3. Switch

A network cable can only have one data packet in it at any instant.

So if two or more computers want to place a data packet on to the network at exactly the same time, then a 'data collision' will take place. 

The network protocol is set up to deal with this. Basically it declares the collided data as unusable and forces the two computers to re-send their data packets at a slightly different time.

This is fine for a lightly loaded network with only a few computers on-line. You will not notice the small delay caused by data collisions.

 But imagine what happens when a hundred PCs are sharing the same network and they are all wanting to send their data packets. This will most likely result in thousands of data collisions per second - each one costing a small amount of time. You will certainly notice the network 'slowing down'.

 

 

A switch has a number of ports and it stores the addresses of all devices that are directly or indirectly connected to it on each port. 

As a data packet comes into the switch,  its destination address is examined and a direct connection is made between the two machines.

Challenge see if you can find out one extra fact on this topic that we haven't already told you

Click on this link: Network Switch