To Solve your problem, I have two options, both are working the same. Whichever you like install it. It's easy to configure and use.
You can find the details as bellow.
GNOME PPP is an easy to use graphical dialup connection configuring and dialing tool with system tray icon support.
It uses GNOME/GTK+ for its graphical interface and integrates well in GNOME desktop environment, but it can be used in other environments.
It also uses WvDial dialer as its backend, providing simple configuration via config files. You can also use plain wvdial if you don't have X running.
KPPP is a modem dialer for connecting to a dial-up Internet Service Provider. It displays statistics and accounting information to help users keep track of connection costs.
This package is part of the KDE 4 networking module.
You can find both Apppication on Ubuntu Software Center. both have Graphical Environment. So, you can easily configure and dial-up.