10-10-2017, 10:22 AM
A call detail register (CDR) is a data record produced by a telephone exchange or other telecommunications equipment that documents the details of a telephone call or other telecommunication transaction (eg, text message) that passes through such installation or device. The log contains several call attributes, such as time, duration, end state, source number, and destination number. It is the automated equivalent of paper tolls that were written and timed by operators for long-distance calls on a hand-held telephone exchange.