The digital transmission bypasses the telephone company's central office equipment that handles analogue signals.
It is like ISDN in that it uses a single-wire pair to transmit full-duplex data at 128 kbit/s and at distances of up to RRD range[definition needed].
Finally, the user continues to use existing CPE (ISDN BRI terminal adapters, bridges, and routers) to make the CO connections.
This is a key feature because the overloading of central office voice switches by data users is a growing problem for telcos.
The limitation of IDSL is that the customer no longer has access to ISDN signaling or voice services.