What are Networking Hubs?

A network hub is a basic device in a data communication system. Like a transmission medium such as a twisted pair, it is a hardware device that does not require any software support or requires very little management software.

Network hub

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It is widely used in various occasions.

The main function of the network hub is to reshape and amplify the received signals to expand the transmission distance of the network, and at the same time, concentrate all nodes on the nodes centered on it. It works on the first layer of the OSI (Open Systems Interconnection Reference Model) reference model, the "physical layer". The hub, like the transmission media such as network cards and network cables, belongs to the basic equipment in the local area network and uses CSMA / CD (a detection protocol) access method.

A network hub is a pure hardware network underlying device, and basically does not have the "smart memory" and "learning" capabilities similar to switches. It also does not have the MAC address table that the switch has, so it sends data in a non-targeted manner, but sends it in a broadcast manner. In other words, when it wants to send data to a node, it does not send the data directly to the destination node, but sends the data packet to all nodes connected to the hub.

Network hubs can be divided into passive HUBs, active HUBs, and intelligent HUBs based on the way they process input signals. Passive HUB: It is the most inferior one. It does not perform any processing on the signal, does not extend the transmission distance of the medium, and has a certain effect on the signal. Each computer connected to this hub can receive signals from all other computers on the same hub;

Active HUB: The difference between an active HUB and a passive HUB is that it can amplify or regenerate the signal, so that it extends the effective transmission distance between the two hosts;

Intelligent HUB: In addition to all the functions of the active HUB, the intelligent HUB also has network management and routing functions. In the intelligent HUB network, not every machine can receive the signal, only the computer with the same address port as the signal destination address can receive it. Some intelligent HUBs can choose the best path by themselves, which has a good management of the network.

Classified by structure and function, HUB hubs can be divided into three categories: unmanaged hubs, stacked hubs, and chassis hubs.

From the perspective of local area network, network hubs can be divided into five types: single-relay network segment hub, multi-network segment hub, port switching hub, network interconnection hub, and switching hub.