Switched Networks

There are two types of networks

• circuit switched
• packet switched

Circuit Switched Networks

• Dedicated connection is established between two stations
• Advantage: guaranteed capacity - once a circuit is established, no other network activity will decrease the capacity of the circuit
• Disadvantage: cost - circuit costs are fixed, independent of traffic
• An example is the Telephone System

Packet Switched Networks

• Network traffic is divided into small packets, usually a few hundred bytes in size
• Advantage: concurrent connections among computers can exist
• Disadvantage: as activity increases, a given pair of communicating computers receives a smaller share of network capacity
• Another advantage: Since multiple machines can share a network, fewer interconnections are required
• Internet is comprised predominantly of packet switched networks