Modem Connect Line Interchange Circuits NCL Attribute Name Circuit Description ---------------------------------------------------------------------- carrier detect 109 Data channel received line signal detector clear to send 106 Ready for sending data set ready 107 Data set ready data terminal ready 108/2 Data terminal ready local loopback 141 Local loopback remote loopback 140 Loopback/Maintenance test request to send 105 Request to send ring indicator 125 Calling indicator signalling rate 112 Data signal rate selector(DCE) indicator signalling rate 111 Data signal rate selector (DTE) selector test mode 142 Test indicator