Romney BakeBrian PetersonClay Stephens

Michael Hatheway

OutlineIntroductionTopologyAdvantages/DisadvantagesHardwareA, B, G, N ComparisonMedia Access Controls/Data TransmissionSecurity TypesRouter ConfigurationQuestions

Introduction & HistoryWireless connections were originally

developed for mobile computing devices, such as laptops, but is now increasingly used for more services, including Internet and VoIP phone access and basic connectivity of consumer electronics such as televisions and DVD players.

First Wireless LAN developed in 1971, called ALOHANET.

TopologyInternetInternet

AdvantagesAdvantagesNo cables (Outdoor uses)MobilityWidely available productsGlobal set of standardsAvailable in more than 300,000 hot spotsWPA and WPA2 securitiesCheaper/Comparable prices

Drains batteries on laptopsSecurity issuesDefault settings for access points and routersPotential interoperability between brandsOften slower than wired connectionsLimited range

Disadvantages

HardwareAccess Point (AP)Connects a group of wireless devices to an

adjacent wired LANRelays data between connected wireless

devices in addition to a (usually) single connected wired device

Wireless Adapter (WNIC)Allows a device to connect to a wireless

networkConnects by either PCI, USB, PCMCIA

Wireless RouterAllows wired and wireless ethernet LAN

devices to connect to a (usually) single WAN device such as cable modem or DSL modem

allows all three devices (mainly the access point and router) to be configured through one central utility

Range ExtenderExtends the range of an existing wireless

networkAllows signal area to reach around barriers

such as those created in L-shaped corridorsIncrease in latency

802.11a, b, g, n

Media Access ControlUses Carrier Sense Multiple Access with

Collision Avoidance (CSMA/CA), similar to CSMA/CD in wired Ethernet

Computers listen before transmitting, if no one else is transmitting, they transmit

Data TransmissionDistributed Coordination FunctionRelies on computers to physically listen

before transmittingStop and Wait ARQPoint Coordination FunctionComputer must send Request To Transmit to

Access Point firstThe Clear To Transmit is granted for

requesting computer for specific time period on the circuit

Works well with high traffic networks

Security TypesService Set Identifier (SSID)Code attached to all packets on a wireless

network to identify each packet as part of that network

Code is a case sensitive text string which consists of a maximum of 32 alphanumeric characters

Minimum security

Wired Equivalent Privacy (WEP)Provide comparable confidentiality to a

traditional wired networkWEP key can be cracked with readily

available software in two minutes or less Easy to share key for access

Extensible Authentication Protocol (EAP)Generates WEP keys automaticallyUser login to serverAfter login sever will generate WEP key for

the sessionEasy to break by professional hackers

Wi-Fi Protected Access (WPA and WPA2)Intended as an intermediate measure to take

the place of WEP while 802.11i was preparedDesigned to work with all wireless network

interface cards, but not necessarily with first generation wireless access points

WPA2 implements the full standard, but will not work with some older network cards

Not selected by default

Questions?