WE HAVE A OPTION 81C AND OUR OPERATORS ARE ANSWERING CALLS ON THE INFINITY WHICH IS BY AMTELCO. WE ARE ANSWERING CALLS ON DIGITAL VPC PORTS. WE WANT TO UPGRADE TO Q-SIG. WHAT I CAN'T FIGURE IS HOW TO CONNECT TO THE AMTELCO H100 NETWORK CARD TO THE OPTION 81C. OUR PBX IS ON THE TENTH FLOOR AND THE AMTELCO EQUIPMENT IS ON THE GROUND FLOOR IN THE IT DEP'T. I CAN USE HOUSE PAIRS BUT DO I NEED A CSU ETC IN BETWEEN THE PBX AND AMTELCO EQUIPMENT. THANKS