Wireless Networking Chapter 12

Chapter Objectives Identify wireless networking Compare wireless and wired network Explain the different wireless standards List the components required for wireless networking Discuss the various applications of wireless networking Troubleshoot wireless network problems Release 16/7/2009

Recall Structured Cabling is a set of standards that determine how to create a central point to start the wiring for data or voice communications The subsystems of structured cabling systems:  Entrance Facilities  Equipment Room  Telecommunications Room  Backbone Cabling  Horizontal Cabling  Administration and Work Area Conduits are plastic pipes that run through wall plate to wiring closet and between the wiring closets Release 16/7/2009

Wireless Networking Basics Wireless networking allows you to establish:  Communication using standard network protocols and use radio frequency  Communication without the use of cables  Technologies used for wireless access based on Wireless fidelity (Wi-Fi) Home Radio Frequency (HomeRF) Release 16/7/2009

Types of wireless network from CBT Release 16/7/2009

Types of Wireless Network – I Peer-to-Peer(P2P) or Ad-Hoc  Connected wirelessly with the use of wireless Network Interface Card (NIC)  Computers can access printers and share files  Wired LAN can be accessed using bridging Release 16/7/2009

Types of Wireless Network – II Access point or Infrastructure wireless LAN  Wireless device connects to the access point to connect to the network  Access point acts as a hub to connect two wireless devices  Wireless bridge used to connect wireless network to wired network Release 16/7/2009

Wireless Standards Variety of standards accepted worldwide and offer different levels of security Wireless Standards IEEE BluetoothIrDAHomeRFWiMAX Release 16/7/2009

IEEE – I Developed by Institute of Electrical and Electronic Engineers (IEEE) for defining different aspects of Radio Frequency Wireless networking IEEE Standards a802.11b802.11g802.11n Release 16/7/2009

IEEE – II StandardData Rate Max range FrequencyCompatibility Mbps46 meter 2.4 GHz a54Mbps46 meter 5 GHz802.11a b11Mbps91 meter 2.4 GHz802.11b g54Mbps91 meter 2.4 GHz802.11b, g n540 Mbps 2.4/5 GHz Release 16/7/2009

IEEE – III Security  Four methods of wireless network security: Data encryption (WEP and WPA) Port based access control Service Set Identifier (SSID) Media Access Control (MAC) address filtering Release 16/7/2009

Security - I WEP – suitable for small network  Uses 64/128 encryption algorithm  Encryption key is static and shared  No mechanism for user authentication WPA – uses dynamic encryption key user authentication through Extensible Authentication Protocol (EAP) SSID – is a 32 character unique identifier inserted into header of each packet to secure your network configure your AP with unique SSID name Release 16/7/2009

Security - II MAC address filtering – preferred for smaller network  MAC address listed in the list can access other devices in the network  If any NIC is failed then you have to reconfigure the AP Port Based Access control (802.1x) – uses EAP hardware used such as supplicant, authenticator, and authenticating server must be 802.1x enabled to use the network Release 16/7/2009

Components Requirements The important components required for setting up a wireless network are:  Medium  Access point and Extension point  Wireless bridges and Power line bridges  Antennas  Wireless adapters  Wireless Station and Server  Software Release 16/7/2009

Medium Wireless medium is an unguided form of networking medium Wireless transmission involves use of technologies such as Bluetooth, Infrared, Lasers, Radio signals and Microwave technologies Lasers, infrared and Bluetooth are used mainly in LAN environment whereas microwave and other radio frequencies are used to connect vast geographical locations Mobile computing allows users to do their work at any location Release 16/7/2009

Access Point and Extension Point Access Point  Device that bridges a wireless connection and a wired connection  Two types of access points: Hardware access points and Software access points  Generally acts as a hub and operates at layer 1 Extension Point  Used if single access point is not able to cover entire area  Acts as wireless relay extending the range of wireless network Release 16/7/2009

Hardware Access Points Hardware access point is a physical device that is used to establish a connection between a wired network and a wireless network Release 16/7/2009

Software Access Points Software Access Points are computer which includes a wireless network interface card. Release 16/7/2009

Extension Point Extension points are used if a single access point is not able to cover the entire area. Release 16/7/2009

Wireless and Power-line bridges Wireless bridge  Used to connect two or more wireless networks Power-line bridge  Used to penetrate a wireless network that is otherwise difficult to penetrate Release 16/7/2009

