Ethernet is the most popular and considered the networking topology
standard for most computer connections. There have been many kinds
of Ethernet, but the most popular is 10/100Mbps running over copper
twisted pair wires. 100Mbps Ethernet is also called 100baseT and
Note: Older Ethernet standards ran on COAX cable and were referred
to as 10base2 Thin Ethernet and 10base5 Thick Ethernet. Some hubs
still have a coax connector to bridge together twisted pair and
Thin Ethernet networks. A newer Ethernet standard called Gigabit
Ethernet or 1000baseT also can run over copper wire but the required
hubs and switches can be very expensive.
10/100 Ethernet Connections
Connections between 10/100 Ethernet adapters are made using cables
that run to an Ethernet HUB or Switch. Hubs electrically connect
your computers together and switches act like traffic cops making
your network more efficient. When only two computers are present,
a special kind of Ethernet cable can be used called a crossover
10/100 Ethernet cables have 8 wires, of which 4 are used for data.
The other wires are twisted around the data lines for electrical
stability and resistance to electrical interference. The cables
end in RJ-45 connectors that resemble large telephone line connectors.
Two kinds of wiring schemes are available for Ethernet cables.
Patch cables and Crossover cables. Crossover cables are special
because with a single cable, two computers can be directly connected
together without a hub or switch. If a cable does not say crossover,
it is a standard patch cable. If you are connecting computers
to a hub or switch, you need patch cables. There are also different
grades of cable quality. The most common are CAT5, CAT5e and CAT6.
CAT5 is good for most purposes and can transfer data at 100Mbps.
CAT5e is rated for 200Mbps and CAT6 is rated for gigabit Ethernet.
Run CAT5e whenever possible because there is usually not a cost
difference from CAT5 if you look hard enough.
For all twisted pair Ethernet, 100Meters is your maximum distance.
Ethernet to Fiber
Ethernet to Fiber media converters are starting to come down in
price - they can be found for under $150. When 100Meters is not
enough distance, an Ethernet to fiber media converter can be placed
on each end making the maximum distance something like 40Km. Another
use for fiber is electrical insulation. Some people like to run
cables underground between homes. If you run CAT5 cable, the homes
have different 'ground potentials' and you will burn out network
card during any electrical storm. The solution is fiber! Run fiber
between the homes or run a pair of fiber converters on one end
of the cable with a short fiber run. This will electrically separate
the two homes.
Wireless Networking with 802.11b
In 2000, 802.11b became the standard wireless networking technology
for both business and home. The WiFi organization was created
to ensure interoperability between 802.11b products. With a realistic
throughput of 2.5-4Mbps, it is fast enough for most network applications
and tolerable for file transfers. Wireless to Ethernet Bridges
can be used to connect any Ethernet product to your network when
you can’t run cables to your equipment.
An 802.11b wireless network adapter can operate in two modes,
Ad-Hoc and Infrastructure. In infrastructure mode, all your traffic
passes through a wireless ‘access point’. In Ad-hoc
mode your computers talk directly to each other and do not need
an access point at all.
Access point varieties
Access points come in three varieties -- bridge, NAT router and
NAT router+bridge. A bridge connects a wireless network to a wired
network transparently. Communication is possible between both
networks in both directions. A NAT router type routes traffic
from your wireless network to an Ethernet wired network, but it
will not route traffic back. This type can be used to share an
Internet connection. Lastly, there are hybrid NAT router + Bridge
devices that bridge your wired and wireless networks, then route
them both to the Internet using a single IP address. This is good
for sharing an Internet connection when you have both wired and
wireless computers in your home. These are often called Cable
or DSL routers with wireless access points built-in.
Any network adapter coming within range of another 802.11b network
adapter or access point can instantly connect and join the network
unless WEP (Wireless Encryption Protocol) is enabled. WEP is secure
enough for most homes and businesses, but don’t think it
can’t be hacked. There are several flaws in WEP making it
unusable for high security applications. At this point, it takes
some serious hacking abilities to break into a WEP enabled network
so home users should not worry.
WEP and Speed
WEP will slow down your wireless network. Expect a 20-50% reduction
in speed depending on the products you are using. The speed issue
is often the result of an access point without enough processing
Encryption comes in 64bit and 128bit key varieties. All your nodes
must be at the same encryption level with the same key to operate.
