basic-rate ISDN
Compare the data rate available with basic-rate ISDN and that available with the ADSL system described in the previous problem. By what factor does ADSL exceed basic-rate ISDN in each direction:
(a) if a voice call is being made simultaneously with data?
(b) if no voice call is being made so that the whole available ISDN rate can be used for data?
basic-rate ISDN