Multi-Point Video Conferencing - 3Com SuperStack II PathBuilder S330 Reference Manual

266 A B: P B
PPENDIX ATH UILDER
V.35/
RS-449/
RS-530/
X.21
S330/S310 M A
ODULE AND PPLICATION

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 195 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 195 Multi-point Video Conferencing
Video/Audio
Codec
RS-366
PBS330
#1111
ATM
To set up multi-point video conferencing, you build virtual circuits (defined by
transmit and receive vpi/vci combinations) between the remote units and between
the remote units and the central unit. The remote units can use the same vpi/vci to
communicate with the central unit (one at a time), or you can allocate different
channels and set up separate virtual connections to each remote unit.
Table 40,Table 41, Table 42, and Table 43 list possible routing tables when the
remote units have been allocated different channels on the central unit's T1 line.
O
VERVIEW
Video/Audio
Codec
V.35/
RS-366
RS-449/
RS-530/
X.21
PBS330
#2222
n x T1/E1
PBS600
#4444
Video/Audio
Codec
V.35/
RS-366
RS-449/
RS-530/
X.21
PBS330
#3333
MCU