Terminal Response Times in Data Communications Systems

A response time analysis for a general class of terminals-to-computer subsystem is presented in this paper. The model used is based on the most advanced data communications system in which terminals are connected to Terminal Control Units (TCU) that are in turn connected to local Front-End Processors (FEP). The line control procedures used to interface a TCU and an FEP may be half-duplex Binary Synchronous Communications (BSC), half-duplex Synchronous Data Link Control (SDLC), or full-duplex SDLC. The models presented here can be used to determine bottlenecks in the entire system and to facilitate the initial phase of system design and configuration.