Additional 5 Seconds in Call CDR

Hi,

I noticed that the duration of a call as written in the generated CDR is 5 secs longer than the actual call (as measured and indicated in the SBC GUI).

Any Idea where those 5 secs come from ?

For example, assuming the following call (as per the GUI and measured):

00:32:55 - INVITE

00:32:55. - 200 OK

00:33:18 - BYE

00:33:18 - 200 OK

Calculated Call duration: 23 sec.

As per the CDR:

Accounting Session Time: 28 sec <----- 5 Seconds more then the actual time

Cisco Setup Time: 00:32:55.070

Cisco Connect Time: 00:32:55.075

Cisco Disconnect Time: 00:33:23.077 <---- 5 Seconds more then in the GUI.

Regards,

Dan