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names relate to the two primary ways by which data is carried on the
Internet, and you might have to set up port forwarding for both TCP and UDP
ports, depending upon the application.

Every router or access point will have its own unique system for configuring
port forwarding. Generally speaking, you™ll find the port forwarding section of
the configuration program, and simply type the port numbers you want to
open up into a text box on the screen. For example, Figure 12-3 shows port
forwarding being configured on a Siemens SpeedStream router/access point.
242 Part IV: Using a Wireless Network

As we mention earlier, ports are assigned specific numbers. And to get some
gaming applications to work properly, you™ll need to open (assign) port for-
warding for a pretty big range of port numbers. The best way to find out
which ports need to be opened is to read the manual or search the Web page
of the game software vendor. You can also find a relatively comprehensive list
online at practicallynetworked.com/sharing/app_port_list.htm.




Figure 12-3:
Setting up
port
forwarding.



If your router is UPnP-enabled (Universal Plug and Play, a system developed
by Microsoft and others, that ” among other things ” automatically config-
ures port forwarding for you) and the PC game that you™re using uses
Microsoft™s DirectX gaming, the router and the game should be able to talk to
each other and automatically set up the appropriate port forwarding. Just
make sure that you enable UPnP in your router™s configuration system ” this
will usually be a check box in the router™s configuration program.
243
Chapter 12: Gaming over a Wireless Home Network


Setting Up a Demilitarized Zone (DMZ)
If you need to do some special port forwarding and router tweaking to get
your games working, you might find that you™re spending entirely too much
time getting it all up and running. Or you might find that you open up what
should be the right ports ” according to the game developer ” and that
things still just don™t seem to be working correctly. It happens ” not all
routers are equally good at implementing port forwarding.

Here™s another approach that you can take ” setting up a demilitarized zone
(DMZ). This term has been appropriated from the military (think the North/
South Korean border) by way of the business networking world, where DMZs
are used for devices such as Web servers within corporate networks. In a
home network, a DMZ is a virtual portion of your network that™s completely
outside of your firewall. In other words, a computer or device connected to
your DMZ will accept any and all incoming connections ” your NAT router
will forward all incoming connections (on any port) to the computer con-
nected to the DMZ. You don™t need to configure special ports for specific
games because everything will be forwarded to the computer or device
which you have placed “on the DMZ.”

Most home routers that we know of will set up a DMZ for only one of your
networked devices, so this approach might not work for you if you™ve got two
gaming PCs connected to the Internet. However, for most people, a DMZ will
do the trick.

Although setting up a DMZ is perhaps easier to do than configuring port for-
warding, it comes with bigger security risks. If you set up port forwarding,
you lessen the security of the computer that the ports are being forwarded
to . . . but if you put that computer on the DMZ, you™ve basically removed all
the firewall features of your router from that computer. Be judicious when
using a DMZ. If you™ve got a computer dedicated only to gaming, a game con-
sole, or a kid™s computer that doesn™t have any important personal files con-
figured to be on your DMZ, you™ll probably be okay. If you™re gaming on your
work computer ” the one with all the classified work documents and your
downloaded credit card statements ” you might want to think twice about
setting up a DMZ.

Depending on the individual router configuration program that comes with
your preferred brand of router, setting up a DMZ is really typically quite simple.
Figure 12-4 shows a DMZ being set up on a Siemens SpeedStream router/access
point. It™s a dead-simple process. In most cases, you need only to mark a check
box in the router configuration program to turn on the DMZ and then use a
pull-down menu to select the computer that you want on the DMZ.
244 Part IV: Using a Wireless Network




Figure 12-4:
Setting up a
DMZ.
Chapter 13
Networking Your Entertainment
Center
In This Chapter
Buying audio/video (A/V) gear with wireless inboard
Plugging into wireless with wireless A/V adapters
Understanding your home theater PC options




W ithout doubt, the most significant news in wireless home networking ”
outside of the general price drops that are driving growth in the
industry ” is the movement of the 802.11-based networking outside of the
realm of computers and into the realm of entertainment.

