The Multi-Session Bridge

Paper: 344
Session: D (talk)
Speaker: Lidinsky, William, Fermilab, Batavia
Keywords: video conferencing, wide-area networking, international WAN, world-wide collaboration

The Multi-Session Bridge

G. A. Roediger, W. P. Lidinsky
HEP Network Resource Center
Fermi National Accelerator Laboratory, Batavia, IL 60510, USA


The Multicast BackbONE (MBone) is heavily used to carry Internet video
conferences. The low cost and ease-of-use have made the MBone and its
associated tools (e.g., sdr, vat, vic, wb) very popular. But HEP video
conferences often requires many-to-many sparse network topologies, an
arrangement that cannot easily take advantage of MBone efficiencies.
Moreover, many HEP sites do not support multicast and thus researchers
at those sites are cut off from important meetings. In addition, the
topology of the MBone can cause poor performance or lack of access for
some sites. To solve these problems, HEPNRC has developed the Multi-
Session Bridge (msb) and its companion tool vtc. The msb allows an
arbitrary number of multicast and unicast sessions to be connected in
one or more seamless video conferences. Multiple msbs can also be
connected to form a conference virtual network. The msb also extends
MBone sessions to non-MBone sites through unicast streams. The msb is
being extended to provide secure communications.

The msb system has been and is being used extensively. In 1996 close to
500 conferences were held which consumed over 1000 hours of meeting
time. The use continues unabated. The use of the msb has made packet
video conferencing a reality in the HEP community.