Part 1 1

WIRELESS NETWORK

SECURITY

Part 1 2

Understand basic wireless technology Understand the components of wireless

network and implement a wireless network

Build a wireless LAN Understand the security issues of

wireless network Look at various protection methods and

explore how to apply some of these protections to a school environment

Objective

Part 1 3

Brief introduction to networking WAN, MAN, LAN,

Fundamental Wireless Technologies Wireless LAN, Bluetooth Comparison of technologies and issues

Look at Wireless LAN component Wireless clients AP

Build different types of wireless networks Ad-hoc and infrastructure networks

Contents

Part 1 4

…..is a group of two or more personal computers or devices linked together with a media….

What is a Network?

Part 1 5

Typically connects computer in a single building or campus.

Medium : optical fibers, coaxial cables, twisted pair, wireless (WiFi).

High speed networks (100 Mbps/10 Gbps Ethernet)

Cheaper equipments, Ethernet, Token Ring

Setup Client and Server or Peer to Peer

Local Area Network (LAN)

Part 1 6

Generally covers large distances (states, countries, continents).

Typical Medium : Land and Ocean cables Wireless Medium - satallites. Problems with delays if using satellites. Typical speed : 20 - 2000 Kbits/s. -

expensive New standards (ATM) are changing the

landscape.

LAN vs WAN speed

Wide Area Network (WAN)

Part 1 7

Generally covers towns and cities (50 kms)

Typical medium : optical fibres, cables

Message routing is fast. Mobile technology – 2G, 3G and 4G

Metropolitan Area Network (MAN)

Part 1 8

Refers to Hardware and Software that allow information be transmitted between devices Devices

Equipment that can send and received Network

h/w & s/w used to link and transmit information over a media

Applications S/w that operate the wireless device

What is Wireless Technology?

Part 1 9

Mobility (Roaming) Easy of Installation Scalability (WiFi) Cost

Why Wireless

Part 1 10

Information access when needed, anywhere

Emergence of powerful handheld devices Improved network data exchange Maturing device, network and data

exchange standards

Why Wireless Now?

Part 1 11

To most people/organsiations wireless technology means:

Wireless technology refers to hardware and software that allows information to be transmitted between devices without using physical wired connections.

Wireless LAN GPRS

3GWiMax

Blue tooth

Some Wireless Technology?

Part 1 12

Home RF BlueTooth 802.11Max Trans. power 100mW 100mW 800mW

Data Rate 1-2 Mbps 1 Mbps Upto 300Mbps

Max device Up to 127 Up to 26 Up to 256

Security Blowfish 0, 40, and 60 bits 40, 128 RC4

TKIP, WPA

Range 150ft 30ft 400ft indoor

1500 OD

Cost Medium cheapest Most expensive

Roaming No No Yes

802.11 competes with HiperLAN

Wireless LAN Competing Technologies

Part 1 13

Operate in the gigahertz frequency spectrum but differ from other wireless technologies in the range of service, network capacity and data bit transfer rate.

Designed to operate over a much smaller service area.

Devices that participate in these types of peer based networks are designed to automatically discover other devices and services.

Connects personal computers to mobile devices including PDAs, phones, personal printers and other handheld devices.

Personal Area Network (PAN)

Part 1 14

Originated from an Ericsson internal project

To facilitate voice and data access Operate at 2.4 – 2.483 MHz ISM band Short range (10 meter) frequency-

hopping radio link between devices Data can be delivered up to 724 kbps

Bluetooth

Part 1 15

ClassMaximum Permitted Power(mW/dBm)

Range(approximate)

Class 1 100 mW (20 dBm) ~100 meters

Class 2 2.5 mW (4 dBm) ~10 meters

Class 3 1 mW (0 dBm) ~1 meter

1. Bluetooth 1.0 and 1.0B2. Bluetooth 1.1

1. Fixed problems with V1 and support for non encrypted channels3. Bluetooth 1.2

1. Better audio (Stereo sound, A2DP)4. Bluetooth 2.0

1. EDR (3Mbps)5. Bluetooth 2.1

1. Better power consumption2. Better Pairing

Bluetooth Standards (1)

Part 1 16

103 Hz

106 Hz

109 Hz

1012 Hz

1015 Hz

1018 Hz

1021 Hz

RadioUsed for

communication

MicrowaveUsed for heating, communication,

and radar

T-Ray

InfraredRemote control, optical network

Ultraviolet

X-RayPenetrating live tissues

Gamma RayEmitted by nuclear reaction

Radio Spectrum

Part 1 17

Mobile phones became popular in the 1980s and 1990s. Now in Hong Kong over 91% of the population owns a mobile phone. Various operators offer different services but they can be grouped into two types:

