Escient FireBall SE-D1, Руководство по запуску

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HOME NETWORKING PRIMER WD005-1-2
12/22/2003
6325 Digital Way Indianapolis, IN 46278 317.616.6789 phone 317.616.6790 fax www.escient.com
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 Ecient products to your Ethernet network
when you can’t run ethernet cables to your equipment.
Access Points
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 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
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.
Security
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 business, 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 bust 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 power.
Encryption
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.