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Running multiple computers at one location connected to
the Internet is becoming the standard,
even in the home.
I know lots of people who are trying to figure out what
to do, how to do it and
what to do when it doesn't work.
- To
help you understand your options, and see where the
future might be, I decided to show you what
most
homes would have. I'm not endorsing any specific
vendor - I haven't done an exhaustive search,
there
are always newer devices available, etc., but I
think being specific about one configuration
that a
person actually is using helps the most.
Overview
Here is a
diagram of a typical setup. A cable modem connected me to
the Internet and a router with 4 ports.
There's usually one
or more PC's connected to the router by 10BaseT wire and a
laptop and/or an awkwardly
located wireless desktop
connected to the router either by a wire and a standard
10BaseT LAN card or to
the wireless access point via a
pc-card and a USB networking device ...
Let me walk
through this in detail.
Cable Modem
Most have a
cable or DSL modem from a local provider. Your provider
claims 1.5Mbit per second maximum
300Kb maximum (you can get
higher bursts at off-peak hours, half that when it's busy).
They charge around $40 a month.
The cable
modem gives you a place to plug in a LAN cable with an RJ-45
connector just like any 10BaseT
Ethernet port on a LAN. The
cable modem expects a single network interface adapter with
a particular (MAC)
address on the other end of the LAN cable
you plug into it. The cable modem makes that single LAN
connection appear to the Internet as a single IP address.
Normally that adapter is in a single PC.
Router/Switch
The router has
such an adapter to connect to the cable modem, but it also
has one or more other places to
plug in other LAN
connections (it is a network switch with respect to those
other cables). The router gives
devices connected into its
LAN connections their own individual IP addresses (local
ones) and translates them
in a way so as to share the single
external IP address that is available through the cable
modem. This is called
Network Address Translation (NAT). In
the process of doing this, most home/SOHO routers like the
one I have
also act as firewalls controlling access from the
Internet outside to the network inside.
There are many
different makes, but illustrated here is a Linksys BEFSR41
4-Port Cable/DSL Router.
Here's what it looks like on the
floor under a PC with the power and other cables coming out
of it:
You can
configure this router by connecting a PC to it with a
10BaseT connector and using a browser
displaying a
particular URL. You can set all sorts of parameters. The
instructions tell you how to set it up.
(The defaults are
fine for most everything.)
When you
configure your router you may find out that you can specify
that it pretend to your cable modem
that it's any MAC
address you want. This lets you add the router to your
computer setup without needing
to tell your cable company
you have a new adapter address - you just make the router
pretend it's your
PC's address. (The router uses a
different, unique address to your inside network.)
The
router/switch can control a LAN in your home/office. You
just plug computers into it using 10BaseT
cables and they
are connected to the Internet for browsing, email, etc. Some
bring their laptops home
from work or a trip and plug it in
and things seem to just work with no new settings.
Since the
computers connected to it are on a common LAN, you can share
printers, hard-drives,
zip drives, etc., just like any other
LAN.
Until now most
folks had used Windows' Internet Connection Sharing for
networking and it was a
nightmare to configure. That's
something implemented in software built into Windows 98.
(You can add it by going to the Control Panel's Add/Remove
Programs section, clicking on the Windows
Setup tab, and
looking at the Details of Internet Tools to make sure that
Internet Connection
Sharing is installed.) Windows Internet
Connection Sharing requires you to have two network cards
in
your computer (or a dial-up connection and a LAN card). It
connects to the Internet on one and to
a LAN on the other.
It only works when the connected computer is running, and
most people found
that it slowed overall connections some
with its overhead. The router is a much cleaner solution,
and usually has a built-in hardware firewall for added
protection and eliminating the need for a software firewall.
Wireless: 802.11b/g
While many
offices are fully wired, most homes are not. Rather than
mess up your walls and spend hours
pulling cables or pay an
electrician lots of money, you may decide to use wireless.
A type of
wireless system that is extremely popular is called 802.11g
or Wi-Fi. It runs up to 154 Mb/second,
about as fast as a
normal 10BaseT LAN and much faster than a 1.5Mb/second
(maximum) cable modem.
You got to try using that type of
system at the PC Forum and Agenda conferences, and at Fall
Comdex
2006 that it is becoming a standard of choice all
over the place in business, education, and the home.
Walt
Mossberg recommended it in
one of his columns. Microsoft and Mobilestar are
putting it in Starbucks.
Wayport is putting it in airport lounges and
hotels around the USA. You should decide to buy equipment
that conforms to that standard. The current standard is
802.11g, which is 15 times faster than that.
802.11b/g
sounds like a very techie term, but it isn't. It's just the
name of a particular specification for
wireless networking
from a group that likes to use numbers for names, the
IEEE Standards Association.
