FlavioMiranda,
You would first have to have SMDR enabled in the 2000IPS. If you aren't familiar with this, it's basically a text log that gets sent either through a serial connection or an IP connection when a phone user hangs up from making or taking a call.
It's simply ascii text that includes the extenion number, time, date, duration, trunk route and trunk number, caller id if inbound and other info about that call that just took place.
Most people will then purchase a Call Accounting Software Package to parse this info into reports. Your local NEC dealer should be able to help you with obtaining this software or you can google "Call Accounting Software".
The one we have had good success with is the Trivium Call Analyst. It's affordable and simple to setup.