Difference between Circuit Switching and Packet Switching

Circuit Switching

Circuit Switching is a connection-oriented service. It provides a dedicated path from the sender to the receiver. In-circuit switching, a connection setup is required to send and receive data. It has very little chance of data loss and error due to the dedicated circuit, but a lot of bandwidth is wasted because the same path cannot be used by other senders during a congestion. Circuit switching is completely transparent; the sender and receiver can use any bit rate format or framing method.

Advantages of Circuit Switching

• It uses a fixed bandwidth.
• A dedicated communication channel increases the quality of communication.
• Data is transmitted with a fixed data rate.
• No waiting time at switches.
• Suitable for long continuous communication.

Disadvantages of circuit switching

• A dedicated connection makes it impossible to transmit other data even if the channel is free.
• Resources are not utilized fully.
• The time required to establish the physical link between the two stations is too long.
• A dedicated path has to be established for each connection.
• Circuit switching is more expensive.
• Even if there is no transfer of data, the link is still maintained until it is terminated by users.
• Dedicated channels require more bandwidth.

Packet Switching

Packet switching is a connectionless service. It does not require any dedicated path between the sender and receiver. It places an upper limit on block size. In packet switching bandwidth is freely utilized as unrelated sources can be used in any path. It has more chance of data loss and error; the packets may arrive in the wrong order.

Advantages of Packet switching

• It reduces access delay.
• Costs are minimized to great extent. Hence packet switching is a very cost-effective technique.
• Packets are rerouted in case of any problems. This ensures reliable communication.
• It is more efficient for data transmission because no need to establish the path.
• Several users can share the same channel simultaneously. Therefore packet switching makes use of available bandwidth efficiently.

Disadvantages of Packet switching

• In packet switching, the network can not be used in applications requiring very little delay and higher quality of service.
• Protocols used in the packet switching are complex.
• If the network becomes overloaded, packets are delayed or discarded, or dropped. This leads to the retransmission of lost packets by the sender.
• It is not secured if security protocols are not used during packet transmission.

Difference between circuit switching and packet switching

The following table highlights the major differences between circuit switching and packet switching −