A call detail record (CDR) is a data record produced by a telephone exchange or other telecommunications equipment that documents the details of a telephone call or other telecommunications transactions (e.g., text message) that passes through that facility or device. The record contains various attributes of the call, such as time, duration, completion status, source number, and destination number. It is the automated equivalent of the paper toll tickets that were written and timed by operators for long-distance calls in a manual telephone exchange. CDR contents A call detail record contains data fields that describe a specific instance of a telecommunication transaction, but does not include the content of that transaction. By way of simplistic example, a call detail record describing a particular phone call might include the phone numbers of both the calling and receiving parties, the start time, and duration of that call. In actual modern practice, call detail records are much more detailed, and contain attributes such as: the phone number of the subscriber originating the call (calling party, A-party) the phone number receiving the call (called party, B-party) the starting time of the call (date and time) the call duration the billing phone number that is charged for the call the identification of the telephone exchange or equipment writing the record a unique sequence number identifying the record additional digits on the called number used to route or charge the call the disposition or the results of the call, indicating, for example, whether or not the call was connected the route by which the call entered the exchange the route by which the call left the exchange call type (voice, SMS, etc.) voice call type (call setup, call continue, call operation, call end, call idle, call busy, out of service call) any fault condition encountered Each exchange manufacturer decides which information is emitted on the tickets and how it is formatted. Examples: Send the timestamp of the end of call instead of duration Voice-only machines may not send call type Some small PBX does not send the calling party In some corporate private branch exchange (PBX) systems, a call detail record is termed a station messaging detail record (SMDR). Uses Call detail records serve a variety of functions. For telephone service providers, they are critical to the production of revenue, in that they provide the basis for the generation of telephone bills. For law enforcement, call