What Is Switching?
A network is a set of linked devices. Whenever we’ve got multiple devices, we’ve got the issue of how to link them to create one-time communication possible. One alternative is to make a point-to-point link between every pair of devices (a mesh topology) or among a central device and every other device (a star topology). All these approaches, however, are impractical and inefficient when applied to very large networks. The other topologies also can’t be utilized at this stage. Hence better resolution for this state is switching.
Types of Switching
There are basically 3 types of switching method available. Out of 3 methods, circuit switching and packet switching are commonly used but the message switching has been opposed out the general communication procedure but still used in the networking application.
- Circuit switching
- Packet switching
- Message switching
Circuit switching is a method of implementing an end-to-end (communication) channel between nodes before establishing the actual connection. In this method, a dedicated path is established across the sender and the receiver. This is maintained for the entire duration of the communication session.
Circuit switching is generally used in public telecommunication networks to send digital signals (data) over a voice network (analog signals).
Packet switching in the packet switching method, data is divided into packets, each packet includes:
- Intermediate device address information
Individual packets in this method take different routes to reach their destination. There are two types of packet switching methods commonly in used
- Datagram packet switching
- Virtual Circuit Packet Switching
Datagram Packet Switching
In this mode
- Individual Packets are forwarded independently based on their destination address
- Routing decision is made dynamically by the routing protocol
- The routing protocol determines the path which results in sending and receiving of packets in a different order in a network.
- o Ex- Internet is the best example for datagram packet switching.
Virtual Circuit Packet switching
In this mode
- A route is created before packets are forwarded to the destinations.
- The data moves on the same route
- The routing through the network becomes very fast.
- The packets are received in the correct order.
- Ex- A frame-relay type of network is an example for virtual circuit packet switching.
Message switching was a method developed alternatively to circuit switching before packet switching has been released. In message switching, end users communicate by sending and receiving messages that comprised the whole information to be shared. Messages will be the smallest individual unit.
Additionally, the receiver and sender aren’t directly linked. There are numerous intermediate nodes move information and make sure that the message reaches its destination. Message switched data networks are therefore known as hop-by-hop systems.