Circuit switching and packet switching are the two switching methods that are used to connect the multiple communicating devices with one another. Circuit Switching was particularly designed for voice communication and it was less suitable for data transmission. So, a better solution evolved for data transmission called Packet switching.
The main difference between circuit switching and packet switching is that Circuit Switching is connection oriented whereas, Packet Switching is connectionless. Let us learn some more differences between Circuit Switching and Packet Switching with the help of comparison chart shown below.
Content: Circuit Switching Vs Packet Switching
|Basis for Comparison||Circuit Switching||Packet Switching|
|Purpose||Initially designed for Voice communication.||Initially designed for Data Transmission.|
|Flexibility||Inflexible, because once a path is set all parts of a transmission follows the same path.||Flexible, because a route is created for each packet to travel to the destination.|
|Order||Message is received in the order, sent from the source.||Packets of a message are received out of order and assembled at the destination.|
|Technology/Approach||Circuit switching can be achieved using two technologies, either Space Division Switching or Time-Division Switching.||Packet Switching has two approaches Datagram Approach and Virtual Circuit Approach.|
|Layers||Circuit Switching is implemented at Physical Layer.||Packet Switching is implemented at Network Layer.|
Definition of Circuit Switching
Circuit Switching establishes a physical path between the sender and receiver of the message before a message is delivered. When a connection is established between a sender and a receiver, the entire message travels through the established path from sender to the receiver. Once the message is delivered to the receiver, the source informs the network about the completion of transmission and all the switches released. Then the link and other connecting devices are used to set up another connection.
Circuit switching is always implemented at the Physical Layer. Circuit switching can be explained with an example of a telephone conversation. In a telephone conversation, once a connection is established, between a caller and the receiver, it remains connected, till the whole conversation is finished and both the caller and receiver hang up their phone.
The Circuit switching is not appropriate for data transmission because data is transmitted in spurts (stream) and the line remains idle for most of the times and hence, the bandwidth is wasted. Circuit Switching can be implemented using two technologies either Space Division Switching or Time Division Switching.
Definition of Packet Switching
Packet Switching is connectionless as it doesn’t establish any physical connection before the transmission starts. In packet switching before the message is transmitted, it is divided into some manageable parts called packets. These packets are routed one by one from source to destination.
In packet switching, each packet may follow a different route to reach the destination. Packets arrived at the destination are out of order but, they are assembled in order before the destination forward it to the upper layer.
Packet Switching is always implemented at the Network Layer. Packet switching has two approaches Datagram Approach and Virtual Circuit Approach. In Datagram Approach each packet is independent of other though they belong to the same message and may also choose a different path to reach the destination.
In Virtual Circuit Approach, the relationship between the packets that belong to the same message is preserved as the packet are not independent of each other, and all the packets that belong to a particular message follow the same route to travel to the destination.
Key Differences Between Circuit Switching and Packet Switching
- Circuit Switching is connection oriented that means a path is established between source and destination before the transmission occurs. On the other hand, Packet Switching is Connectionless that means a dynamic route is decided for each packet while transmission.
- Circuit Switching was originally designed for voice communication whereas, Packet Switching was originally designed for data communication.
- Circuit Switching is inflexible as once a path is established for transmission, it doesn’t change while the duration of the session. On the other hand, Packet Switching is flexible as each packet may travel through a different route to reach its destination.
- In packet switching, as each packet travels a different path hence, the packet are received out of order at the receiver side and later arranged in order. On the other hand, in circuit switching the entire message is received as it is as sent from a sender to receiver.
- Space Division Switching or Time-Division Switching can be used to implement Circuit Switching whereas, Packet Switching can be implemented using two approaches Datagram Approach and Virtual Circuit Approach.
- Circuit Switching is always implemented at physical layer whereas, Packet Switching is implemented on the network layer.
For Data transmission, Packet Switching is the more efficient than Circuit Switching whereas, when it comes to voice transmission Circuit switching is more efficient than packet switching.