20 - Wireless Networking

8/14/2019 20 - Wireless Networking

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Introduction to Wir eles sThe term wireless is normally used to refer to any type of electrical or electronic operationwhich is accomplished without the use of a "hard wired" connection.

For a long range communications, it is impossible or impractical to implement with the useof wires.

Radio transmitters and receivers, computer networks, network terminals which use someform of energy (e.g.,radio frequency (RF), infrared light, laser light, visible light, or acousticenergy) to transfer information without the use of wires. Information is transferred in thismanner over both short and long distances.

Wireless technology is based on the IEEE (Institute of Electronics andElectrical Engineers) 802.11 standard, which is one of the manystandards of the IEEE 802 LAN/WAN standards 802.11 used to becurrently the most affordable and available specification, but astechnology keeps on evolving, now the most affordable standard is

802.11g. The most important factor here is the bandwidth provided bythe standard. When wireless network was first introduced the 802.11standard could only provide 1 – 2 Mbps connection speed. Later, the802.11b provided 11 Mbps bandwidth. Both 802.11a and 802.11gstandards provide 54 Mbps connection speed between the wirelessdevice and the access point

http://en.wikipedia.org/wiki/Electrical


http://en.wikipedia.org/wiki/Electronic

http://en.wikipedia.org/wiki/Electronic




Introduction

Wireless networks are growing in popularityInstead of CAT5 or CAT 6 network cables, wireless

networks use radio waves to communicate witheach other.Most of today’s wireless networks arebased on the IEEE 802.11 standard.



WIRELESS PRODUCTSWIRELESS PRODUCTSRouter s & GatewaysRouter s & Gateways

Switch esSwitch es

Power Over Ethernet Adap tersPower Over Ethernet Adap tersWireless Access PointsWireless Access PointsWireless Print ServersWireless Print ServersWireless AntennasWireless Antennas

Wireless Storage DevicesWireless Storage DevicesStorage Ce ntralStorage Ce ntralWireless G ame BoxWireless G ame Box

X Box

http://netgear.com/Products/Switches/UnmanagedSwitches.aspx






http://netgear.com/Products/Storage/NetworkStorage.aspx






http://netgear.com/Products/RoutersandGateways/AGDualBandWirelessRouters.aspx



WiFiWiFi

WiMAXWiMAX WLANWLAN

WIRELESS TECHNOLOGY INNETWORKING

http://library.thinkquest.org/04oct/01721/wireless/wifimain.htm


http://library.thinkquest.org/04oct/01721/wireless/wimax.htm


http://library.thinkquest.org/04oct/01721/wireless/wlanmain.htm







WiFiWiFi

WiFiWiFi is the wireless way to handle networking.is the wireless way to handle networking.It is also known asIt is also known as 802.11 networking802.11 networking andand

wireless networkingwireless networking .. The big advantage of WiFi is its simplicity. You can The big advantage of WiFi is its simplicity. You canconnect computers anywhere in your home orconnect computers anywhere in your home oroffice without the need for wires.office without the need for wires.

The computers connect to the network using radio The computers connect to the network using radio

signals, and computers can be up to 100 feet or sosignals, and computers can be up to 100 feet or soapart.apart.



WI-MAX

WiMAX (Worldwide Interoperability for Microwave Access) is the IEEE802.16standards-based wireless technology that provides MAN(Metropolitan Area Network)broadband connectivity. WiMAX is an Air Interface for FixedBroadband Wireless Access Systems, also known as the IEEE WirelessMAN air interface.



WLANWLAN

Most industry estimates suggest that more than 85% of allenterprises will have at least one WLAN installation by 2007. The Wi-Fi Alliance believes it is critical For IT managers to

understand the risks of WLANs and immediately takeprudent action to secure their installation.WLAN Security Breaches There are two aspects of WLAN security: data protection (encryption)and network access control (authentication). Breaches can occur at thenetwork level via the wireless access point (AP), or at an individual PC -

either attached to a network or operating in ad hoc mode and

communicating in a peer-to-peer fashion. The result of a wirelessprivacy breach is the same as it would be for a physical wire basednetwork privacy issue: corporate data is at risk for third party recoveryor modification. Because of the broadcast nature of wireless, however,

providing data protection is much more challenging with wirelessnetworks. Network breaches range from someone taking unauthorized

enterprise network bandwidth to connect to the Internet, to attempts ataccessin cor orate secrets.



WIRELESS SECURITY WIRELESS SECURITY Wireless Encryption - WEP, WPA, and WPA2.Wireless Encryption - WEP, WPA, and WPA2.

