Call Detail Record
What Is a Call Detail Record (CDR)?
A call detail record (CDR) is a data record a voice platform creates for each call, capturing details such as the calling and called numbers, start time, duration and call type. Service providers use CDRs for usage billing, reporting, troubleshooting and dispute handling. A CDR describes the call; it does not contain the call's audio.
What does a CDR contain?
Fields and formats vary by platform, but a CDR typically includes:
Field | Example | Used for |
|---|---|---|
Calling number | The number that placed the call | Attribution and reporting |
Called number | The number that was dialed | Rating and routing analysis |
Start time and date | When the call was set up | Billing periods and troubleshooting |
Duration | How long the call lasted | Usage billing |
Call type and direction | Inbound, outbound, local, long distance, international | Rating rules |
Disposition | Answered, busy, failed or unanswered | Troubleshooting and quality reporting |
Account identifiers | The customer, domain or reseller the call belongs to | Assigning usage to the right account |
Trunk or route | The trunk or path the call used | Carrier reconciliation |
How do service providers use CDRs?
Usage billing: the billing system rates CDRs according to each customer's billing arrangement
Reporting: call volumes, peak times and usage trends per customer
Troubleshooting: tracing failed or dropped calls back to a route or device
Disputes: showing customers the calls behind a charge
Carrier reconciliation: comparing usage with carrier invoices
What happens to CDRs during a platform migration?
CDRs drive usage billing, so they need their own place in the migration plan. Three questions matter:
Collection across the cutover period. During a phased migration, billing systems may need to process CDRs from both the legacy platform and NetSapiens. Establish how CDRs will be collected, attributed and reconciled to avoid missing usage or duplicate charges.
Format differences. CDR fields, call types and identifiers differ between platforms. Rating rules may need adjusting so that NetSapiens CDRs are classified and priced according to the intended billing arrangement.
Historical records. Decide where historical usage will be retained and how it can be accessed before the legacy platform is retired.
Billing dependencies should be discussed during migration planning. Depending on the environment and agreed scope, billing-related checks or updates may be incorporated into the migration workflow. Our guide to NetSapiens billing and CDR migration covers this in detail.
Frequently asked questions
Does a CDR include a recording of the call?
No. A CDR records information about a call, such as who called whom, when and for how long. Call recordings are stored separately, where a recording service is in use.
What is the difference between a CDR and a call log?
A call log is usually a user-facing list of recent calls on a phone or app. CDRs are the platform's records used for billing, reporting and operations, and they usually contain more fields.
How long should CDRs be kept?
That depends on billing, regulatory and contractual requirements, which vary by provider and jurisdiction. Retention should be decided before a legacy platform is retired.
Related terms
Planning a migration? Bring billing into the plan.
Vox Matic can review the systems around your platform, including billing, during migration planning.
NetSapiens is a trademark of Crexendo, Inc. Metaswitch and BroadWorks are trademarks of their respective owners. Otto™ and Forge™ are trademarks of Vox Matic. Vox Matic is an independent migration services provider. References to third-party products are for identification and interoperability purposes only and do not imply endorsement, except where an authorized partnership is expressly identified.