Home Networking: Routers, Switches and Hubs - What's the Difference?

If you're building a home network, you have probably looked at routers to connect your computers. Before you buy one, though, it's important to understand whether you really need a router. There are similar devices, called hubs and switches, that may fit your needs and save you money. So what are the differences?

Routers are advanced networking devices. They feature services like Dynamic Host Configuration Protocol (DHCP) and Network Address Translation (NAT). Routers can connect network segments that use different technologies, like Token Ring, Ethernet and ARCnet.

But unless your kids just have to have that Token Ring topology, you won't need all that. Most ISPs already have DCHP, and if your home PCs are firewalled, you won't really need NAT either. Clearly, routers are for more complex networks than a few home PCs.

A good solution for your home network is a simple hub. Installing one is the same as installing a router, but without all the configuration. Set up your computers to the same workgroup, plug in the machines and broadband modem, plug in the power, and start up your PCs.

Hubs are simple and not very "intelligent" -- when a machine wants to transmit data, the hub sends a message to every machine on the network. Only the intended recipient actually gets the data; the rest ignore it. With three or four machines this isn't a problem, but hubs can really slow down larger networks.

Switches are the "in-between" solution. Neither as smart as a router nor as dumb as a hub, a switch gives small networks a boost in performance. And unlike hubs, switches can work well for larger network segments as well.

At first, a switch works just like a hub -- it sends messages to every recipient. But switches work on a higher level of networking than hubs, called the Data Link layer. They can learn which PC a message is going to, based on both the IP and MAC addresses of the recipient, and will only send future messages to the correct computer. This creates much less network traffic than a hub.

If you're especially concerned about privacy, and want the extra level of security a router can give you, by all means buy one. But if you have a good software firewall, and you only have a few computers to connect, look into buying a switch or a hub.