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CDR Reports Maximum Duration

Level 1
Level 1

Dear Team,

Our customer required CDR reports of four years, but when we are checking on the CDR Dump duration, we can only see an option to choose 2022,2023. Please suggest what is the maximum duration of CDR reports that can be available in the call manager, also is there any possibility to get the 2021 reports. 

Are there any flags that need to enable to last the reports for a long duration say more than two years?


6 Replies 6


Hi, when there are no files anymore, you cannot download it.

There is not fixed date, till when CUCM stores the CDRs. CUCM stores CDRs as long as it has enough space. If the space is full, then CUCM automatically deletes the oldest one. How fast CUCM needs to delete files, depends on the call volume in the cluster. Therefore, nobody can say, if it last 1 year, 2 years, ...

Maybe also someone delete the CDRs because of full disk size before an upgrade, or something...

If the customer wants to have a backup of the CDR files, then you should configure CUCM to send them to a file server for storage.


Thanks for providing the information.

Please clarify if is there any specific memory size allocated for the CDR database.


AFAIK it is not.

CUCM is not a storage system, it will not hold that much data, it's not meant to. The CAR DB size is fixed, non configurable.

CDRs are only kept for 30 days IIRC

The longest time you can configure it to hold information in the CAR DB, is 6 months. IIRC the default is 3 months. So, absolutely no way you will find data that is older than 6 months in the system.

And that is assuming you don't fill it up in less than that due to the volume of calls, and then older records start being deleted as previously mentioned, I think the limit is around 2 million records.

The only way to keep historical data, and that would be from now on, would be for your customer to configure a SFTP server to work as a CDR repository where CUCM would send a copy of the flat CDRs. Processing those into reports or anything else, would be up to your customer, CUCM dumps the raw CDR data. The other option, would be for the customer to buy a billing server that can either access the information from their data repository, or work as the data repository itself.



if this helps, please rate


Thanks for answering my query.

I found some CDR management from the serviceability page on the CUCM. There it is  configured 300 MB of maximum size and some threshold set using the High watermark and low water mark. 

I believe that would be the parameter CUCM considering for deleting the old CDR data.

Pls confirm..

VoIP Engineer
Level 1
Level 1

As you've noticed, once the CDR database max filesize is reached CUCM will begin to purge old files.  You could offload these to an SFTP server, or even manually download them at intervals. 

The easiest option would be to get a CDR tool like VoIP Detective.  It will allow you to keep years of data, and parse it easily.