What is a hub?

A network hub is a small electronic device that acts as a connector for various devices on a network. The primary purpose of the node is to retransmit any data to multiple nodes. The most commonly used hub is an ethernet hub. Other forms of network hubs include USB hubs.

Ethernet hubs

Ethernet hubs can support a range of speeds (also known as bandwidth) in the network. Earlier, ethernet hubs found in homes or small offices could support the transmission of 10 Mbps (Megabits per second) only.

However, with the advancement in technology, ethernet hubs can now support up to 100 Mbps. Nowadays we also have dual-speed hubs (also known as 10/100 hubs) that offer support for both 10Mbps and 100Mbps networks.

Network hubs can connect anywhere between 4 and 24 hosts in a network. Four and five port hubs are commonly used in home networks, whereas small offices would need anywhere between 8 and 16 port hubs.

Note that all the nodes connected via a hub can communicate directly to each other.

Types of hubs

Hubs can also be used to regenerate signals before forwarding them. Based on the function they perform, hubs are classified into three types:

Active hubs

A hub is called to be active if it amplifies the signals before transmitting them. This helps the signal stay strong as it progresses through the network. Active hubs are also called multiport repeaters.

Passive hubs

As the name suggests, these hubs act as a passive connection between multiple devices. The signals received are transmitted without any amplification. These hubs are point contacts for the wires that make up the network.

Intelligent hubs

These are active hubs endowed with additional features. They are stackable. This means that they can be combined to form a bigger hub. This feature allows for the clutter-free and economic growth of the network.

Some intelligent hubs also provide remote management capabilities using SNMP (simple network management protocol) and virtual LAN (VLAN) support. A virtual LAN refers to a logical grouping of devices.

Within a single LAN network, a subset of nodes can be grouped in a virtual LAN such that traffic on one network is not visible to the other.

Working with network hubs

Network hubs work at layer 1 (physical layer) of the OSI (open systems interconnections) models. To use hubs in your network, use an ethernet cable and plug one end in the network hub.

The other end of the cable is used to connect to the network interface card (NIC) of the host computer. Network hubs can also be connected to more network hubs, network switches and routers.

This helps expand the network and is an economical way to accommodate an expanding office.

Over to you

With the advancement in technology, ethernet hubs have shrunk in size and are well designed for mobility. Initially, these hubs came with a built-in fan to help cool the unit. This made the hubs very noisy which is not the case anymore.

Although hubs have improved in size and mobility, they are now being replaced by the more advanced network switch technology. Despite have similar functionality, network switch technology offers performance benefits which are putting hubs out of use now.