@summit.nayak
You modem can work under Ubuntu, atleast it reported to work.
it may no be one click working but it will work.
*neodil.blogspot.com/2007/03/usb-modem-zte-zxdsl-852-install-success.html
For partioning you can use this GPARTED-LiveCD
*gparted-livecd.tuxfamily.org/
not true, some modem are supported
*help.ubuntu.com/7.10/internet/C/modems-adsl-usb.html