1.Automatic switching system established the call between the calling party their is no third person heard them...this is the great advantage.

2. automatic switching system works faster rather than manual switching system.

3. language is also dependent on automatic exchange.

4.there is  2 type of ratary dialling system:

*pulse dialling

*multifrequency dialling

Here every digit equal to the number of values represented the number of pulses except 0...0 indicated the 10 pulses.

5.signalling tones inform the calling subscriber that the call is established.