Terminology N Terms in Telephony NAK or NACK - A negative acknowledgement that indicates a block of data was received incorrectly. Reply by the receiving party to the calling station that the previous data message was improperly received or was unintelligible.
Private network is a network of communicationschannels confined to the use of one customer.
The busy hour for an entire network. Node ftmctions need not be restricted to data switching. Geographic subdivision of the territory coveredby a national or integrated numbering plan. NXX - Code that designates a specific central office.