What is a DID (Direct Inward Dialing) Number?
In historical terms, a DID is a feature offered by telephone companies in order to serve the needs of their customers via PBX (Private Branch Exchange) systems. In practical terms, a DID number (also called a DDI in Europe and sometimes referred to as a virtual number) is a local telephone number in a selected country or city. These numbers are then forwarded by DID World Wide to PSTN (Plain Old Telephone System – a regular telephone), Voice over IP (VoIP), SIP, H.323, IAX, Skype, MSN or Google Talk anywhere in the world. Typically a DID is used to provide local telephone numbers for customers on a worldwide basis, or to provide access from regular telephones to non-PSTN destinations such as VoIP.
