Reply To: Traffic in Erlang and BHCA. 23rd January 2003 at 06:19 #35016 JulianGuest Hello Aleximo, BHCA=Traffic (in erl)*Average call holding time (ACHT)/3600 I’ve no idea on Erlang A. For Erlang B, the P(blocking)=(A^C/C!)/sum (n=0..C) (A^n/n!) Regards