What is the difference between packet switch and circuit switch network?

There are mainly two methodologies for transmitting data over the computer network – 1. Packet Switching  and   2. Circuit Switching.

Packet Switching :

A digital networking communications method that groups all transmitted data – regardless of content, type, or structure – into suitably sized blocks, called packet.

In packet-switching, the packets are sent towards the destination irrespective of each other. Each packet has to find its own route to the destination. There is no predetermined path; the decision as to which node to hop to in the next step is taken only when a node is reached. Each packet finds its way using the information it carries, such as the source and destination IP addresses.

If a packet switch does not have enough resources, it sends a Connect Reject and the Connection Establishment Fails.

Advantage of Packet Switching:

More efficient use of overall network bandwidth due to flexibility in routing the smaller packets over shared links. Packet switching networks are often cheaper to build as less equipment is needed given this ability to share.

Another benefit of packet switching is known as “pipelining”.

Disadvantage of Packet Switching:

Longer delays in receiving messages due to the time required to package and route packets. For many applications, delays are not long enough to be significant, but for high-performance applications like real-time video, additional data compression and QoS technology is often required to achieve the required performance levels.

Potential for network security risks due to the use of shared physical links. Protocols and other related elements on packet switching networks must designed with the appropriate security precautions.

Circuit Switching :

Circuit-switched is a type of network in which a physical path is obtained for and dedicated to a single connection between two end-points in the network for the duration of the connection.

Ordinary voice phone service is circuit-switched. The telephone company reserves a specific physical path to the number you are calling for the duration of your call. During that time, no one else can use the physical lines involved.

Traditional PSTN phone system uses circuit switching while VoIP uses packet switching.

Differences :

Packet Switching

• Variable rate data stream(packed) over a shared connection
• characterized by a fee per unit of information
• Low reliable , subject to congestion

Circuit Switching

• Constant rate data stream(packed) over some dedicated connection
• characterized by a fee per time unit of connection time, even when no data is transferred
• Highly reliable