What is the Difference Between Circuit Switching and Packet Switching?
Circuit switching and packet switching are two alternative switching strategies for connecting several communicating devices to one another. The table given below shows the difference between circuit switching and packet switching based on various parameters such as address, techniques used, delay, etc.
Key Difference Between Circuit Switching and Packet Switching
In circuit switching, each packet will have an entire path address that is given by the source.
In packet switching, each packet will have only a destination address, routers decide the intermediate path.
Circuit switching does not use the store and forward technique.
Packet switching uses a store and forward technique.
In circuit switching, the data transmission is done by source only.
Data is transmitted through source and intermediary routers in packet switching.
In circuit switching, the delay between the data units is uniform.
In packet switching, the delay between the data unit is variable.
In circuit switching, congestion can occur during the connection establishment phase.
In packet switching, the congestion occurs during the data transfer phase.
Circuit switching is not a fault tolerance technique.
Packet switching is a fault tolerance technique in which is packet can be diverted by the other paths.
What is Circuit Switching?
Knowing the difference between circuit switching and packet switching, let us first discuss circuit switching. A circuit-switched network is made up of a series of switches that are linked together via physical links. A circuit-switched network consists of a group of switches linked by physical links, each of which is divided into n channels.
At the physical layer, circuit switching takes place. Therefore, before starting communication, the stations must make a reservation for the resources to be used during the communication. These resources, such as time slots (TDM), switch buffers, switch processing time, and channels(bandwidth in FDM and switch input/output ports), must remain dedicated during the entire duration of data transfer until the teardown phase.
The circuit switching has three-phase that are as follows:
- Setup phase: Before the two parties (or multiple parties in a conference call) communicate, a dedicated circuit (combination of the channels in links) must be established.
- Data-transfer phase: The two parties can transfer data after establishing the dedicated circuit (channels).
- Teardown phase: When one of the parties needs to disconnect, each switch sends a signal to release the resources.
What is Packet Switching?
After knowing the difference between circuit switching and packet switching, let us discuss packet switching. Packet switching is a connectionless network in which messages, known as packets, are separated and organised. From the source to the destination, each packet is routed independently.
The payload carries the real data in these packets. When the packet arrives at the destination, it is the destination's obligation to arrange the packets in the correct order. Packet-switching technologies are used in most modern Wide Area Network (WAN) protocols, such as TCP/IP, X.25, and Frame Relay.
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