Circuit-Switched Network
A dedicated communication channel through the network
The circuit guarantees the full bandwidth
Expensive, but always available, used less often
Was designed for telephone calls (Used very rarely for PC anymore)
The circuit and remain connected for duration of your transmission
When we are using the circuit no one else can use it
The nodes had to be physically connected as with a dedicated electrical circuit
In the early days the circuits have to manually connected by cable operators
Packet-Switched Networks
Data is send in packets and each packet can take different paths to the destination
Cheap, but no capacity guarantee, very widely used today
QoS gives specific traffic priority over other traffic
Modern networks make use of this approach. Routers routes the packet in the network
Data is moved in packets based on the destination address in each packet
The bandwidth and connection of the circuit is shared with other packets
Because of this the internet speed can fluctuate from time to time