User's Guide

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TLS: transport layer security protocol. An authentication and encryption protocol that is the
successor to the Secure Sockets Layer (SSL) protocol for private transmission over the Internet.
Defined in RFC 2246, TLS provides mutual authentication with non-repudiation, encryption,
algorithm negotiation, secure key derivation, and message integrity checking. TLS has been
adapted for use in wireless LANs (WLANs) and is used widely in IEEE 802.1X authentication.
TTLS: Tunneled Transport Layer Security (TTLS) sub-protocol. An Extensible Authentication
Protocol (EAP) sub-protocol developed by Funk Software, Inc. for 802.1X authentication.
TTLS uses a combination of certificate and password challenge and response for authentication.
The entire EAP sub-protocol exchange of attribute-value pairs takes place inside an encrypted
transport layer security (TLS) tunnel. TTLS supports authentication methods defined by EAP,
as well as the older Challenge Handshake Authentication Protocol (CHAP), Password
Authentication Protocol (PAP), Microsoft CHAP (MS-CHAP), and MS-CHAPV2. Compare
EAP-TLS; PEAP.
twisted-pair wire: Type of medium using metallic type conductors twisted together to provide
a path for current flow. The wire in this medium is twisted in pairs to minimize the
electromagnetic interference between one pair and another.
UDP: User Data Protocol. A connectionless protocol that works at the OSI transport layer.
UDP provides datagram transport but does not acknowledge their receipt.
VLAN: virtual LAN. A group of devices that communicate as a single network, even though
they are physically located on different LAN segments. Because VLANs are based on logical
rather than physical connections, they are extremely flexible. A device that is moved to another
location can remain on the same VLAN without any hardware reconfiguration.
VoIP: voice over IP. The ability of an IP network to carry telephone voice signals as IP packets
in compliance with International Telecommunications Union Telecommunication
Standardization Sector (ITU-T) specification H.323. VoIP enables a router to transmit
telephone calls and faxes over the Internet with no loss in functionality, reliability, or voice
quality.
VPN: virtual private network. A virtual private network (VPN) is a way to use a public
telecommunication infrastructure, such as the Internet, to provide remote offices or individual
users with secure access to their organization's network. A VPN works by using the shared
public infrastructure while maintaining privacy through security procedures and tunneling
protocols such as the Layer Two Tunneling Protocol (L2TP). In effect, the protocols, by
encrypting data at the sending end and decrypting it at the receiving end, send the data through a
“tunnel” that cannot be “entered” by data that is not properly encrypted.
WAN: wide area network. A computer network that is geographically dispersed. Commonly, a
WAN comprises two or more inter-connected LANs. The Internet is the world’s largest WAN.
According to the IEEE, WANs “interconnect facilities in different parts of a country or of the
world.”
WECA: Wireless Ethernet Compatibility Alliance. See Wi-Fi Alliance.