It is a Store and Forward type of switching. In this scheme message or data are divided into packets.This scheme is connection less that mean there is no need to establish connection before transferring message.
Each packet contains not only data but also a header with control information ( such as priority code, source address and destination address ) .The packets are sent over node to node over the network.
At each node or router there is a buffer which store those packets and than router takes decision about path or rout. Here the problem will arise that what will be the size of buffer that store the packets ?
For removing the problem of buffer.We consider a constant size of packet.If the size of packet is constant than we consider the size of buffer according to packet size.
Suppose the packet size is 1KB than the buffer size is also 1KB.
This scheme is not connection oriented so we send different packet through different path.In this scheme utilisation of channel is good.
Advantages of circuit switching over packet switching:
✔ In circuit switching it is guarantee to transfer message or data from some of destination in few seconds.
✔ But in packet switching it is not guarantee to transfer data / message to destination with in few seconds at minimum because here it will wait until the line is not free.
Example:
The good example of store and forward switching is (SMS in mobiles) .In mobiles when we send the SMS and if the line is not free then SMS is store in buffer and when the line is free then it send to destination.
There are two popular approach for packet switching is:
✔ Virtual Circuit Packet Switching
Read About
✔ Virtual Circuit Packet Switching
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