MBONE TRANSMISSION

World Wide Web Consortium
Workshop
"Real Time Multimedia and the Web"
(RTMW '96)

October 24-25, 1996
INRIA-Sophia Antipolis - France



Getting Started

RTMW '96 will be the first W3C workshop to be transmitted on the MBone. It uses the following tools:

Except for the tools especially mentioned below, you can the most recent versions of all these tools from http://nic.merit.edu/~mbone/index/titles.html

Help files for most of the applications are available at http://www.inria.fr/rodeo/personnel/hoschka/mbone-info.html


fphone improves Internet Audio Quality

Good audio quality is the most important factor when trying to follow a conference such as RTMW over the MBone. Audio quality can be quite low with the most commonly used tool for Mbone transmissions (vat). The reason is that on the Internet, audio packets can be lost, and vat does not deal very well with this problem.

To make sure that audio for RTMW can be received at good quality even in the presence of packet loss, we decided to use a new audio tool for this event, fphone. Tests have shown that even with packet loss rates of up to 30%, fphone is still able to deliver intellegible audio quality to listeners. The reason is that fphone adds redundancy to each audio packet, resulting in the capability to do forward error correction. A redundancy scheme based on the technology used in fphone is currently being standardised within the IETF, so that other audio tools can implement this scheme as well.

Note that fphone is still in beta stage, so "expect unexpected behaviour". However, we believe that it is stable enough to be used for RTMW 96.

What you need to do:


mMosaic allows multicasting of Web pages

mMosaic allows multicasting Web pages. We may use it to broadcast speaker slides written in html, as an add-on to the whiteboard tool.

It is very experimental, and rather a "quick hack" than a well-thought out and fully functional tool at this moment.

What you need to do:


Using SDR with New Tools

To make sdr work with new tools like fphone and mMcast, you need to copy an installation file into the directory ~/.sdr/plugins . For this to work, please make sure that you run version 2.2a23 of sdr (if not, get it from http://nic.merit.edu/~mbone/index/titles.html)

This configuration file is referred to as "sdr plugin", but it is very small (a couple of hundred bytes), and the cost of downloading it is thus much lower than for Netscape plugins.

Use the following configuration files


Multicast Addresses Used

We use the following multicast addresses and port numbers (format: address/port number):


Manual Launch

Instead of using sdr, you can also launch any of the tools manually. To do this, ype in the following commands:



Philipp Hoschka