Mobile phones provide two major functions:Voice – GSM, CDMA, TDMA

Data - GRPS, WAP* SMS, EMS, MMS* Internet Access* Email* Value Added features

The most used wireless technology is the mobile phone

Mobile Phones Technology

Part 1 18

Cell using directional transceiver Cell using omnidirectional transceiver

Overlapping circular cellsIdealised hexagonal network

Microcell within network

Transmission and Cells

Part 1 19

1st Generation This the analog phones dominated by two main standards,

Analog Mobile Phone System (AMPS) and Total Access Communication System (TACS)

2nd Generation Digital phones with better sound quality CDMA, TDMA, GSM and PCS became common terms Basic data transmission, modem, fax at 9.6kbps

2.5 Generation Faster data transmission with GPRS, for SMS, MMS at 14.4k –

115kbps Enhanced Data for GSM Evolution (EDGE) allowed 384Kbps

3rd Generation WCDMA, CDMA2000 - Video streaming, high-speed Internet Development even faster data access at 2Mbps for Internet

applications

Since the development of mobile phones have seen a number of generations

Mobile Phone Development

Part 1 20

WIRELESS LAN TECHNOLOGIES

Part 1 21

The most popular WLAN technology today is based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11x standard.

IEEE 802.11

Frequency Range Throughput Data Rate Indoor dist.

802.11a 5 GHz 27 Mbps 6-54 Mbps ~ 35m

802.11b 2.4 GHz 5 Mbps 1-11 Mbps ~ 38m

802.11g 2.4 GHz 22 Mbps 6-54 Mbps ~ 100m

802.11n 5 and/or 2.4 Ghz Unknown 600 Mbps ~ 300m

plus error correction code

Draft 2(expect to rectify late 2009)

Wireless LAN Technology

Part 1 22

Proposed by IEEE 802.11 working group Started in May 1991 and completed in 1997 Transmission rate 1Mbps and 2Mbps 3 data transmission adopted

Frequency Hop Spread Spectrum (FHSS- 1Mbps) Direct Sequence Spread Spectrum (DSSS- 2Mbps) Infrared (IrDA – Infrared Data Association)

Original 802.11

Part 1 23

Added in Dec. 1999 Operating at 2.4GHz range Support speed 11, 5.5, 2 & 1Mbps Using Higher Rate - Direct-Sequence Spread

Spectrum (HR-DSSS) Employs the Complementary Code Keying

(CCK) modulation technique Newly added 22Mbps (802.11b+) Not official

802.11b

Part 1 24

Added in Dec. 1999 Operating at 5 GHz range Support speed 6, 9, 12, 18, 24, 36, 48 &

54Mbps Using Orthogonal Frequency Division

Multiplexing (OFDM)

802.11a

Part 1 25

• Added 2003 (Ratified in June)• Operating at 2.4 GHz range • Support speed between 24 and 54Mbps• Using Orthogonal Frequency Division

Multiplexing (OFDM) - Mandatory• Also support Complimentary Code Keying

(CCK) – Optional (backward compatibles with 802.11b)

802.11g

Part 1 26

IEEE 802.11 Specification

Part 1 27

BAND Frequency Range

UHF ISM 902 – 928 MHz

S-Band 2 – 4 GHz

S-Band ISM 2.4 – 2.5 GHz

C-Band 4 – 8 GHz

C-Band Satellite downlink 3.7 – 4.2 GHz

C-Band Radar (Whether) 5.25 – 5.925 GHz

C-Band ISM 5.725 -5.875 GHz

C-Band Satellite uplink 5.925 – 6.425 GHz

X-Band 8 – 12 GHz

X-band Radar (police) 8.25 – 10.55 GHz

Ku-Band 12 – 18 GHz

Ku-Band Radar (Police) 13.4 – 14 GHz

15.7 - 17.7 GHz

Allocated For Frequency Range

Mobile Phone 800 – 900 MHz

DECT 1.8 – 1.9 GHz

ISM 2.4 – 2.5 GHz

ISM (feasible) 5.725 -5.875 GHz

Fix Links (considering) 17, 18, 19 GHz

European Wireless LAN

(Await standards)

24.1 GHz

USA Allocation Hong Kong Allocation

ISM = Industrial, Scientific and Medical

Radio Frequency for Wireless LAN

Part 1 28

Hong Kong Allocation for

802.11b

Part 1 29

Hong Kong Allocation for

802.11a

Part 1 30

Channel Frequency Channel Frequency

1 2.412Ghz 8 2.447Ghz

2 2.417Ghz 9 2.452Ghz

3 2.422Ghz 10 2.457Ghz

4 2.427Ghz 11 2.462Ghz

5 2.432Ghz 12 2.467Ghz

6 2.437Ghz 13 2.472Ghz

7 2.442Ghz 14 2.484Ghz

Wireless 802.11b networks operate in UHF band, specifically between 2.4GHz and 2.5GHz. These Wireless 802.11b networks operate in UHF band, specifically between 2.4GHz and 2.5GHz. These frequency is divided into 14 channelsfrequency is divided into 14 channels..US & Canada channel 1- 11 is available, Europe use 1 – 13, France uses 10-13 and Japan 1-14.US & Canada channel 1- 11 is available, Europe use 1 – 13, France uses 10-13 and Japan 1-14.