Antennas and Adapters Antennas are used to increase the range of wireless network Antennas should be compatible with the router, AP or the adapter i.e. installed in the network Types of antennas used:  Omnidirectional antennas - Used indoors and small in size  Directional antennas - High gain and used for long range outdoor use Wireless adapters help to connect computer or PDA to a network Wireless adapters are available as PC cards, PCI and mini PCI, USB, and CompactFlash. Release 16/7/2009

Wireless Station and Server Wireless Local Area Network consists of wireless station and wireless server Wireless station - Connects wireless network into a wireless medium Wireless Stations Wireless Clients Access Points Wireless server – The main server connected to the wired network which controls all devices within the wireless network Release 16/7/2009

Software Wireless network adapter requires two types of software so as to function properly:  Driver  Configuration Utility Windows XP has built-in tools for configuring network adapter settings It is better to use the drivers and configuration utilities provided by the vendor along with the wireless adapter Release 16/7/2009

Case Study 1 Hyderabad branch of MoneyMaker bank has a wireless network setup in the whole office. Network administrator Smith identifies that the signal strength in the insurance department is slightly weak as compared to other parts of the office. It provides poor connectivity to the wireless devices present in that department. Release 16/7/2009

Problem Signal strength is slightly weak Release 16/7/2009

Suggested Solution Access point is away from the insurance department. Smith can connect an extension point to the existing access point to increase the range of the wireless network. If the problem still exists then add an access point. Release 16/7/2009

Application Common applications of wireless technologies:  Wireless Local Area Network (WLAN)  Wireless Wide Area Network (WWAN)  Wireless Personal Area Network (WPAN)  Wireless Metropolitan Area Network (WMAN)  Mobile Computing Release 16/7/2009

Show troubleshooting from the CBT Release 16/7/2009

Troubleshooting – I Wire and Wireless Adapter  Software Troubleshooting - Wireless adapter configuration utility and wireless AP’s firmware version Driver Compatibility Low signal strength – Can be solved with:  Interference  Installing repeater  Changing Antenna  Installing Window XP Service Pack 2 Release 16/7/2009

Troubleshooting – II Network settings – Common network setting problems are:  SSID setting  DHCP Addresses  Encryption Keys  MAC Address Filters Release 16/7/2009

Case Study 2 The MoneyMaker bank’s Hyderabad branch office has setup a wireless network. The network engineer Smith receives complains about slow connectivity from an employee whose computer is located slightly far away from the access point. Release 16/7/2009

Problem Low signal strength Release 16/7/2009

Suggested Solution Smith should try placing the access point at a central location far away from physical obstructions and mirrors. He can also change the position of the antenna sideways or downwards just to check if there is better reception. He can also replace the antenna with a high gain antenna or install a repeater to troubleshoot the problem if there is no success in the previous solution. Release 16/7/2009

Summary – I Peer-to-peer and ad-hoc access point wireless LAN are types of wireless networks is a standard which was developed by Institute of Electrical and Electronic Engineers (IEEE) for defining all aspects of Radio Frequency Wireless networking IEEE , IEEE a, IEEE b, IEEE g and IEEE n are the different IEEE standards Methods of wireless network security are Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA), Service Set Identifier (SSID), Media Access Control (MAC) address filtering and Port Based Access Control: 802.1x Release 16/7/2009

Summary – II Bluetooth is a radio standard and communication protocol with low power consumption and short range of transmission and reception Bluetooth 1.0 and 1.0B, Bluetooth 1.1, Bluetooth 1.2, and Bluetooth 2.0 are the different Bluetooth standards Bluetooth devices operate in a master/slave scheme where in the master device can controls up to seven active slave devices The Bluetooth devices go through four different stages before starting a communication: device discovery, name discovery, association and service discovery The various services that are supported by Bluetooth are known as profiles and there are 13 Bluetooth services Release 16/7/2009

Summary – III IrDA is the example of free space optical communication over a short range IrPHY, IrLAP, IrLMP, Tiny TP, IrCOMM, IrOBEX, and IrLAN are the different layers of IrDA specifications In Infrared the two devices must be configured in an ad-hoc mode thereby making it more vulnerable to interference Infrastructure mode is not available in infrared communication Security features like encryption and decryption are not available in IrDA Microwave and Radio Frequency (RF) are the medium for wireless networking Release 16/7/2009

Summary – IV Hardware access points and Software access points are the two types of access points Wireless bridge is used to connect two or more wireless or wired networks Antennas are used to increase the range of the wireless network Wireless adapter card helps to connect the computer or a laptop to a wireless network Devices that can connect to the wireless network through a wireless medium are known as Wireless stations Wireless server is the main server that is connected to the wired network Release 16/7/2009