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  Networking 101: Served Right

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The Steak

At this time 802.11b is considered the industry standard, it runs at a speed of 11Mb on the 2.4 GHz spectrum, the same as most cordless phones, this makes it prone to interference from other devices however. With a realistic throughput of 2.5-4Mbps, it is fast enough for most network applications and tolerable for file transfers. This speed is still faster than all ISPs so you will notice no difference in your internet transfers but transfers between computers on your network will be much slower compared to 802.11g, 802.11a or wired Ethernet. 802.11b is a half duplex protocol it can send OR receive, but not both at the same time. The range for this type of device is about 250ft indoors. Some people have used directional antennas to get some serious range out of their 802.11b products miles!

A new emerging standard is the 802.11g devices which operate at a maximum of 22Mbps but can communicate at up to 54Mbps, also on the 2.4 GHz spectrum and reverse compatible with 802.11b, this makes it a great choice for anyone. Like 802.11b, 802.11g is subject to the same interference and security issues and also the same range. When an 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. The 802.11g standard has not been widely adopted because of the emergence of 802.11a.

802.11a is a 54Mbps wireless standard that is completely incompatible with 802.11b or g but has a greater overall throughput. 802.11a operates in the 5 GHz frequency range and can transfer data at the rate of 54Mbps!  That is over 4X the transfer rate of 11Mbps 802.11b and although it is another form of Wireless Ethernet, 802.11a is incompatible with 802.11b products because of the different frequencies they operate at. 802.11a network adapters can operate in two modes, infrastructure and ad-hoc. In infrastructure mode, all network adapters talk to each other THROUGH a central 'Access Point'.  This access point grants permission to each device, determines the frequency to communicate on, and relays data between network adapters. Since 802.11a products communicate in the 5 GHz frequency range, they do not cause problems with cordless phones like most 802.11b products do. Unfortunately, 802.11a also has a range limitation in comparison to 802.11b - often 1/3 the range. 802.11a can communicate at a maximum rate of 72Mbps but due to FCC frequency restrictions, it is currently limited to 54Mbps.  If these regulations change, a simple firmware upgrade will update your equipment.

All three of these wireless technologies need what is called an Access Point referred to as an AP. Access points are stand alone devices that can 'bridge' wireless computers to wired Ethernet computers. They may also be built into other devices like network routers, especially in the home consumer market.

Access points come in three varieties: bridge, NAT router and NAT router + bridge.

A bridge type 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 both, 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/DSL routers with wireless.



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