Think of the telephone network as the model. 讓我們以電話網為模型來考慮這個問題。
A term applied to a data transmission carried on the public switched telephone network and initiated by dialing the telephone number of the receiving station. 應用于普通開關電話網數據傳輸上的術語,指撥通某接收站的電話號碼就能訪問該系統的性質和動作。