannot watch the SVLUG multicasts online.

Call your network administrators or network provider to inquire whether they can provide a "multicast feed" or "MBONE tunneling". Not all sites are set up for this, so, if you have to convince your network administrators to connect to the MBONE, you may also have to wait while they decide the best method to do so.

If your receiving system is a Linux machine, make sure your kernel has IP multicast enabled. (You can compile a new kernel with that configuration, if you're missing it.) For other systems, follow your vendor's instructions to configure IP multicast in your TCP/IP stack, if it isn't already present.

General and technical information about the MBONE can be found at:

MBONE Client Software

Unix Desktop Software
Tool Name Links
Channel Selector Session Directory (sdr) N/A download
Video LBNL Video Conferencing Tool (vic) Home Page download
(pick one)
Robust Audio Tool (rat) Home Page download
LBNL Audio Conferencing Tool (vat) Home Page download
Integrated Tool Rendez-Vous Home Page N/A

Linux-specific MBONE information or binaries can also be found at:

These tools can also be used to transmit on the MBONE. SVLUG's transmissions are done with sdr, vic, and rat.

Windows Desktop Software
Vendor Product
Cisco Systems IP/TV
ICAST Viewer & Guide

Sample MBONE Client Screenshots

[sdr tuner screenshot]

On Unix systems, the "sdr" session directory application is used like a channel selector. Click on the session you wish to receive from.
(image is actual size)

On Windows clients, a similar display accesses the same channels.
[sdr session info screenshot] After selecting a session, "sdr" will present information about it. Click "Join" to start all the media in use for this session. (On SVLUG multicasts, it's just audio and video. Other channels may have interactive whiteboards or other applications, as well.)
(image is 3/4 size)

SVLUG MBONE Transmission Equipment

At the March 1998 meeting, the MBONE multicast transmission was handled by the MBONE coordinator of the Bay Area Large Installation System Administration (BayLISA) group. The system was a Sun SparcStation running Solaris.

At the April, May, and June 1998 meetings, an on-site MBONE transmission system at Cisco Systems was used to televise the SVLUG meeting. The system was also a Sun SparcStation running Solaris.

SVLUG is constructing a Linux-based video capture system, which will be used at a future meeting.

SVLUG's Future MBONE Plans

We hope that, soon, SVLUG will implement a system where video output from our MBONE system can be put up on the video projectors and audio output to the public address system in the conference center. Then, it would be possible for SVLUG to field questions live from the Internet, from MBONE viewers with their own video capture and transmit capability. (Yes, that means we can see you, if you send video!)

If you're putting together an MBONE viewing system, keep working on it to add video and audio capture capability. It could be used to be seen and heard at upcoming SVLUG meetings!


Before we give you the address, please do not ask us whether you can receive MBONE at your site. We have no way to know your site. For that question, you need to contact your own site's network administrators and install your own copy of the software (if it hasn't already been installed at your site).

For appropriate administrivia, SVLUG's MBONE contact is mbone@svlug.org.

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