
Introduction
This blog will mainly discuss circuit switching in computer networking. Before jumping on the circuit switching, let’s first understand what switching is,
- Switching is the process of creating a network for one-to-one communication with the help of switches. The switches are the series of interlocked nodes in the switched network.
- Switching can happen at several layers of the TCP/IP protocol suite, which are at the physical layer, data-link layer, and network layer.
Now, you must be eager to know what is circuit switching?
Circuit switching is the connection-oriented network switching method that is commonly used these days. Let’s discuss circuit switching in more detail.
(Also see, Switching Models)
Circuit switching
- Circuit switching is one of the methods of switching.
- Circuit switching is the one method that is commonly used today.
- It is the dedicated connection established between the sender and receiver.
- The transmission of messages in circuit switching is done from the dedicated route, which has been established between the source and the destination.
- Each connection uses only one dedicated channel on each link.
- FDM and TDM are used to divide each link into ‘N’ channels.
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There are three phases of circuit switching connection which are as follows:
- Establishment of Circuit: Intermediate switching centers are used to establish a dedicated path from source to destination. The establishment is checked by transmitting communication signal requests and acknowledgments by sender and receiver.
- Data Transfer: Circuits are used to send data and voice from source to destination. The connection will exist till the end parties are communicating with each other.
- Circuit Disconnection: After the transfer of data, we need to disconnect the connection. This is initiated by any one of the users. The intermediate links are removed from the sender to the receiver.

Source: myreadingroom
Efficiency in Circuit Switching
- Circuit switching is not as efficient when compared with the other two methods of switching because resources are allocated during the entire duration of the connection.
- No other connections can use these resources.
Delay in Circuit Switching
- The delay is minimal in circuit switching despite the low efficiency.
- There is no delay in the transfer of data at each switch.
- Total delay = setup delay + data transfer delay + disconnection delay

source:- datacommandnet
Must Read Subnetting in Computer Networks
Advantages of Circuit Switching
- Circuit switching is beneficial in the long continuous transmission of data.
- We receive a steady rate of data communication due to the dedicated path in circuit switching.
- There are no intermediate delays after the establishment of the circuit.
- Fixed bandwidth is used in circuit switching.
- There is no waiting time at switches.
Disadvantages of Circuit Switching
- The requirement for bandwidth is high.
- The establishment of a connection requires a huge amount of time.
- As the resources can’t be reused again, therefore, the system resources are underutilized.
- Circuit switching is more expensive.
- No other data can be transmitted even if the channel is free due to the dedicated end-to-end connection.
Must Read Stop and Wait Protocol.