The linkage of the two environments really yields the best of both possible
worlds. You can use your hard drive on your PC to store audio and video
tracks for playback on your TV and through your stereo. You can stream
movies from the Internet and play them on your TV. You can take pictures
with your digital camera, load them on your PC, and view them on your TV.
You get the picture (oops, pun).

You will simply not believe how much the ability to link the home entertain-
ment center with the PC is going to affect your computing and entertainment
experience. It could affect which PC you buy. For example, Microsoft has
teamed up with leading hardware manufacturers such as Hewlett-Packard
(HP) and Gateway to offer Windows XP Media Center Edition PCs, designed
to power your home entertainment system (it™s really too irresistible). It
could affect how you rent movies ” why go all the way to Blockbuster when
you can just download a movie over the Internet from Movielink (www.movie
link.com) with a single click? It could even affect how you watch your
favorite shows because with PC-based personal video recorders (PVRs), you
can record the shows that you want to watch . . . but always miss because you
could never figure out how to record on the VCR. Whew. That™s some change.
246 Part IV: Using a Wireless Network

In this chapter, we expose you to some of the ways wireless home networking
is enabling this revolution toward a linked TV/PC world. You™re going to find
that a lot of what we talk about throughout the book will serve as the perfect
foundation for linking PCs and audio/video systems.

You might be thinking, “Whoa, wait a minute, I thought wireless was just for
data. Are you telling me that I need to move my PC to my living room and put
it next to my TV?” Well, rest assured; we™re not suggesting that, although you
might find yourself putting a PC near your TV sometime soon. You could
indeed put your PC next to your TV, link it with a video cable, and run your
interconnection to the living room. But if that™s your only PC and your wife
wants to watch the latest basketball game, you might find it hard to do your
work!

The revolution that we™re talking about ” and are just getting started with in
this chapter and the ones that follow ” is the whole home wireless revolu-
tion, where that powerful data network that you install for your PCs to talk to
one another and the Internet can also talk to lots of other things in your
home. You™ll hear us talk a lot about your whole home audio network or a
whole home video network. That™s our code for “you can hear (view) it
throughout the house.” You built that wireless network (in Part III), and now
other devices will come and use it. And coming they are, indeed. By the
boxful. So be prepared to hear about all these great devices ” things that
you use every day, such as your stereo, refrigerator, and car ” that want to
hop onboard your home wireless highway.




Wirelessly Enabling Your Home
Entertainment System
If you™re like most of us, your home entertainment system probably consists
of a TV, a stereo receiver, some components (like a record player, tape deck,
or CD/DVD player), and a few speakers. For most parties, this is enough to
make for a memorable evening!

And, if you™re like most of us, you have a jumble of wires linking all this
audio/visual (A/V) gear together. The mere thought of adding more wiring to
the system ” especially, say, to link your receiver to your computer to play
some MP3s ” is going to be a bit much.

We™ve got some good news for you. Regardless of whether you have a $250
television set or a $25,000 home theater, you can wirelessly enable almost
any type of A/V gear that you™ve got. Before we get into the specific options
on the market today, we need to discuss at a high level the wireless band-
width requirements for the two major applications for your entertainment
system: audio and video. Talking in general terms about this is okay because
247
Chapter 13: Networking Your Entertainment Center

the differences among the bandwidth options are fairly great (so applications
fall into clear camps), and we believe that most access points (APs) are
moving toward 802.11a/g dual-mode designs, which is more than enough to
handle your video and audio needs.

Here are the two predominant ways that audio and video files are handled
with your entertainment/PC combo:

Streaming: The file is played on your PC and sent via a continuous
signal to your stereo for live playback.
File transfer: The file is sent from your PC to your stereo system compo-
nentry, where it™s stored for later playback.

