IT IS NOT POSSIBLE TO SAY EXACTLY THE FIG OF CALLS BECAUSE ISUP MESSAGES GENERATED BY LANDLINE TO LANDLINE, LANDLINE TO BOBILE, IN CALLS , HOLDING TIME OF EACH CALL IS DIFFERENT. IF IT IS 0.4 ERL
ERL TRAF=CT/60 T=AVG HOLDING TIME AND C =NO OF CALLS. IF U HAVE AVG HOLDING TIME THEN U WILL GET THE CALLS.