Creation and Usage of CDR Data

You can enable and disable CDR and CMR processing via service parameters in Cisco CallManager Administration (Service > Service Parameters > select a server > select a service). Select the desired service parameters from the list in Table 7-1, set their values appropriately, and update them. When you modify the CDR-related service parameters, the specified CallManager node changes its processing accordingly within a short time, usually within a few seconds. Table 7-1 lists the service parameters that control and manage CDR data.

Enabling and Disabling CDR Data Generation

The CDR Enabled Flag service parameter (Service > Service Parameters > select a server > Cisco CallManager) determines whether CDR data is generated. CDR data generation is disabled by default when the system is installed because some users do not need CDR data, do not have processing resources to handle it, and because CDRs consume disk space. The default setting prevents the creation of the CDR data (which saves processing time and disk space) unless you explicitly enable its generation. You must set this parameter to True if you want to have CDR data at your disposal.

Note

When you change the setting of the CDR Enabled Flag parameter, it only applies to the CallManager node selected. You should configure it to be the same for all CallManager nodes in the cluster to get consistent and predictable results. If you set the configuration differently on different CallManager nodes, some CDR data is not logged.

Logging or Not Logging Calls with Zero Duration

The CDR Log Calls with Zero Duration Flag service parameter determines whether CDRs for calls that were never connected or were connected for less than a second are generated. The following are three common examples:

• When a user goes off-hook and then on-hook without completing a call.
• When a user completes a blind transfer. (The consultation call does not connect.)
• When a user calls a destination that does not return answer supervision. The most common cases of this are calls to Public Safety Answering Points (PSAP; 911 emergency operator centers in North America). Many of these calls do not return answer supervision and as a result the 911 calls are not logged.

CallManager distinguishes between calls that have a duration of 0 seconds and terminate normally and calls that do not connect because of an error condition. Calls that terminate normally are those that have one of the following termination cause codes:

• 0No error
• 16Normal call clearing
• 31Normal, unspecified

CallManager always generates CDR data for calls that have a duration of 0 seconds and terminate because of an error condition of some sort, regardless of the setting of the CDR Log Calls with Zero Duration Flag service parameter. Calls to busy destinations or bad phone numbers are examples of this type of call. The duration of these calls is 0 because they were never connected, but their CDRs are generated anyway.

CallManager does not generate CDRs for calls that terminate normally and have a duration of 0 seconds, unless the CDR Log Calls with Zero Duration Flag service parameter is set to True. When CDR generation is enabled, CallManager generates a CDR for each call that was connected for 1 second or more.

Tip

The CDR Log Calls with Zero Duration Flag service parameter is valid only when the CDR Enabled Flag service parameter is set to True. If CDR generation is disabled, the setting of the CDR Log Calls with Zero Duration Flag service parameter has no significance.

Enabling and Disabling CMR or Diagnostic Data Generation

You can enable and disable the generation of CMRs through the Service Parameters Configuration page in CallManager Administration (Service > Service Parameters > select a server > Cisco CallManager). You control CMR generation by enabling the Call Diagnostics Enabled service parameter. CMR generation is disabled by default when the system is installed. The system generates CMRs only when the Call Diagnostics Enabled service parameter is set to True. The system generates CDRs based solely on the CDR Enabled Flag setting, so if all you want is CDRs, you do not need to set the Call Diagnostics Enabled parameter to True. If you want CMRs, you must enable call diagnostics specifically.

Cisco recommends that if you enable CMRs, you should also enable CDRs. Several processes, including the purging of CDR data and the processing of CDR data by the CDR Analysis & Reporting tool, are dependent on the existence of CDRs that are associated with CMRs. Problems with CAR and CDR data purge can occur if you have orphan CMRs (CMRs that do not have associated CDRs). If you use a third-party billing application to process CDR data, be aware that some applications purge CDRs but might not purge CMRs. Even if you have both CDRs and CMRs enabled, problems can still occur if the third-party application is deleting only CDRs and not the associated CMRs. One such problem is that over time, the unpurged CMRs can consume all the space on the disk and eventually crash CallManager. Because the purge process keys off CDRs, when the CDRs are deleted, the CMRs remain on the disk. This problem will be fixed in a future CallManager release, but as of release 4.1(2), the possibility for this problem still exists. When you change the setting of Call Diagnostics Enabled, it applies to all CallManager nodes in the cluster.