Choosing Wireless Home Networking Equipment

Access Point Selection

• WPA/WPA2 Enterprise: This business-oriented variant of WPA
provides the ability to use a special 802.1x or RADIUS server
(explained in Chapter 9) to manage users on the network. For
the vast majority of wireless home networkers, this capability is
overkill, but it doesn’t hurt to have it (any WPA/WPA2 Enterprise
certified system also supports WPA/WPA2 Personal).
Other certifications: The Wi-Fi Alliance provides a number of other specialized
certifications that not all Wi-Fi certified gear will have earned,
like the following:
• WMM: Wi-Fi Multimedia certification can be found on a growing
number of audio/video and voice Wi-Fi equipment (these items
are discussed in Chapters 12 and 13, respectively). WMM certified
equipment can provide on your wireless LAN some Quality of
Service (QoS), which can give your voice, video, or audio data
priority over other data being sent across your network. We talk
about WMM where appropriate in Chapters 12 and 13.
• WPS: Wi-Fi Protected Setup certification is increasingly common on
new equipment, but still rather new as we write this. WPS, which
we discuss in detail in Chapter 9, is a user-friendly front end to
WPA2 Personal, and allows you to set up network security simply
by pushing buttons (or entering preassigned PIN codes) on your
AP/router and network clients.
• EAP: Extensible Authentication Protocol is part of the WPA
Enterprise/802.1x system used in business wireless LANs — EAP
provides the mechanism for authenticating users (or confirming
that they are who they say they are). A number of different EAP
types can be used with WPA Enterprise — each type can be certified
by the Wi-Fi Alliance. You don’t need to worry about this
unless you’re building a WPA Enterprise security system for your
network.

Servers,Gateways, Routers, and Switches
DHCP servers
To create an easy-to-use home network, your network should have a Dynamic
Host Configuration Protocol (DHCP) server. A DHCP server dynamically assigns
an IP address to each computer or other device on your network. This function
relieves you from having to keep track of all the devices on the network and
assign addresses to each one manually.
Network addresses are necessary for the computers and other devices on
your network to communicate. Because most networks now use a set of protocols
(Transmission Control Protocol/Internet Protocol, or TCP/IP) with
network addresses (Internet Protocol, or IP, addresses), we refer to network
addresses as IP addresses in this book. In fact, the Internet uses the TCP/IP
protocols, and every computer connected to the Internet must be identified
by an IP address.

NAT and broadband routers

A wireless router is a wireless AP that enables multiple computers to share
the same IP address on the Internet. This fact would seem to be a contradiction
because every computer on the Internet needs its own IP address.
The magic that makes an Internet gateway possible is Network Address
Translation (NAT). Most access points you buy now are wireless gateways.
Vendors sometimes call these wireless routers wireless broadband routers or
perhaps wireless cable/DSL routers. What you’re looking for is the word router
somewhere in the name or description of the device itself. Stand-alone access
points (without the router functionality) usually are called just an access
point, so sometimes it’s easier to look for something not called that!
In addition to providing NAT services, the wireless routers used in home
networks also provide the DHCP service. The router communicates with
each computer or other device on your home network via private IP
addresses — the IP addresses assigned by the DHCP server. (See the section
“DHCP servers,” earlier in this chapter.) However, the router uses a single IP
address — the one assigned by your ISP’s DHCP server — in packets of data
intended for the Internet.

Switches

Wireless routers, available from nearly any manufacturer, include from one to
eight Ethernet ports with which you can connect computers or other devices
via Ethernet cables. These routers are not only wireless APs but are also wired
switches that efficiently enable all the computers on your network to communicate
either wirelessly or over Ethernet cables.
Make sure that the switch ports support at least 100BaseT Ethernet — this is
the 100 Mbps variant of Ethernet. You should also ensure that the switch
supports the full-duplex variant of 100BaseT — meaning that it supports 100
Mbps of data in both directions at the same time. If you’re looking for the ultimate
in performance, you should strongly consider paying a bit more for a
router that supports Gigabit Ethernet (1000BaseT)