While setting up a network is far simpler today than it was just 10 years ago, it';s still a complex world with an obscure nomenclature developed by engineers who have spent decades huddled in server closets.

But the worldwide market for routers and switches are forecast to grow through 2010 based in part on continued strength in the small business sector, according to research by the Dell'Oro Group, a Redwood Shores, Calif. market research firm specializing in networking and telecommunications. The market for routers is expected to exceed $5 billion this year, while the switches sales are expected to grow to $18 billion by 2010. This growth is largely thanks to the ever-increasing role of computers in businesses of all sorts along with the continual need for them to stay connected.

Given the unlimited value of a computer network to today's small and medium-sized enterprises, and the security implications of connecting your company's infrastructure to something as wild and untamed as the Internet, it&'s important to understand how a network works.

Two important components of a network are: routers and switches. These devices are essential because they enable individual computers and whole networks to talk to each other efficiently.

What is a switch?

A network switch, or bridge, is a specialized device that connects multiple network segments. It's a more modern and efficient form of the ubiquitous (and outdated) network hub. A hub, also known as a repeater, is a simple device that has been used for years to connect all nodes, or computers, on a network to a central location. Each node on a network has a unique hardware address called a MAC address. A hub is known as a repeater because when a packet of data, or frame, is sent through the hub, it is repeated to each and every computer on the network.

This means that if a 1 GB video is sent to one computer through the hub, the file will also be sent to all of the other computers on the hub. This is very inefficient for bandwidth management. "Hubs have two major drawbacks," says Ben deGonzague, a deployment engineer with TopCoder Software, a Glastonbury, Conn.-based software engineering firm. "First, network bandwidth is consumed as each and every frame is sent to all devices on a network. Second, your network is only as fast as the slowest device. Hubs have become obsolete with switching-based networks."

A switch-based network is one that utilizes switches instead of hubs. A switch is a major upgrade to a hub. Instead of sending all network data to each and every network node, the switch will analyze the MAC address and determine where to send the data. Network bandwidth is not wasted by sending every frame to every port.

So when a switch receives data for a file, if it was addressed to one computer it will only be sent there. The other computers on the network wouldn't know about it. This means that the network is now much more efficient, but it's also a step toward being more secure: "Since switches can segregate traffic from different nodes," says deGonzague, "this makes it more difficult for anyone to capture packets on your network."

What is a router?

While switches connect multiple computers, a router is required to connect multiple networks, like your LAN to the Internet. Routers work by storing large tables of networks and addresses, then using algorithms to determine the shortest routes to individual addresses within those networks. In this way efficient routers not only facilitate intra-network communications, but also play a role in overall network performance. delivering the information faster.

While many consumers are familiar with small routers from companies like Linksys, which can be purchased for less than $50 at computer hardware stores, they shouldn't be confused with a proper router for business. "A typical router at home will connect your cable modem or DSL network to your internal network. This is just connecting two different networks. Routers for businesses on the other hand might have to connect several different networks," says deGonzague. Small business routers from vendors like Cisco often include management software, enabling IT staff to better manage network stability and, ultimately, performance.