What is a call restriction?
Call restriction is also known as call barring, it enables you to restrict or bar certain types of call to and from your mobile phone.
You can restrict several types of call:
e.g.: outgoing, international, international when roaming, incoming, incoming when roaming.
How to Use
To select which types of call you wish to restrict/bar please go to: Settings -> Networks -> Call -> Call barring
(The menu structure may differ depending on your model of phone).