NFAS Interface
For Quad T1 lines, you can set the non-facility associated signaling (NFAS) parameters by clicking Boards==>Lines and double-clicking a device using a Quad T1 line. NFAS Details
In the NFAS Interface field, enter an integer between 0 and 19 to uniquely identify the T1 interface in the NFAS group. Up to 20 ISDN Primary Rate Interfaces (PRIs) can be grouped together to share a primary D channel.