Mainly Mr. Francois and Richar are correct. Mainly there should be a lot of difference between BHCA and BHCC.
We define busy hour as a particular time in which the network experiences the maximum load.The period in which the maximum number of call attempts are made, this is called BHCA, the quantity of calls in one hour of time over the one tgrp is called BHCA of the TGRP.
CA=successful calls +unsuccessful calls
the BHCC is calls completeed in busy hour. It is always less than BHCA. Because it excludes the unsuccessful calls.
ASR in a normal network is 40%
over the trunk it is 35% normally.