Blocked call is a telephone call that is unable to connect to an intended recipient. The primary reason for such a situation could be that the system connecting the call is busy or the system has been programmed to block calls after it has reached its capacity.
In personal individual terms, blocked calls would refer to blocking a particular phone number to make calls to a recipient. It is performed with the help of the network operator. In some cases, the network operator charges the user a certain fee to provide such services.