Data is transmitted from source to destination by packet switching. So what exactly is packet switching.
In simple words when you send message through an email the message is broken into chunks of small size and then they travel to destination and again get recombined there, and message is displayed to that user.
Just take a look at ‘Figure 1’ –
We have to send message from A to B. we have to make wired communication between them. If distance is 2-3 miles it is possible to do it.
But what if I wanted to send message from India to China, is it possible to place wire between every computer? – No way, therefore packet switching is used.
In figure 2 –
I have to send data from source A to destination H. Then my data first goes to B then to C, D, G and then to H. The data packets get sent and received to many mid stations (C, D, and G). The same process of breaking chunks and joining repeated through all these points. The Source and destinations are almost 5000 miles away, still data got transmitted in through other addresses.
Packet switches are named differently as routers, gateways, bridges etc. Some of its advantages are.
1. All the data chunks travel through same or different paths but gathers at same address.
2. The maximum size of packet if kept limited, buffer management becomes simpler.
3. If one chunk is missed in the transfer, for error recovery only one chunk need to be re transmitted.
So this is how packet switching takes place in the internet world. But thing to notice is that data transfer tries to cover shortest path to reach destination as you can see in Fig.2 that data did not transmitted through E and F. So with the help of packet switching data transfer takes place intelligently and efficiently.