This a very basic description of the differences between Encryption Security Methods used This a very basic description of the differences between Encryption Security Methods usedby Entry Level Wireless Hardware (802.11b/g).by Entry Level Wireless Hardware (802.11b/g).

WEP.WEP.Each packet of the Encryption has 24bits Initialization vector. Which unfortunately done inEach packet of the Encryption has 24bits Initialization vector. Which unfortunately done inplaintext.plaintext.

40bits (encryption)+ 24bits(init. vector)=64bits Encryption.40bits (encryption)+ 24bits(init. vector)=64bits Encryption.

104bit(encryption)+ 24bits(init. vector)=128bits Encryption.104bit(encryption)+ 24bits(init. vector)=128bits Encryption.

WEP uses RC4 stream encryption, for a fresh key stream for each packet.WEP uses RC4 stream encryption, for a fresh key stream for each packet.

The Init Vector & the key are combined to get per-packet key which is used to generate The Init Vector & the key are combined to get per-packet key which is used to generateRC4 keys stream.RC4 keys stream.

The RC4 is one of the major culprits in the security issues. The RC4 is one of the major culprits in the security issues.

Part of the weakness of RC4 has to do with the combo of Init. Vector and Plain TextPart of the weakness of RC4 has to do with the combo of Init. Vector and Plain Textchipper.chipper.

24 bit Init vector is finishing a cycle of 2 in the power of 24 in about hour and then repeats.24 bit Init vector is finishing a cycle of 2 in the power of 24 in about hour and then repeats.

Repeating Init Vector plus knowledge about the plaintext language, makes guessing theRepeating Init Vector plus knowledge about the plaintext language, makes guessing theplaintexts simpler.plaintexts simpler.



WPAWPAWPAWPAIt is an interim solution that is used now until 802.11i comes out.It is an interim solution that is used now until 802.11i comes out.

It still using RC4, but the Key was changed to TKIP.It still using RC4, but the Key was changed to TKIP.

TKIP basically works by generating a sequence of WEP keys based on a master TKIP basically works by generating a sequence of WEP keys based on a masterkey, and re-keying periodically before enough volume of info. could be capturedkey, and re-keying periodically before enough volume of info. could be capturedto allow recovery of the WEP key. TKIP changes the Key every 10,000 packets,to allow recovery of the WEP key. TKIP changes the Key every 10,000 packets,which is quick enough to combat statistical methods to analyze the cipher.which is quick enough to combat statistical methods to analyze the cipher.

TKIP also adds into the picture the Message Integrity Code (MIC). The TKIP also adds into the picture the Message Integrity Code (MIC). Thetransmission’s CRC, and ICV (Integrity Check Value) is checked. If the packettransmission’s CRC, and ICV (Integrity Check Value) is checked. If the packetwas tampered with. WPA will stop using the current keys and re-keys.was tampered with. WPA will stop using the current keys and re-keys.The Big Change will be Advance Encryption Standard (AES).The Big Change will be Advance Encryption Standard (AES).

802.11i will change the WPA RC4 usage to employ AES.802.11i will change the WPA RC4 usage to employ AES.Referred to as WPA2 the main difference for regular user would be.Referred to as WPA2 the main difference for regular user would be.WPA uses (as describe above) TKIP/MIC Encryption.WPA uses (as describe above) TKIP/MIC Encryption.WPA2 uses AES-CCMP EncryptionWPA2 uses AES-CCMP Encryption

AES aka the Rijndael algorithm is a secure, fast symmetric cipher that is easilyAES aka the Rijndael algorithm is a secure, fast symmetric cipher that is easilyimplemented in hardware.implemented in hardware.

AES has its own mechanism for dynamic key generation. It's also resistant toAES has its own mechanism for dynamic key generation. It's also resistant tostatistical analysis of the cipher text.statistical analysis of the cipher text.Counter-Mode/CBC-MAC Protocol (CCMP) called the Advanced EncryptionCounter-Mode/CBC-MAC Protocol (CCMP) called the Advanced EncryptionStandard (AES).Standard (AES).



Ease to installEase to installEase to modifyEase to modifyMobilityMobility

PortabilityPortabilityInter-connectabilityInter-connectabilityExpandabilityExpandabilityEase to be segmentedEase to be segmented

Being economicalBeing economicalTransparencyTransparencyReusabilityReusabilityHaving broad range of coverage and optionsHaving broad range of coverage and options

Advantages of Wireless

Technology



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20 - Wireless Networking

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