Call Detail Recording (CDR) collects detailed information about all incoming and outgoing calls on specified trunk groups. If you use Intra-switch CDR, you can also collect information about calls between designated extensions on Communication Manager. Communication Manager sends this information to a printer or to some other CDR output device that collects call records and that might also provide reports.
You can have a call accounting system directly connected to your Avaya server running Communication Manager. If you are recording call details from several servers, Communication Manager can send the records to a collection device for storage. A system called a poller can then take these records and send them to the call accounting system. The call accounting system sorts them, and produces reports that you can use to compute call costs, allocate charges, analyze calling patterns, detect unauthorized calls, and keep track of unnecessary calls.