CIT 1100

In this chapter you will learn how to:  Describe the basics of wireless networking  Explain the differences between wireless networking standards  Configure wireless networks

A wireless network eliminates the need for network cabling to connect PCs to one another  Instead of a physical set of wires, wireless networks use radio waves to communicate  The wireless radio wave networks you'll be supporting are those based on the most common implementation of the IEEE wireless Ethernet standard (Wi-Fi) and those based on Bluetooth technology

Wireless networking capabilities of one form or another are built into many modern computing devices  Wireless Ethernet and Bluetooth capabilities are available as integrated components, or they can easily be added using PCI or PCie  You can also add wireless network capabilities using an external USB wireless NIC cards

Wireless NICs aren't limited to PCs Smartphones can have built-in wireless

To extend the capabilities of a wireless Ethernet network, such as by connecting to a wired network or by sharing a high-speed Internet connection, you need a Wireless Access Point  A WAP centrally connects wireless network nodes the same way that a network hub or switch connects wired PCs  A WAP centrally connects wireless network nodes the same way that a network hub or switch connects wired PCs

Configuring wireless networking software is greatly simplified, network adapters are Plug and Play so any late version of Windows recognizes one when installed into a PCI or PCie slot, or a USB port  Networks need a name which you will be prompted for during configuration Click on the Wireless select ICON Select Wireless network by Name

There are two different methods available with wireless ad hoc mode and infrastructure mode  Ad hoc mode, also called peer-to-peer mode, each node is in direct contact with each other node  Ad hoc­ mode networks are easier to configure than infrastructure-mode networks ◦ Suited for small groups of computers that need to transfer files or share printers ◦ Also good for temporary networks such as study groups or business meetings

There are two different methods available with wireless ad hoc mode and infrastructure mode  Infrastructure mode use one or more WAPs to connect  Designed for wireless network with many PCs, needs to have centralized con­trol over the wireless network  To connect wire­lessly to another network, such as the Internet, you need to use infrastructure mode

One of the major complaints about wireless networking is that it offers weak security  Often the only requirement to access a wireless network is walk into an unsecured WAP's coverage area and turn on your wireless device  Unsecured Data packets float through the air instead of traveling safely wrapped up inside network cabling  These packets can be intercepted

Wireless networks use multiple methods to secure access to the network itself and secure the data being transferred  Changing the default Service Set Identifier (SSID) parameter- also called the network name- and administrator password is the first step  The SSID is a 32-bit identifier for your WAP that is meant to be unique, but many WAPs ship with the same SSID and remain unchanged by unsuspecting users  Enabling wireless encryption - Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA), or WPA2 ensures that the data packets are secure in transit

The main security weaknesses in wireless networks is that out of the box, no security is configured  Wireless devices want to be heard, and by default WAPs are configured to broadcast their presence to their maximum range, welcoming all other wireless devices that respond  Always change the default SSID to something unique, and change the administrator password right away

How secure are default passwords?

Wired Equivalent Privacy (WEP) encryption was meant to secure data being wirelessly transmitted. WEP encryp­tion uses a standard 40-bit encryption to scramble data packets  Unfortunately WEP can be cracked in a matter of minutes using software readily available off the Internet  WEP is better than noth­ing, but only stops casual prying into a network

Wireless Protected Access (WPA) encryption addresses the weaknesses of WEP it functions as a security protocol upgrade to WEP-enabled devices  WPA offers security enhancements such as an encryption key integrity-checking feature and user authentication through the industry-standard Extensible Authentication Protocol (EAP)  The use of EAP is a huge security improvement over WEP. User names and passwords are encrypted and therefore much more secure

Recent versions of Mac OS-X and Microsoft Windows support WPA2 for securing wireless networks  WPA2 uses Advanced Encryption Standard (AES), among other improvements, to provide a secure wireless environment  WPA2 should be the security used on all Wireless systems