They have lots of
specifications with numbers for names. "647" is the Standard
Specification Format Guide
and Test Procedure for
Single-Axis Laser Gyros. "802"
is the Local Area and Metropolitan Area Networks
standards
(LAN/WAN). Within that, "802.3" is Ethernet, "802.5" is
Token Ring, etc., and "802.11" is
Wireless LAN. "802.11b/g"
is a particular version referring to 2.4GHz radio using
Direct Sequence Spread
Spectrum and CSMA/CA that runs at up
to 154 Mb/second. To learn more about 802.11b/g, you can
read
a
3Com whitepaper about 802.11b or take a look at
the Wireless Ethernet Compatibility Alliance
web site
(especially their
whitepapers and
glossary). That Alliance is trying to get the
name Wi-Fi accepted as a
common term for 802.11b (and a
trademark).
Wireless Access Adapters
After buying
your wireless 802.11g router, to make any part of your LAN
wireless you need what's called a
Wireless Adapter
for each of your computers. Most common are the pccard for
laptops, wireless NIC's for
desktop and wireless USB adapter
in awkward areas. The wireless adapter connects to your LAN
like any
other device and then lets any computer connected
to it wirelessly act as if it were on the same LAN.
Here's a
picture of a typical unit (a Linksys WAP11):
You configure
the settings in the unit by either connecting a computer to
it with a USB connector (some
other vendors use serial) or
on the local LAN with a utility they give you. The default
configuration worked
fine, though you can end up making some
modifications to make the system more secure. You need to
set
the name of your ESSID (your logical wireless LAN). This
can be most any name or you can keep the
default (usually
that default "linksys" or whatever router you have --
surprise!). You should enable
encryption (Wire Equivalent
Privacy, or WEP) by setting a series of keys. In some units
you type in
a phrase and it uses that to give you a series
of hex digits that make up the key. It takes a couple of
minutes to configure.
Wireless Adapter Types
To connect
wirelessly, your PC or laptop needs a wireless adapter.
Typical is a 3Com Wireless AirConnect
PC card. It is a
normal PCMCIA Type-II card that goes into the slot in you
laptop just like a LAN card.
It may have an antenna that
sticks out:
You install
the PC card like any other PC card. It needs a driver. In
this case after after getting the LAN
set up you should
download the latest drivers and firmware for the card from
the Manufacturers web site
and upgraded your system.
When you configure the driver you type in the ESSID
(Wireless LAN Service
Area name) and the encryption key
information. That's it. Everything else seems to just work -
mostly!
Your PC card
may come with some utilities, such as one that displays the
signal strength in real time.
Here is a picture of that
utility at one point when the signal wasn't so good and it
automatically slowed
down to 5.5Mb/second. Next to it is a
picture taken outside of a laptop over 150 feet away from
the house
(the wireless access point is next to an outside
wall, inside the house). You can see a website on the screen
(this wireless stuff really does work!):
There are
adapters for desktop PCs that let you use the wireless PC
cards. You plug the adapter boards
into a PCI slot and then
plug the same type of card you use on a laptop into that
board. There's also
USB devices available as well.
Realities of wireless
While it all
generally works, you have to remember that this is
wireless, just like cell phones, walkie talkies,
etc...
Line-of-sight outdoors can work quite a distance, but
indoors, with walls and electrical devices, you
get more
interference and much less obvious coverage patterns. (For
example, the area on the other side
of a wall behind bricks
can be a dead zone, just 10 feet from away reception can be
just fine.) Also, other
2.4GHz devices, like some
cordless phones and the upcoming Bluetooth devices, can
cause temporary
gaps in operation. Periodically you may have
to click on a link a second time. You can also optimize the
location of your router and/or wireless access point. Higher
is better I hear. Still, it is pretty useful.
It's great
checking email along with the newspaper at breakfast without
any wires. If you see something
you need to print out, just
click on "Print" and soon you'll hear the faint sounds of
the printer in the other
room on another PC doing its thing.
Some hints:
Folks who have their Internet access coming into the
basement and therefore put their wireless
access point in
the basement report poor reception in other parts of the
house. Some vendors' access points
are more effective than
others (I don't know which), so ask around. Within a house,
if you don't have great
placement, think of it like
shouting: voices don't carry through too many walls, and
local wireless is like
shouting. Remember what cell phone
service is like in many buildings: Some rooms are dead
zones, other
places are OK. Building materials and antenna
placement matter. As an example, read about David
Coursey's
struggles with 802.11b in his home in his
AnchorDesk essay.
Setting it all up
Setting this
all up is not very hard - no more so than most any other
multi-part PC accessory setup,
like a PDA with
synchronization or a peripheral with special software. Just
don't forget to buy the cables
and have enough places to
plug things in...
Approximate
cost today: Wireless 4 port 802.11g Router - $60 to $150, Wireless
Access Point - $160 to
several hundred, Wireless PC card/s
for your laptop/s - $60 to $180 each (most new laptops come
with
built-in WiFi these days), desktop PC PCI wireless
adapter/s - $60 to $110 (you need to add one of the
cards to
each desktop computer). There are various combination
devices (router/wireless access points)
and bundles
(including some cards) available so shop around for
bargains. Several companies are making
these, with new ones
announced all the time. Prices have really dropped in the
past year. Don't buy
802.11b at this point.
802.11g is very cheap and much faster & more reliable.
I hope this
information helps you decide what to do for your home
network setup.
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