Direct dial-in is a telecommunications service that assigns a block of public telephone numbers to a private branch exchange. When an external caller dials one of these numbers, the network passes the dialed digits to the PBX, which routes the call directly to the user's desk phone without passing through a receptionist.
Heard on the job
Provision a block of fifty DDI numbers for the new sales floor so clients can bypass the main switchboard.
Also heard as
- direct dial-in
- direct inward dialing
- DID