Modem Connect Line Interchange Circuits NCL Attribute Name Circuit Description ---------------------------------------------------------------------- carrier detect CF Received Line Signal Detector clear to send CB Clear to Send data set ready CC DCE Ready data terminal ready CD DTE Ready local loopback LL Local Loopback remote loopback RL Remote Loopback request to send CA Request to Send ring indicator CE Ring Indicator signalling rate CI Data Signal Rate Selector (DCE) indicator signalling rate CH Data Signal Rate Selector (DTE) selector test mode TM Test Mode