With direct outward dialing, users are able to make outbound calls to anyone outside of their PBX by dialing the standard format for local, national, or international numbers. Under system settings you can even set a default area code to eliminate the frequent dialing of that code.
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Direct inward dialling (DID), also called direct dial-in (DDI) in Europe and Oceania, is a telecommunication service offered by telephone companies to subscribers who operate a private branch exchange (PBX) system. The feature provides service for multiple telephone numbers over one or more analog or digital physical circuits to the PBX, and transmits the dialed telephone number to the PBX so that a PBX extension is directly accessible for an outside caller, possibly by-passing an auto-attendant.