40bit and 64bit encryption is the same. it’s just a matter
of how the manufacturer decided to label the product. Often 128bit
cards can often be placed in 40/64bit mode.
802.11b adapters come in two major form factors. PC Cards for
laptops and USB for desktops. In addition, there are PCI adapters
that let you plug a PC Card into a PCI Slot.
A full strength 802.11b signal will get you about 3.5-4.5 Mbps
without WEP enabled. With WEP enabled, expect 2.5-3.5 Mbps. As
you put walls and distance between your wireless adapter and your
access point, your speed will drop. Don’t expect to put
more than a few walls between you and your access point.
802.11b is a half duplex protocol – it can send OR receive,
but not both at the same time. In addition it uses the same 2.4
GHz range as many cordless phones so plenty of opportunity exists
for interference. Use 900Mhz cordless phones if using 802.11b
in the same area.
Distance will very widely depending on which wireless networking
device you are using, what kind of antenna it uses, the construction
materials in your home, electrical interference, and capabilities
of the wireless receiver. Some people have used directional antennas
to get some serious range out of their 802.11b products –
Faster Wireless 802.11g
The 802.11g spec was drafted in Nov of 2001. 802.11g operates
on the same frequency as 802.11b and is backwards compatible.
The planned common implementation of consumer 802.11g devices
operate at a maximum of 22Mbps but can communicate at up to 54Mbps.
802.11g is sometimes called “Turbo Mode” on some 802.11b
cards. Like 802.11b, 802.11g is subject to the same interference
and security issues. It operates at 2.4Ghz and may cause problems
with 2.4Ghz cordless telephones. When a 802.11g product communicates
with an 11Mbps 802.11b product, it drops down to 11Mbps or less
depending on signal strength. In other words, if you purchase
an 802.11g product for use with an 802.11b access point, expect
only 11Mbps.Powerline Networking
Power line networking has existed in a few forms in the past,
the latest specification is called HomePlug and runs at 14Mbps.
HomePlug uses your existing home electrical wiring to transfer
data. HomePlug does not interfere with your existing electrical
equipment or home automation devices like X-10, CEBus, and LONworks.
HomePlug also encrypts all data with 56bit DES encryption to ensure
that your neighbors can not eavesdrop on your network traffic.
Note: encryption is usually not enabled by default and must be
'turned on' using software provided by the device’s manufacturer.
The HomePlug specification incorporates
a technology called PowerPacket. This new technology is what makes
HomePlug different from the old Power line networks. PowerPacket
eliminates noise from electrical appliances like hair driers and
televisions plus it offers security.
Power line network adapters come in PCI and USB versions but are
fairly expensive right now--about $50 to $100 per computer. There
are also Power line to Ethernet bridges and Power line broadband
routers with ethernet bridges built-in, in the same price range.
Alternative Networking Technologies
Alternative networking technologies are often used to supplement
a primary network. They are not as popular as the aforementioned
networks, but are still available. They can be 'bridged' to other
networks to create a single integrated network. You can buy different
network adapters to ‘bridge’ or connect one type of
network to another.
Ethernet: Gigabit - 1000TX
The fastest network technology available to the home or small
business, gigabit Ethernet comes built in to most PC and MAC systems
now. As the name suggests, gigabit Ethernet runs at 1000Mbps.
Wireless 802.11a: 54 Mbps
A new standard for wireless ethernet, 802.11a is incompatible
with 802.11b and g. It does however offer amazing speeds for a
wireless network, but is not as popular as 802.11g
Firewire Networking - 400Mbps
Modern operating systems now support networking over firewire
cables. Most appropriate for short distances, firewire is FAST
and inexpensive to install. Great for transferring huge video
files between computers! 800Mbps firewire is also available on
new Mac systems.
A new ‘personal’ wireless networking technology, Bluetooth
has recently made an appearance. It is easy to implement and will
be VERY inexpensive soon. Because of its low speed (1.5Mbps) it
is not appropriate as a replacement for other networks but IS
valuable for connecting peripherals.
Wireless HomeRF 2.0: 10Mbps
Developed to compete with 802.11b, HomeRF made a brief appearance
and died off. Siemens and Proxim were the main supporters.
HomePNA 2.0 (Phone Line): 10Mbps
HPNA, PhoneLine or HomePNA networking works over the existing
copper telephone wires in your home without interfering with voice
or DSL communications. HomePNA 3.0 will push the speed up to 100Mbps
when it comes out.