Hello Durga parsad
Welcome to optisystem,i would suggest you to go through forum for your particular question.Topic regarding GPON has discissed many times in this forum.if then you will find any help,then let us know.In general the capacity of Gpon depends upon Data rate and no. Of user .For gepon it is data rate is 2.5 G for downstream and 1.25 G upstream supporting 1:128 users for 20/40 Km.