802.11b Channels

Part 1 31

CH1 CH2 CH3 CH4 CH5

CH1 CH2 CH3 CH4 CH5 CH6

CH1 CH2 CH3 CH4 CH5 CH6 CH7

CH1 CH2 CH3 CH4 CH5 CH6 CH7 CH8

CH1 CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9

CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10 CH11

CH4 CH5 CH6 CH7 CH8 CH9 CH10 CH11

CH5 CH6 CH7 CH8 CH9 CH10 CH11

CH6 CH7 CH8 CH9 CH10 CH11

CH7 CH8 CH9 CH10 CH11

Data is not transmitted in a single frequency, it is spread over multiple frequenciesData is not transmitted in a single frequency, it is spread over multiple frequencies

From the rule set only channel 1 , 6 and 11 do not overlap. From the rule set only channel 1 , 6 and 11 do not overlap. But channel 5, 6 , and 7 affects all rule sets (Ideal for Jammers)But channel 5, 6 , and 7 affects all rule sets (Ideal for Jammers)

Channel used for sending data

Part 1 32

Each DS (Direct Sequence) Channel is transmitted over 22 Mhz Each DS (Direct Sequence) Channel is transmitted over 22 Mhz Channel Centers are separated by 5 MhzChannel Centers are separated by 5 Mhz

Channel Allocations for 802.11b

Part 1 33

20 Mhz 20 Mhz

5150 5180 5200 5220 5240 5260 5280 5300 5320 5350

Each channel is 20MhzEach channel is 20Mhz

Channel Allocations for 802.11a

Part 1 34

Wire LAN

1. Connect to AP2. Configure to AP3. Test connection to Internet

Wireless LAN setup Demo

Part 1 35

Speed Out Doors In Doors

11Mbps 150m (500ft) 30m (100ft)

5.5Mbps 270m (880ft) 50m (160ft)

2Mbps 400m (1300ft) 70m (220ft)

1Mbps 460m (1500ft) 90m (280ft)

Speed vs Distance (2.4 Ghz)

Part 1 36

Speed Out Doors In Doors

72 Mbps 40m (133ft) 20m (66ft)

54 Mbps 80m (262ft) 25m (82ft)

48 Mbps 230m (755ft) 35m (115ft)

36 Mbps 300m (984ft) 40m (131ft)

24 Mbps 340m (1115ft) 45m (148ft)

18 Mbps 370m (1214ft) 50m (164ft)

12 Mbps 400m (1312ft) 55m (180ft)

9 Mbps 465m (1526ft) 57ft (187ft)

6 Mbps 500m (1650ft) 60m (197ft)

802.11a+ ?802.11a+ ?

Speed vs Distance (5 Ghz)

Part 1 37

RF Barrier Relative Degree of Attenuation Example:Air Minimal

Wood Low Office partitions

Plaster Low Inner walls

Synthetic material

Low Office partitions

Asbestos Low Ceiling

Glass Low Windows

Water Medium Damp wood, aquariums

Brick Medium Inner and outer wall

Marble Medium Inner wall

Paper High Paper rolls, cardboard boxes

Concrete High Floor and outer walls

Bullet-proff glass High Security booth

Metal Very High Desks, office partitions, elevator shafts, reinforced walls

What affects Range of Transmission

Part 1 38

Newest Wireless LAN standard Final retification expected to be at late 2009

• Currently is Draft version 2• Backward compatible to 802.11a/b/g

Release Date

Op. FrequencyData Rate (Typ)

Data Rate (Max)

Range (Indoor)

Mid 20085 GHz and/or 2.4 GHz

150 Mbit/s300Mbit/s (2 stream)

~70 meters

802.11n

Part 1 39

MIMO (Multiple Input - Multiple Output) defines many "M x N" antenna configurations, ranging from "1

x 1" to "4 x 4". This refers to the number of transmit (M) and receive (N) antennas – for example, an AP with two transmit and three receive antennas is a "2 x 3" MIMO device.

