Suppose that you want to share a digital subscriber line (DSL) or cable modem with all the computers on your wireless network. Suppose that you have two computers on the first floor, and you're dying to do work on your wireless-equipped laptop while you relax in your bed (on the second floor), but the signal doesn't reach. Don't worry; manufacturers have come up with some clever hardware devices to overcome your problems.
Wireless routers
By definition, a router transfers data between multiple networks. In home networks, you can use a router to move data from one network (your home network) to another network (the Internet). This is how you share a DSL or cable modem Internet connection with all the computers on the network.
A wireless router (frequently called a wireless local-area network [WLAN] router) has an antenna that captures the signals from all the computers on your wireless network, effectively acting like a hub or a switch.
The router also has ports for Ethernet connections. For most wireless home networks, the Ethernet port is used to connect the DSL or cable modem to the router. However, you can also use those ports as a hub for an Ethernet network, essentially combining three networks: the wireless network, an Ethernet network, and the Internet.
A router also provides IP addresses to the computers on the local network. Because it does so, it's acting as a Dynamic Host Configuration Protocol (DHCP) server. The router provides a single point of communication with your DSL or cable Internet service provider (ISP). (The ISP sees only the router, not the individual computers that are on the network.) Some routers even come with built-in firewall capabilities.
WLAN routers are easy to install and configure. You must physically connect the unit to a DSL or cable modem using Ethernet cable. The port is usually labeled WAN (for wide-area network) or Ethernet. The manufacturer's instructions can help you make the connections.
Wireless access points
Unlike cabled networks, wireless networks don't need a hub or switch. If all you want to do is network a group of wireless computers, you just purchase a wireless adapter for each computer, put them all within 300 feet of each other, and voilà! - instant network.
But what if you already have an existing cabled network? For example, suppose that you have two computers in your den connected to each other with network cable, but you want to link up a computer in your bedroom without pulling cable through the attic.
That's where a wireless access point, also known as a WAP, comes in. It's a box that has an antenna (or pair of antennae) and an RJ-45 Ethernet port. You just plug it into a network cable and then plug the other end of the cable into a hub or switch, and your wireless network should be able to connect to your cabled network. A WAP actually performs two functions.
- It acts as a central connection point for all of your computers that have wireless network adapters. In effect, the WAP performs the same function that a hub or switch performs for a wired network.
- It links your wireless network to your existing wired network so that your wired computer and your wireless computers get along like one big happy family.
Wireless access points are sometimes just called access points, or APs.
Configuring a wireless access point
The physical setup for a wireless access point is pretty simple: You take it out of the box, put it on a shelf or on top of a bookcase near a network jack and a power outlet, plug in the power cable, and plug in the network cable.
The software configuration for an access point is slightly more involved and is usually done via a Web interface. To get to the configuration page for the access point, you need to know the access point's IP address. Then, you just type that address into the address bar of a browser from any computer on the network.
A device's configuration page typically offers the following configuration options that are related to the wireless access point functions of the device. Although the options given here are specific to a particular device, most access points have configuration options similar to these:
- Enable/Disable: Enables or disables the device's wireless-access-point functions.
- SSID: The Service Set Identifier used to identify the network. Most access points have well-known defaults. You can talk yourself into thinking that your network is more secure by changing the SSID from the default to something more obscure, but in reality, that protects you only from first-grade hackers. By the time most hackers get into the second grade, they learn that even the most obscure SSID is easy to get around. So it's best that you leave the SSID at the default and apply better security measures, as described in the next section.
- Allow broadcast SSID to associate? Disables the access point's periodic broadcast of the SSID. Normally, the access point regularly broadcasts its SSID so that wireless devices that come within range can detect the network and join in. For a more secure network, you can disable this function. Then, a wireless client must already know the network's SSID in order to join the network.
- Channel: Lets you select one of 11 channels on which to broadcast. All the access points and computers in the wireless network should use the same channel. If you find that your network is frequently losing connections, try switching to another channel. You may be experiencing interference from a cordless phone or other wireless device operating on the same channel.
- WEP - Mandatory or Disable: Lets you use a security protocol called wired-equivalent privacy.
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