Performance of character-echo-oriented applications on X.25 packet networks

Character-echo delay in a contemporary X.25 network operating at loads up to 50% on access links was measured and analyzed. Queuing analyses support the measurement results. A psychophysical test of computer users was used to establish appropriate delay objectives for character echo. It is concluded that character-echo-oriented applications can be supported with a high degree of user satisfaction when the network design includes packet switches, with low processing delays, fully interconnected trunks, and component utilizations below 40-50%