Wireless speeds depend on several factors mostly dependent upon the standard used by the wireless device  Another factor affecting speed is the distance between wireless nodes (or between wireless nodes and centralized WAPs). ◦ Devices dynamically negotiate top speed at which they can communicate without dropping too many data packets ◦ Speed decreases as distance increases, so the maximum throughput speed is achieved only at extremely close range (less than about 25 feet). ◦ At the outer reaches of a device's effec­tive range, speed may decrease to around 1 Mbps before it drops out altogether

Speed can also be affected by interference from other wireless devices operating in same frequency range  Cordless phones  Baby moni­tors  Microwave Ovens  Solid objects  Deadspots occur when something capable of blocking the radio signal comes between wireless network nodes  Electrical appli­ances are very effective at blocking wire­less network signals  Other culprits include electrical fuse boxes, metal plumbing, and air conditioning units

Range is greatly affected by outside factors, Interference from other wireless devices will affects range, as does interference from solid objects  Range can be increased in a couple of ways: ◦ Installing multiple WAPs to permit "roaming" between one WAP's coverage area and another ◦ Install a higher-gain antenna on some models that increases a single WAP's range ◦ Directional antennas can be used to dramatically increase range in specific directions

Standards for Wireless are based on the and Bluetooth Standards  The IEEE wireless Ethernet standard defines methods by which devices can com­municate using spread-spectrum radio waves  Spread-spectrum broadcasts data in small, discrete chunks over the different frequencies (channels) available within a certain frequency range  based wireless technologies broadcast and receive on one of two license­ free industrial, scientific, and medical (ISM) radio bands: 2.4 GHz and 5.8 GHz

Currently Wi-Fi is the most widely adopted type of wireless networking used by homes, public places, coffee shops, libraries…  Only wireless devices that conform to the extended versions of the standard a, b, g, and n- are Wi-Fi certified  Certification comes from the Wi-Fi Alliance, a nonprofit industry group made up of more than 175 member companies designing and manufacturing wireless networking products  Most wireless equipment will communicate with different devices, b will communicate with 802.g, the exception is a which operates on a different frequency

802.11a differs from all others in significant ways: a differs from all others in significant ways:  based standards operates on a different frequency range, 5GHz  This less-used frequency range means that a devices are less prone to interference from other devices  a also offers considerably greater throughput than b, reaching speeds up to 54 Mbps  Range is somewhat less about 150 feet  Despite the superior speed of a, it isn't widely adopted in the PC world

802.11b was the first widely accepted standard in wireless networking  b supports data throughput of up to 11Mbs and maxi­mum range of 300 feet  In a typical office environment, its maximum range is lower  Downside to b - it uses a very popular frequency 2.4 GHz band which is already crowded with baby monitors, garage openers, microwaves, and wireless phones, so you're likely to run into interference from other wireless devices

802.11g uses the best of both a and b creating a single standard  g offers transfer speeds equivalent to a, up to 54 Mbps, with the wider 300-foot range of b  More importantly, g runs in the 2.4 GHz band, so it is backward-compatible with b, meaning that the same g WAP can service both b and g wireless nodes  The g standard is popular, but losing ground to the newest version, n

802.11n standard brings improvements to Wi-Fi networking- faster speeds, new antenna technology  n specification requires all but handheld devices to use multiple antennae - a feature called multiple in/multiple out (MIMO), enabling the devices to make multiple simultaneous connections  With up to four antennae, n devices can achieve amazing speeds up to 600 Mbps  Like g, n WAPs run in the 2.4 GHz band, supporting earlier, slower b/g devices  The n standard also has a more powerful so-called dual-band capable of supporting a devices as well as b/g devices

Standard Max. speed a 54 Mbps b 11 Mbps g 54 Mbps n 100+ Mbps Max. range 150 feet 300 feet 300+ feet Frequency 5 GHz 24GHz 2.4 GHz 2.4 and 5 GHz Compatibility a802.11b802.11b,802.11g b,802.11g n (802.11a in some cases) Description Eight available channels. Less prone to interference than b and g. Fourteen channels available in the 2.4 GHz band (only 11 of which can be used in the U.S. due to FCC regulations). Improved security enhancements Fourteen channels available in the 2.4GHz band (only 11 of which can be used in the U.S. due to FCC regulations) Same as g but adds the 5 GHz band that a uses.