while checking my CDR reports, things like number of unanswered calls are not the same as I see in Asternic module. in this case which of them are more reliable?
Asternic is only going to report on calls that route into a queue. Asterisk writes events that happen in queues (members added, call comes in, hangups, etc.) to a specific log file (/var/log/asterisk/queue_log) that Asternic ingests. If you want metrics such as unanswered calls, ring times, etc. you have to ensure those calls route into a queue for Asternic to report on.