Does anyone know how to wire and program the Avaya TN556D ISDN BRI cards for video conferencing? Our (3)existing BRI lines are off of a Nortel PBX and are 1 pair per line, 128K per line for 384K two way video conferencing. The Avaya documentation states that the BRI lines on the TN556D are 4 wire (2 pair) per line and 192K per port. How do I make this work on my existing video conferencing equipment. We have Polycom Viewstations with Triple NT1 modules to connect the ISDN lines.