【My Study Note】Hubs and Switches
Hubs and Switches
Cables allow you to form point-to-point networking connections. These are networks where only a single device at each end of the link exists. However, these point-to-point networking connections are not super useful in a world with billions of computers.
Luckily, there are network devices that allow many computers to communicate with each other. And 2 of them would be “Hubs” and “Switches”.
Hub
A hub is a physical layer device that allows for connections from many computers at once. All the devices connected to a hub will end up talking to all other devices at the same time. It’s up to each system connected to the hub to determine if the incoming data was meant for them or to ignore it if it isn’t.
This causes a lot of noise on the network and creates what’s called a collision domain.
What’s Collision Domain?
A collision domain is a network segment where only one device can communicate at a time. If multiple systems try sending data at the same time, the electrical pulses sent across the cable can interfere with each other. This causes these systems to have to wait for a quiet period before they try sending their data again. It really slows down network communications and is the primary reason hubs are fairly rare.
Network Switch
A network switch, originally known as a switching hub is very similar to a hub since you can connect many devices to it so they can communicate. The difference is that while a hub is a layer one (Physical Layer Device), a switch is a layer two (Data Link Device).
This means that a switch can actually inspect the contents of the ethernet protocol data being sent around the network, determine which system the data is intended for and then only send that data to that one system.
This reduces or even completely eliminates the size of collision domains on the network. Consequently, this will lead to fewer re-transmissions and higher overall throughput.