Skip to main content
CDR Telecom Billing

What is a CDR File in Telecom? Definition, Explanation and Uses

By BlueRockTEL Team

What is a CDR File?

A CDR (Call Detail Record) file is a file collecting information about phone calls made or received during a specific period. It is provided by the telecom operator or generated by the PABX/PBX server.

The standard format is CSV (comma-separated values), readable with a spreadsheet application like Excel or any text editor. Each row represents a communication event, and each column a specific property of that event.

Types of CDR

Voice Calls

Call CDRs contain the following information:

  • Calling number and called number
  • Call start date and time
  • Duration (in seconds)
  • Customer identifier or extension number
  • Call outcome (answered, busy, no answer)

These records are used primarily to bill customers according to their plan and actual usage.

SMS

SMS CDRs include the recipient and sender numbers, the number of characters in the message, the date and time of sending, and the delivery status.

Mobile Data

Mobile data CDRs add to the standard information the amount of data consumed, expressed in bytes or kilobytes.

What are CDR Files Used For?

CDR files are essential for telecommunications companies. They are used to:

  • Bill customers accurately based on actual consumption
  • Analyse usage patterns and identify consumption trends
  • Detect anomalies — unusual consumption spikes, potential fraud
  • Generate detailed consumption statements for end customers

How BlueRockTEL Processes CDR Files

BlueRockTEL integrates CDR files from all major operators (OVH, Sewan, OpenIP, Networth...) as well as PABX and SBC systems via API. The rating engine values each CDR line according to the pricing rules of the customer record, then automatically generates the corresponding invoices and consumption statements.

For an operator managing hundreds of customers, this entire processing runs in minutes, without manual intervention.

Back to resources