Editing Direct distance dialing (section)

{{Short description|Telecommunication service}}

'''Direct distance dialing''' ('''DDD''') is a [[telecommunications]] service in North America by which a [[call originator|caller]] may call any other [[User (telecommunications)|subscriber]] outside the local calling area without [[operator assistance]], DDD was introduced in the United States in 1951, on a trial basis, with service from Englewood, New Jersey.  Direct long-distance dialing by subscribers requires extra digits, called an [[area code]], to be dialed as prefixes to the directory telephone number of the destination. International Direct Distance Dialing (IDDD) extends the system beyond the geographic boundaries of the [[North American Numbering Plan]] (NANP).