The circuit switching and message switching are the distinct techniques employed to connect multiple devices with each other dedicatedly. The significant difference between the circuit switching and message switching is that the circuit switching constructs a dedicated physical connection between the two devices involved in the communication. On the other side, the message switching technique uses a store and forward mechanism for enabling the interaction between the sender and the recipient.
When we want to connect multiple devices with each other, it is quite difficult to establish a one-to-one communication. One of the solutions is to install a point-to-point connection between each pair of devices, but practically it is not possible. So, switching of a network is used where the series of nodes are interlinked with the help of switches and networking devices.
Content: Circuit switching Vs Message switching
|Basis for comparison||Circuit switching||Message switching|
|Basic||A physical path is set between the two systems to place a telephone call.||The transfer of data is done by storing and forwarding it from and to the switching device.|
|Packet storage||Not stored directly sent.||The data is first stored then forwarded.|
|Transmission media||Analog and digital over various media||Digital over various media|
|Routing||Manual type||Route is selected during call setup|
|Dedicated physical path||Not required||Necessary for the transmission|
|Cost||Greater than the message switching.||Reduced by using store and forward mechanism.|
Definition of Circuit Switching
Circuit switching is a switching technique in which a direct targetted communication link is established between two nodes. The communication path is constructed by connecting a series of links between the network nodes. Physically, link contains a virtual logical channel for the connection. The circuit switching technique is mainly implemented in the telephony where after placing the call the switching equipment searches for the physical path from the address of the caller to the receiver’s telephone.
To make the process happen the three functions are executed.
- Circuit establishment: An end-to-end connection is established between the nodes before transmission of the data.
- Data transfer: The data is commonly transferred in full-duplex mode from sender to receiver.
- Circuit disconnect: When the data transfer is completed the connection is terminated and the engaged resources are deallocated.
Definition of Message Switching
Message switching works in a different manner, in which it first stores the messages and then forwards those messages to the dedicated receiver. Unlike circuit switching, it does not need the dedicated path for the communication. It was the major demerit of the circuit switching where the calling and called parties must be connected with each other through a dedicated path. However, circuit switching is very suitable for the telephone systems as it serves the purpose fairly.
Earlier, the telegraph system was used for enabling electrical communication in place of a telephone. The telegraph system was less expensive than the telephone system because text messages transmitted in this environment are not real-time and conversational. This gives the rise to the store and forward postal system which we are using in the message switching.
In the message switching scheme, the message sent by the source is collected by an operator. The operator transmits the message to the intermediate nodes without having any knowledge about whether the path is vacant for the message or not. The message is transmitted from node to node and stored in a node if the forward node link is unavailable. Once the link is available, the message is sent to the next node.
Every message contains the complete source and destination address. The message switching technique also creates delay, as it makes the message to be stored in a node until it gets the link of the forward node. Although this delay is tolerable as the environment is not real time and is beneficial in utilising the transmission media effectively.
Key Differences Between Circuit Switching and Message Switching
- The circuit switching reserves whole path for the end user to establish the connection. As against, the message switching technique does not set up a real-time communication and send the data from a sender address to the destination address using the network nodes.
- Similar to the telephone system the data is directly sent to the recipient, in circuit switching. In contrast, the message switching first stores the data then forwards it to the nearest available node and the process is repeated.
- The transmission media used in circuit switching is analogue while in message switching, it can be analog as well as digital.
- Addressing in circuit switching is basically geographical. On the contrary, message switching uses hierarchical switching.
- Circuit switching employs the manual routing whereas message switching does not define the route previously, and it is done at the time of call setup.
- The dedicated path for the communication is necessarily required in the circuit switching. Conversely, there is no need of a dedicated path for the message switching.
- The cost of circuit switching is higher than the message switching.
The switching is a technique which assists communication between the two users. However, in circuit switching an entire channel is dedicated for the communication. On the other hand, for message switching the sender and receiver need not to be connected through a link but it uses a store and forward technique for the sending the messages node by node to the destination. In the message switching route is dynamically chosen but in circuit switching route is set up prior to the communication begins.
Debayan Bhaumik says