What type of information does a call detail record (CDR) contain?

A call detail record (CDR) provides specific information related to telephone calls made over a telecommunications network. This record typically includes crucial details such as the time a call was made, its duration, the originating and terminating phone numbers, and sometimes even the type of call (like local, long-distance, or international). This data is essential for billing purposes and for analyzing call patterns, which aids both service providers and users in understanding usage.

The other options touch on different aspects of telecommunications but do not accurately define what a CDR contains. For instance, while customer satisfaction is important, it is not captured in a call detail record. General statistics about network usage might be available through other analytical reports or tools but are not included in the specific, detailed format of a CDR. Similarly, technical specifications of the system pertain to the infrastructure or technology used rather than the call records themselves.