首页 > Term: direct distance dialing (DDD)
direct distance dialing (DDD)
A network-provided service feature in which a call originator may, without operator assistance, call any other user outside the local calling area. Note 1: DDD extends beyond the boundaries of national public telephone networks. Note 2: DDD requires more digits in the number dialed than are required for calling within the local area.
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- KeithC3
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