Digital Switching

A digital switch is a computer which electronically routes digitally

encoded messages through a network.

Advantages

• Faster

• More Reliable

• More Flexible

• Smaller

• Intelligent

Disadvantages

• Control Complexity

System Switching Components

• Switching matrix

• Controller

• Database

• Line circuits

• Truck circuits

• Common equipment

                                                                                                                                 

Space Switch

Time Switch

T-S-T

S-T-S

Transfer Steps

• “Call” set up

• Acknowledgement (or not)

• Release

Types of Control

• Control Channel

• Packet, Frame or Datagram Switched

                      

Transfer rates: 10mbps to 3.4gbps