The Digital Nonsecure Voice Terminal

The digital nonsecure voice terminal (DNVT) is an alldigital four-wire telephone set used for noncryptographic communication over digital channels. It operates at 16 or 32 kbits/s. In this paper we describe the physical and electrical implementation of the telephone. The circuits are described to the block diagram level. The various states or phases of the signaling system, signal recognition codes, protocols, interfaces, etc., are discussed.