التلفنة المباشرة بشبكة داخلية خاصة - الاتصال الهاتفي المباشر بالأقسام الداخلية لشركة -الاتصال الهاتفي المباشر بشبكة داخلية خاصة

Direct Inward Dialing (DID) is a service of a local phone company (or local exchange carrier) that provides a block of telephone numbers for calling into a company's private branch exchange (PBX) system. Using DID, a company can offer its customers individual phone numbers for each person or workstation within the company without requiring a physical line into the PBX for each possible connection.