Note that the term "CDR" is used for many types of records collected in the telco network, not just for "call"(voice). Collected in a mobile network, there's u

Note that the term "CDR" is used for many types of records collected in the telco network, not just for "call"(voice). Collected in a mobile network, there's usually a record for each event of a mobile phone. Authenticating to the network, attaching to the network. Doing a location update, sending/receiving an SMS, switching routing/tracking area, handover between cells and so on.