subject: Why Do I Need A Switch In My Network? [print this page] The least expensive way to join several computers together is simply to connect them to a hub. A hub is a simple device that simply passes on the information from one computer to all the other computers it is connected to. Each computer decides if that information was meant for it or not.
When networking only a few computers, a hub works well as long as large files of information aren't transferred. Information packets must be transferred one at a time through a hub or collisions occur. When every one on the network is trying to download information at the same time, the transfer rate is significantly slower for all.
A hub is a rather unsophisticated piece of equipment. Any packet of information received through one port, is sent out or repeated to all the other ports. It is considered to have a "layer one" functionality.
A hub uses a broadcast model. When using a hub, if anyone on the network is downloading a large file, it slows down everyone's speed of transferring information. If you have four or more computers in your home and do a lot of multi-player gaming, you will notice a significant difference between using a hub and a switch.
When connecting several computers, a lot of information traffic is passed back and forth through a hub, sometimes creating information traffic jams. A switch in the network will cut down on the unnecessary information traffic. The switch has the ability to only pass on only the information addressed to that particular computer.
An Ethernet switch divides the network into multiple bridges and assigns each computer it's own Ethernet port. When information is received, the switch sends that information only to the port dedicated to that computer. Multiple connections can occur simultaneously without any information traffic jams.
Switches are considered to have a layer two and above functionality. Layer two switches will handle most networking needs. A router is a layer 3 switch that can communicate between different types of connections and allows your computer to not only connect to other networked computers (LAN), but also to connect to the internet (WAN)
The outside of both hubs and switches look pretty much the same, but their function and cost differ greatly. As expected, an Ethernet switch will cost more than a simple hub. The switch has the added intelligence the hub lacks.
