DID stands for – Direct Inward Dialing

DID is a feature offered by telephone companies for use with their customers’ PABX system , whereby the telephone company  allocates range of telephone numbers associated with one or more phone lines. DID allows a company to assign a personal number to each employee, without assigning a separate physical phone line to connect it to the PABX.  This way, telephony traffic can be split up and managed more easily.

DID requires that you purchase an ISDN or Digital line and ask the telephone company to assign a range of numbers. You will then need DID capable equipment at your premises which consists of BRI, E1 or T1 cards or Gateways.

International DID:

Using DID features telephone companies can assign a phone number from different part of world to your local phone number. For example if you live in Toronto you can have different phone number from another Country/City like U.S. ,  IRAN, China, … on your same Home / Mobile ( Cellphone ) Number  you already have. So anyone in those country/city can just call a local number without pay for long distance charges and you will  receive a call on your phone.