A | The Business Case for Enterprise-Class Wireless LANs

AAA: Authentication, authorization, accounting. This term is used to describe a generic system or solution that ensures that only authenticated users or devices gain access to the network in a recorded and auditable manner. This framework is usually provided by a AAA server. Examples include Microsoft Active Directory servers, RADIUS servers, and Cisco Access Control Servers. The user or device must supply a set of credentials to the AAA server, which, upon validation, approves access to the network and records the transaction. Some AAA services also monitor and record user activity and what services are accessed.

access layer switch: Access layer switches are the wired devices that provide connectivity to your wired network. Access points are usually connected to access layer switches. Also known as network edge switches.

ACL: Access control list. A managed list that defines network traffic controls by protocol, port, address, or time. The ACL defines the traffic that is permitted and the traffic that is denied.

ad-hoc network: In WLAN terms, an ad-hoc network is one in which two or more WLAN clients communicate with each other directly, without the use of an access point (AP). Ad-hoc networks are usually used by small, home, or SOHO networks on a peer-to-peer basis without a central communication hub.

AES: Advanced Encryption Standard, based upon a symmetric encryption algorithm. AES provides significantly more security than WEP and forms part of the 802.11i standard. It is also a Federal Information Processing Standards (FIPS)-approved algorithm. The AES, documented in FIPS Publication 197, specifies a symmetric encryption algorithm for use by organizations to protect sensitive information. See also 802.11i; CCMP.

AP: Usually a hardware device that acts as a communication hub for wireless clients, linking 802.11 stations to a wired backbone network. Each access point effectively creates a radio cell through which all traffic must pass. Access points are often abbreviated to AP in industry literature.

association: The relationship established between wireless clients and access points. Association denotes a MAC layer connection between the client and the AP.

attenuation: The loss of signal strength when radiated due to environmental factors, such as walls, furniture, building material, and so on. Attenuation is also caused by long lengths of transmission cable.

authenticator: A device that authenticates a client. In EAP-based wireless networks, the access point usually acts as an authenticator by passing the request upstream to a AAA server for validation. Upon successful validation of the user's or device's credentials, the authenticator permits it access to the network.