the relationship between bearerbox and smsbox

Hi all, it's the first time i write to here, and i don't know much about
english. So please kind to me if something's wrong.

I'm new to kannel and i want to learn more about it.

i'm using kannel version 1.4.3 now.

As i study, i see bearerbox'job such as a server, accept connections from
smsc and move sms to smsbox to process and receive reply from smsbox and
send it to smsc.

Do i know right?

Can i know "did kannel send sms to smsc or not?, did smsc receive it? and
the delay of this sms? "

thanks

hanv