Hi,

you can use ESL (http://wiki.freeswitch.org/wiki/Event_Socket_Library) to receive certain events  http://wiki.freeswitch.org/wiki/Event_list

or you can use information stored in XML CDR data to do your analysis: http://wiki.freeswitch.org/wiki/Mod_xml_cdr

Best regards / Mit freundlichen Grüßen,
Daniel Neubert