These two applications are very different. The big issue here is where the file
is played from. If it™s played on the PC, for instance, it™s streamed to the
stereo for speaker amplification. If it™s played on a source stereo system com-
ponent, you just need to transfer the file. The wireless requirements are quite
different.

With file transfer, a lot of transmissions take place in the background. For
instance, many audio programs allow for automatic synchronization between
file repositories, which can be scheduled during off hours to minimize the
impact on your network traffic when you™re using your home network. And in
these cases, you™re not as concerned with how long it takes as you would be
if you were watching or listening to it live while it plays.

However, a streaming application is very sensitive to network delays and lost
data packets. You tend to notice a bad picture pretty quickly. Also, with a file
transfer, any lost data can be retransmitted when its loss was detected. But
with streaming video and audio, you need to get the packets right the first
time because most of the transmission protocols don™t even allow for retrans-
mission even if you wanted to. You just get clipped and delayed sound, which
sounds bad.

A good-quality 802.11b signal is fine in most instances for audio or video file
transfers and is also fine for audio streaming. Whether it™s okay for video
streaming depends a lot on how the video was encoded and how big the file
is. The larger the file size for the same amount of running time, the larger the
bandwidth that™s required to transmit it for steady video performance. As a
result, people tend to talk about 802.11g and 802.11a protocols for video
simply because a lot of available bandwidth exists for any problems that
might occur when sending the data over the airwaves.

In general, here are four generic ways that you can wirelessly enable your A/V
system, each somewhat dependent upon where the source content resides.
248 Part IV: Using a Wireless Network




Getting to the (access) point
Your wireless signal degrades the farther that There™s no good absolute definition of what
you get from your access point, regardless of constitutes a good-quality signal; but for our
which protocol you™re using. Thus, you might purposes here, it means that the signal is con-
have a great signal near your AP, a pretty good sistent (not varying up and down), and it has at
signal 30“50 feet away, and an increasingly least enough throughput to be able to match the
poorer signal as you get farther and farther bandwidth of the source signal. So if you™re
away. The quality of signal isn™t measured just streaming a 196 Kbps MP3 file, you want to
in speed but also in the strength of the signal so make sure that you at least have that much
that the data packets ” whether carrying throughput available on a consistent basis for
voice, data, video, audio, or whatever ” are that streaming file. In most instances, when
received and understood the first time by the streaming content from the Internet, your wire-
recipient. (Check out Chapters 4 and 5 for more less network speeds will exceed that of your
info about choosing an AP and where to place Internet connection, so your wireless connec-
it in your home for best performance.) tion probably won™t be the bottleneck.




If the source content resides in the entertainment center:

Buy wirelessly functional equipment. Some gear comes with wireless
inboard. For example, Motorola makes the simplefi (www.motorola.
com/simplefi), which is a wireless, digital audio receiver that enables
you to stream audio from your PC or the Internet (through your broad-
band connection) directly to your home stereo. You just need to provide
such equipment with the right Service Set Identifier (SSID) and Wired
Equivalent Privacy (WEP) settings, and it™s on your home wireless net-
work. (Chapters 6, 7, and 8 cover SSID; Chapter 10 has the scoop on WEP.)
This typically gives the equipment access to the Internet and users
remote access to the device itself over these Internet connections. (In
the next section, we introduce you to some of the ways that present
entertainment gear is getting wirelessly enabled.)
Buy a wireless adapter or bridge. Some A/V equipment is network
enabled (meaning that it has some basic network interface capability
such as an Ethernet or a Universal Serial Bus [USB] port) but lacks wire-
less functionality. In these instances, you can buy a wireless adapter to
interface with that port to get the device on the home network. These
typically have RCA jacks on one end of the wireless connection and
Ethernet connections on the other. A wireless bridge is a perfect way to
get it online. Gaming equipment, which we cover in detail in Chapter 12,
commonly has an Ethernet port but no wireless capability; wireless
bridges are perfect to allow multiplayer gaming over the Internet.

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