Question

What is ISD in telephonic communication ?

• A. Inter Subscriber Dialing
• B. Inter Secure Dialing
• C. International Subscriber Dialing
• D. Intercom Simple Dialing

Answer 1

The correct option is C International Subscriber Dialing

ISD is International Subscriber Dialing . It is placing an international telephone call that is dialed directly by a telephone Subscriber , rather than by a telephone operator .

Calls are initiated by dialing the International call prefix for the originating country ,followed by the country calling code for the destination country , and finally the national telephone number of the destination.