An isdn stands for integrating services digital network ,it is a
communication media througt which we can transmitte our voice,video
and data, in isdn line two modem are used to for commnication one
at source and other at the destination ,these modems are called
isdn modem
this is Qadar wafa from Kabul
qadarwafa_4all@yahoo.com
qadarwafa@multinet.af
qadar-08@hotmail.com