In this tutorial, we will discuss What is HUB in networking? and How it works? also discuss the basic features and types of Hub, Advantages, and Disadvantages of a HUB network.
A HUB is a networking device that is used for connecting multiple devices on a local computer network.
It comes under the Physical layer of the OSI Model(layer-1) which broadcasts the data coming from the input source to all other output computer ports connected with it.
There can be no ports in a hub and data is transmitted to all these ports connected through a computer.
As it is not reliable or we can say that it is not an intelligent device because it does not store the information or data coming from the source as Switch does. Hub transmits all the data coming from the source side to all other computers connected with its port. It’s not an intelligent device because if there are 6 to 10 computers connected on a hub and you want to share the information from computer 1 to computer 5 then it will send information bypassing all the 4 computers connected on its path. The information will pass through all the computers then it will reach the destination.
How Hub Works?
Hub is connected through an electric wire and receives the data from the source device connected to its port and sends it to all the other ports. It doesn’t have any feature of storing and forwarding the information or doesn’t manage any kind of table as the switch does. It simply shares the data from one port to another port connected to it. Hence, there a lot of traffic occurs and the performance becomes very low and sometimes stuck or shut down the whole network.
It basically uses the star topology method physically in which all the devices are connected to a central node and if the central node gets any problem whole network is disturbed, but it logically acts as a bus topology.
Basic Features of Hub Network:
Continuous Broadcast: Hub continuously broadcasts the information whatever it receives or sends information to other connected devices.
Works only local network: Hub is used in local networks only, which means you can use it at the home, office, or small area networks because the hub doesn’t work on larger area networks.
Half-duplex communication: Hub uses the half-duplex mode for communication, as one device can transmit the data at a particular piece of time, Other computers have to wait until the previous transfer of data or information is complete.
Not Act as MAC: Hub is not an intelligent device, because it cannot store the MAC addresses of computers as other devices do.
Single Collision Domain: Hub uses the single collision domain, two computers cannot send data at the same time, and if they will send data at the same time the packets will collide and damage the packets and the hub will shut down.
Why Hub is a Physical Layer device?
The reason for using a hub as a physical device is that because the hub is not an intelligent device, it does not store any data in it and doesn’t manage any table for storing the MAC addresses as the Switch device does. Hub is connected through a large cable, and just simply forward the data, to all the devices connected to it. Two computers cannot send data at the same time, and if they send there will be collision and hub shutdowns.
Types of HUB in Networking
- Active Hub
- Passive Hub
- Intelligent Hub
Active Hub is the hub that requires electricity AC(Alternate Current) because it continous generates signals and amplify the signals. It can monitor the connected devices. It uses the priority method for sending data, which data should send first.
Passive hubs are simple message connector to devices, they are a simple device which receives the data and transmit to next device.
Intelligent Hub is the advanced version of active and passive hubs, if the small networking area want’s to expand into a large networking area then intelligent hubs are used. Any problem in the device connected to an intelligent hub can be detected easily. The transmission rate is high, and a speed of 100Mbps
Advantages of Hub Network
- Boost the signals and helps in extending the network.
- Can support different types of networks.
- Best for small network areas.
- Price is much cheaper than other devices.
Disadvantages of Hub Network
- The main disadvantage is there is no security because the message passes to all the devices connected to the hub.
- Works on Half-duplex so, only one device can communicate at a particular time.
- No-Data retransmission, if message stuck or destroys during communication, no facility of transmitting message again.
- No-storage is, therefore cannot store MAC addresses for reliable communication.
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