Understanding Hubs In Networking| Israh Binoj

A hub is one of the simplest networking devices used to connect multiple devices in a small network. It acts as a central point where data from one device is received and then forwarded to all other connected devices without checking where the data actually needs to go. This simplicity makes hubs easy to use, but also limits their efficiency.

Types of Hubs

1. Active Hub

An active hub works with its own power supply.
It regenerates and amplifies incoming signals before forwarding them, which helps maintain signal strength over long distances.
Because of this, active hubs are used in larger setups or long-distance networks and function similarly to repeaters.

1. Passive Hub

A passive hub has no power supply of its own.
It simply splits the connection and sends the signal as it is, without boosting or strengthening it.
This type of hub is suitable for very small networks where the distance between devices is short.

1. Smart (Intelligent) Hub

A smart hub, also known as an intelligent hub, includes basic management features.
It can monitor network traffic, detect errors, and provide limited network diagnostics.
Although not as advanced as switches, it offers more functionality than basic hubs.

Hub in the OSI Model

Hubs operate at Layer 1: The Physical Layer of the OSI model.
They do not understand MAC addresses or make any forwarding decisions.
Their job is simply to send whatever they receive to all ports.

Number of Ports

Most hubs are available with:

4 ports

8 ports

16 ports

These ports allow you to connect multiple devices within a simple local network.

Why Hubs Are Not Used in Modern Networks

Hubs create one large collision domain.
When multiple devices send data at the same time, collisions occur, causing the network to slow down significantly.
As more devices are added, collisions increase and performance decreases.

Because of this inefficiency, hubs have largely been replaced by switches, which handle traffic much more intelligently.

Half-Duplex Communication

Hubs only support half-duplex mode, meaning:

A device can either send or receive data,

But not both at the same time.

This further slows down communication, especially in busy networks.
In contrast, switches support full-duplex, allowing sending and receiving simultaneously.

How Hubs Transmit Data

1. Bit-by-Bit Transmission

Hubs forward data one bit at a time in the form of electrical signals.

1. No Address Filtering

Hubs do not read MAC addresses.
They cannot direct data to a specific device and instead broadcast everything to all connected devices.

Conclusion

Hubs are simple devices ideal for small or temporary networks, but their limitations are collisions, half-duplex mode, and lack of traffic control make them unsuitable for modern environments. This is why switches have become the standard choice for efficient networking.