◈ What is Routing & Switching
◈ IPv4 vs IPv6
Routing is the process of sending data from a source to a destination along a specific path. For example, your device is linked to a nearby router, and the device to which you wish to transfer data is likewise connected to a nearby router, with some intermediate routers in between. That is all there is to it. By which device routing is processed is called router. Routing takes place at the network layer.
Switching, on the other hand, is a method of sending data from a source to a destination by splitting it into many frames and sending it through different ports of a router rather than broadcasting to all ports. As a result, it is common for frames or data packets to arrive at their intended address via several routing paths. It is not necessary for all packets to arrive at receiver thru same path in a datagram network or packet switching network (where routers construct paths for data transit), nor is it necessary for all packets to arrive in the same order.
Switching:
Assume you only have two computers to connect with. Then we can use a cable to link two PCs. Assume, however, that there are more than two computers and that we need to connect them. Mesh connections (where each device is connected to others), ring connections (where each device is connected to a central computer), and bus connections (where each device is connected to a common bus) are some of the solutions available. However, when billions of devices are connected to a network, those strategies are ineffective. We normally look for the most cost-effective option, such as switching in this case.
Circuit Switching:
For better explanation, I'll use a simple example of switching. Each channel in 2G GSM has a bandwidth of 200 KHz. TDM (time division multiplexing) switching allows each channel to handle up to eight devices at once.
We've depicted a TDM swathing in which each device is connected to a single channel by distinct time slots in the diagram above. The multiplexed signal can then be transmitted over the same route that carries data for N users. If B is a receiver device, the sent signal is routed through a nearby router, where the multiplexed signal is demultiplexed so that B receives the right signal. For this purpose, IP addresses are important since the header contains the source and destination addresses, and the signal may be routed through many routers to reach the intended user. Circuit switching is seen in the above example. Packet switching is another major switching method for datagram networks.
Packet Switching:
Circuit switching is not the same as packet switching. The data is separated into packets when packet switching is used. It is also not required that all packets be sent over the same path. When circuit switching is used, the communication path is fixed once it is established. When packet switching is used, each packet is delivered to the receiver over numerous paths.
Let's suppose we need to deliver data from a device connected to Router A and transfer it to a device connected to Router B in the diagram above. For packet switching in a datagram network, the entire data is framed/divided into different blocks (technically, packets/ bytes), and then packets 1,2,3,4&5 are ready to be transferred. Assuming a router (nearby router) has three ports, packets 1 and 2 are sent through port 1, packets 2 and 3 are sent through port 3, while packets 4 and 5 are waiting to be transferred. Once any port becomes free, packet 4 will be sent. Packet 5 follows the same procedure.
Routing:
We've previously gone over some of the most important aspects of routing. Routing is required whenever two devices need to be connected over the internet. And everything takes place at the network layer, using a transmission protocol such as TCP IP. The data layer's role is to frame data. Each data to be sent is given a header and a data portion. We discussed the header portion, which contains the source and destination addresses so that data may be transmitted to the correct location. Routing is not required when communicating between two devices on the same network. It'll be handled by the data layer. Routing is necessary if we need to send data to another network.
In plain languages, when we connect to a router locally, such as in our homes or offices, and there are several users connected to the same router, the router allocates different bandwidth to each user, and users connect to the network via different ports of the same router. When you send a request, the signal travels through a specific port, and when the response from the core network / server arrives, switching is in charge of delivering the correct data packets / information to the correct user, rather than broadcasting to all users connected to the same router's different ports.
When you send mail to a buddy who lives hundreds or thousands of kilometres away, routing is critical in determining the shortest or most appropriate communication or message delivery path between you and your friend. Between you and your buddy, there are many intermediate networks. Routing is not required if you and your friend are both connected to the same network.
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[1] IP v4 vs IPv6
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