A BHT (Busy Hour Traffic) of XXX
Erlang with YYYY BHCA means that
the average call length is
(XXX / YYY) * 3600 seconds.
BHCA = (BHT * 3600) / Call-Length.
Call-Length = (BHT * 3600) / BHCA.
BHT = (BHCA * Call-Length) / 3600.
Call Length is also called
“Hold time”.