Protocol software for a packet voice terminal

A Packet Voice Terminal (PVT) has been developed at Lincoln Laboratory to provide voice access to an experimental wideband internetwork packet system. The PVT employs a modular, microprocessor-based structure to provide voice processing, packet voice protocol, and network interface functions. The packet voice protocols are implemented in software in the Protocol Processor (PP) module, which is the primary controlling module of the PVT and which handles interfaces to a voice processor, a network interface processor, and a user instrument. This report describes the software implemented in the Protocol Processor. The implementation of the Network Voice Protocol (NVP-II) and the Stream (ST) protocol are described. Call set-up functions for both point-to-point calls and conferencing, and the methods used for packetization and reconstitution of speech, are described. Problems encountered and solutions which have been implemented are discussed.