CALLS CONNECTION METHOD BY RING BACK TONE

摘要

The method is for checking the ring back signal coming through the public telecommunication network after dialing-up the counter phone number so that the loop of the public telecommunication network is formed selectively by discriminating whether the counter system is connected to a MODEM or a normal communication network. The system includes a data accuss arrangement (DAA) circuit (50) for amplifying the analog signal transmitting between the MODEM and the public telecommunication.