You assign a UCM user to the Standard CAR Admin Users group in UCM. However, the user reports that CAR
cannot be accessed from the Tools menu in Cisco Unified Serviceability.
Which of the following is most likely the cause of the problem? (Select the best answer.)

A.
The Cisco CAR Web Service is not running.

B.
The UCM system is generating CDR files too slowly.

C.
The user does not have the privileges to access CAR.

D.
The CDR Enabled flag is set to FALSE.

E.
The disk space where reports are stored is full.

Explanation:
Most likely, the Cisco CAR Web Service is not running if Cisco Call Detail Records (CDR) Analysis and
Reporting (CAR) cannot be accessed from the Tools menu in Cisco Unified Serviceability. If the CAR Web
Service is not running, CAR will not be available from the Tools menu. To activate the CAR Web Service, click
Tools > Service Activation in Cisco Unified Serviceability, select the call processing server from the Servers
dropdown menu, and then select the check boxes next to the appropriate CDR services.
It is not likely that the CDR Enabled flag is the cause of the problem. The CDR Enabled flag determines
whether a given Cisco Unified Communications Manager (UCM) server will generate CDR reports. If the CDR
Enabled flag is not set to TRUE on a UCM server, CAR reports will not be generated for that server. In a UCM
cluster, the CDR Enabled flag should be set to TRUE on the Publisher server and on all Subscriber servers in
the cluster. In addition, you should verify that the Call Diagnostics are enabled and that the Cisco CAR
Scheduler service is running on the Publisher server.
It is not likely that the rate at which the UCM system is generating CDR files is the cause of the problem. By
default, every UCM server can generate one CDR file and one Call Management Records (CMR) file every
minute for up to one hour. However, the rate at which UCM generates CDR files has nothing to do with whether
the service is available from the Tools menu in Cisco Unified Serviceability. In addition, it is not likely that the
amount of available disk space where reports are stored is the cause of the problem. The oldest CDR files are
deleted on an hourly basis by the CDR Repository Manager’s File Manager process if disk usage reaches a
maximum threshold.The user does have the privileges to access CAR. In this scenario, you have assigned the UCM user to the
Standard CAR Admin Users group. By default, any UCM user can be configured as a CAR administrator by
adding the user to the Standard CAR Admin Users group in UCM. This includes application users and end
users. However, application users cannot access the Individual Bill report even though they might have read
and write access to the CAR database.

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/service/8_0_2/car/CAR/caranrpt.html#wp1050468