Hubs

What are Hubs?

Hubs have two or more ports into which you can plug your Computers (although a two-port hub may seem fairly pointless, since it lets you connect only two Computers; two-port hubs tend to be extremely small and intended for creating quick Networks while travelling).

As with Network Adapters. Hubs must support the type of Ethernet you Network uses, so if you have installed Fast Ethernet (100 Base-T) or Gigabit Ethernet (1000 Base-T), make sure your Hub supports it. Modern hubs can auto sense the speed of network and configure their ports appropriately- there is no problem with mixing and matching 10 Base-T devices and Fast Ethernet devices on a single 10/100 auto-sensing hub.

Types of Hub

There are three Types of Hubs- Passive, Switching and Intelligent

1. A Passive Hub

A Passive Hub does nothing more than act as a conduit for the Data from a Computer on one spoke of the wheel to a Computer on another spoke. You need to know three important facts about passive hubs, since they account for the differences with other two types.

First, passive hubs share all the bandwidth on the network internally. So let’s say that you have eight Computers plugged into an 8-port, 10 Base-T passive hub. If you are copying files from one Computer to another. And copying these files is using 5 Mbps of bandwidth, the other six Computers must share the remaining 5 Mbps for whatever else they want to do. That’s because when a packet arrives from a Computer on one spoke, the passive hubs copies it to all the other spokes, even though it’s destined only for particular computer.

Second with the passive hub, the only feedback you get is an LED that indicates when Computer is attached to the port and when traffic is flowing to or from the Computer.

Third a passive hub makes an Ethernet network appear to be one segment, which can limit maximum distance and increase collision.

2. A Switching Hub

A switching hub, also called switch reads the destination address on every packet and sends it to the correct physical port. This variation on the passive hub provides a significant benefit: because each port is a separate connection between the connected devices,rather than shared. Each connection receives the full bandwidth available on that type of Network.

For instances, let’s say our eight-computer network from our passive hub example is now using a switching hub. When you start copying files from one Computer to the other, the switching hub makes those two Computers think that those two Computers are connected directly to one another. The switching hub give them a virtual direct connection.

A switching hub provides improved performance over a a passive hub. It makes a network run faster if you regularly have several pairs of Computer communicating with one another. Switching hubs are also useful when connecting passive hubs and switching hubs together in larger network Configuration. For every small network, whether you use a passive or a switching hub probably doesn’t matter much, but luckily, most hubs are switching hubs these days. Thanks to the lowered cost of necessary circuits.

3. An Intelligent Hub

An intelligent hub adds features that let network administrators monitor traffic passing through the hub and configure each port separately. Typically, you use these feature via a Web Browser connected to a Web Sever embedded in the hub. For the most part, a small network does not need an intelligent hub.