Appendix B: Wireless Technology; Overview Of Wireless Technology; Terminology; 144 - AMX MVP-9000i-GB Instruction Manual

Appendix B: Wireless Technology

Overview of Wireless Technology

802.11b/2.4 GHz and 802.11a/5 GHz are the two major WLAN standards and both operate using radio frequency (RF)
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technology. Together the two standards are together called WiFi and operate in frequency bands of 2.4 GHz and 5 GHz
respectively.
The 802.11b specification was the first to be finalized and reach the marketplace. The actual throughput obtained from
an 802.11b network will typically be between 4 and 5 Mbps.
Because of the higher frequency (and thus shorter wavelength) that they use, 802.11a signals have a much tougher time
penetrating solid objects like walls, floors, and ceilings. As a result, the price for 802.11a's higher speed is not only a
shorter range but also a weaker and less consistent signal.
802.11a/b/g provides increased bandwidth at 54 Mbps. As part of the IEEE 802.11a/b/g specification, when throughput
cannot be maintained, this card will automatically switch algorithms in order to maintain the highest spread possible at a
given distance. In addition, 802.11a/b/g can also step down to utilize 802.11b algorithms and also maintain a connection
at longer distances.
IP Routing is a wireless routing behavior that is largely dependent on the wired network interface. Although the panel can
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be connected to two networks simultaneously, it may only have one gateway. If the wired network was successfully set up
and a gateway was obtained; then the default route for all network traffic will be via the wired network. In the event that
the wired network was not configured, then the default route for all network traffic will be via the wireless network. The
wired network connection always takes priority.
Example: Imagine a panel connected to the two networks A & B. A is the wired network and B is the wireless network. If the
Master controller is on either of these networks, then it will be reached. However if the Master controller is on a different
network, C, then the gateway determines which network interface (wired or wireless) will be used. If the Master controller
is on network B and the panel is docked, the Master would still be reached through network A, even if the interface is on B.
Access Points (APs) are the cornerstone of any wireless network. An AP acts as a bridge between a wired and wireless
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network. It aggregates the traffic from all wireless clients and forwards it down the network to the switch or router. One AP
may be all that is necessary for a standard installation. However, more APs may be needed, depending on the size of the
installation, its layout, and its construction.
Wireless Equivalent Privacy (WEP) Security is a method by which WLANs protect wireless data streams. A data stream
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encrypted with WEP can still be intercepted or eavesdropped upon, but the encryption makes the data unintelligible to the
interloper. The strength of WEP is measured by the length of the key used to encrypt the data. The longer the key, the
harder it is to crack.
802.11b implementations provided 64-bit and 128-bit WEP keys. This is known respectively as 64-bit and 128-bit WEP
encryption. 64-bit is generally not regarded as adequate security protection. Both key lengths are supported by the
Modero product line. Whichever level of WEP used, using identical settings is crucial (CASE SENSITIVE)--the key length,
and the key itself-- on all devices. Only devices with common WEP settings will be able to communicate. Similarly,
If one device has WEP enabled and another does not, they will not be able to talk to each other.
Although the calculations required to encrypt data with WEP can impact the performance of your wireless network, this
impact is generally only seen when running benchmarks, and is not large enough to be noticeable in the course of normal
network usage.

Terminology

802.1x
IEEE 802.1x is an IEEE standard that is built on the Internet standard EAP (Extensible Authentication Protocol). 802.1x is a
standard for passing EAP messages over either a wired or wireless LAN. Additionally, 802.1x is also responsible for communicating
the method with which APs and wireless users can share and change encryption keys. This continuous key change helps resolve
any major security vulnerabilities native to WEP.

AES

Short for Advanced Encryption Standard, is a cipher currently approved by the NSA to protect US Government documents classified
as Top Secret. The AES cipher is the first cipher protecting Top Secret information available to the general public.

CERTIFICATES (CA)

A certificate can have many forms, but at the most basic level, a certificate is an identity combined with a public key, and then
signed by a certification authority. The certificate authority (CA) is a trusted external third party which "signs" or validates the
certificate. When a certificate has been signed, it gains some cryptographic properties. AMX supports the following security
certificates within three different formats:
PEM (Privacy Enhanced Mail)
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DER (Distinguished Encoding Rules)
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PKCS12 (Public Key Cryptography Standard #12)
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MVP-9000i - Instruction Manual
Appendix B: Wireless Technology

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