240 APPENDIX B: PATHBUILDER S330/S310 MODULE AND APPLICATION OVERVIEW
Multi-point Video Conferencing
In multi-point video conferencing an MCU (Multi Conference Unit) device is
connected to one T1-DSX/E1 CBR port of a PathBuilder S600 or PathBuilder
S330/S310 at the central site. The remote PathBuilder S330/S310 switches
communicate with each other via their serial (V.35/RS-366) ports, as they do in
point-to-point video conferencing. In addition, the remote units can communicate
with the MCU at the central site over a vpi/vci associated with a fractional T1/E1
bundle of the CBR port connected to the MCU. When a remote unit dials the
number associated with that vpi/vci, the central unit sees activity on that line and
automatically starts transmitting over the vpi/vci, thus completing the circuit.
Figure 179 illustrates multi-point video conferencing between three remote
PathBuilder S330 switches (#1111, #2222, and #3333) and one central
PathBuilder S600 switch (#4444) connected to an MCU.
Figure 179 Multi-point Video Conferencing
V.35/
RS-449/
RS-530/
X.21
Video/Audio
Codec
RS-366
PBS330
#2222
V.35/
RS-449/
RS-530/
X.21
Video/Audio
Codec
RS-366
PBS330
#3333
V.35/
RS-449/
RS-530/
X.21
Video/Audio
Codec
RS-366
PBS330
#1111
ATM
n x T1/E1
PBS600
#4444
MCU
PathBuilder S600