Better dealing with multipath signal reflections and attenuation

Channel Bonding bonding to combine two adjacent 20 MHz channels into a single

40 MHz channel (most effective at 5GHz) increases that throughput to 150 Mbps per channel

Aggregating of Frame Transmit more than one application in single frame with fix

header

802.11n New Feature

Part 1 40

Wireless LAN

Components

Part 1 41

Wireless client a computing device that is equipped with a wireless LAN network adapter. Wireless clients can communicate directly with each other or through a wireless access point.

Wireless Access Pointa networking device equipped with a wireless LAN network adapter that acts as a bridge between wireless client and a traditional wired network

Wireless LAN Components

Part 1 42

PCMCIAPCMCIA

USBUSB

Internal Internal PCMCIA PCMCIA AdapterAdapter Internal Wireless Internal Wireless

InterfaceInterface

Various Wireless Adapters for client

Part 1 43

The basic building block of an 802.11 network is the Basic Service set (BSS), which is simply a group of stations that communicate with each other

Ad-hoc BSS Infrastructure BSS

Basic Service Set

Part 1 44

Extended Service Set is for large networks

Internet

Extended BSS

AP (Bridge mode setting)

Extended Service Set

Part 1 45

Wire LAN

1. Ist client create a SSID(making it visible) and create a share folder with a file for other clients to download

2. Other Clients join this network3. Test connection by download a file from 1st client

Workshop – Build simple wireless LAN (Ad-Hoc)

Part 1 46

Need wireless network adapter Define an SSID (Service Set

IDentification) for “Adhoc” network All client connects to this SSID

Install driver of Wireless Network AdapterClient 1 – set up a wireless group with SSID ADHOCxx – xx = 01 – 10Client 2 – Connect to the ad-hoc network

Building A Simple wireless network

Part 1 47

At least 2 interface Wireless Interface (802.11x) Wired Interface (Ethernet or WAN port)

Bridge table Dynamic Host Configuration Protocol

(DHCP) Network Address Translation (NAT) Security filtering and Monitoring

Access Point is a mean connecting wireless world and the wired world

Some feature provided by APSome feature provided by AP

What is an Access Point?

Part 1 48

Target at price-conscious users Simple connectivity Limited functions

1 - Residential Gateways/Routers1 - Residential Gateways/Routers

2 – Enterprise Gateways (AP)2 – Enterprise Gateways (AP)

• More expensive• Large network connectivity and multi APs• More sophisticated functions

– Device management– Greater Security functions

2 types of APs

Part 1 49

Suitable for home or small office use Deploy with one routable IP address, so

NAT is implemented Aim for connecting to a WAN via modem May support VPN pass-through

IPSec PPTP

Example:Linksys WRT610NSMC WGBR14S-NDlink DIR655

Residential Gateways / Routers

Part 1 50

Wireless NIC

Internet

ADSL/Cable Modem

Wireless Router

Internal Addresses

Perform NATInternal Real IP address

Home / small office setup

Part 1 51

Various different names but often just call AP Provide a bridging function between wireless

devices and wired network Provide Inter-Access Point Protocol (IAPP - 802.11F) Roaming Upgrade path, from 802.11b, to 802.11a to

802.11g and to 802.11n Provide SNMP management tools included Provide external antenna facilities VPN, VLAN functions

Example:Example:Orinoco AP2000Orinoco AP2000Cisco Aironet 1220Cisco Aironet 12203COM AirConnect3COM AirConnect

Enterprise Gateways

Part 1 52

Sales Dept.HR. Dept

Wired Network

SwitchInternet

Router

Wireless PCMCIA

Bridge the wireless to Wired

Network address same as wired segment

Enterprise AP

Part 1 53

Should be Wi-Fi (Wireless Fidelity) Number of ports (including printer?) Device Management facility - Web based? More than one AP? Roaming required? Security functions Price Transmission power

Selecting Access Point

Part 1 54

1. Access the AP with browser or vendor supplied software, either wireless or directly connected. Use factory URL (192.168.1.1)

2. Login with factory user ID and password (1234)3. Use Web configurator to set up SSID for Open Access (no security)4. Create a share folder with some files for sharing

Workshop – Build Enterprise wireless LAN (Router Mode)

Part 1 55

Disable all wired Network adapters Insert USB wireless Client (install driver) Use Windows XP’s Zero Configuration Utility

and scan for available wireless network Locate your group’s SSID and Connect to

your group’s network Use the command IPCONFIG at cmd prompt

to identify what IP address was assigned to your system

Use IE to access an external site. Were u successful?

Workshop – Build Enterprise wireless LAN (client setup)

Part 1 56

1. Access the AP with browser or vendor supplied software, either wireless or directly connected. Use factory URL (192.168.1.1)

2. Login with factory user ID and password (1234)3. Configure the Access Point to run as AP mode (bridge mode)

Workshop – Build Enterprise wireless LAN (AP Mode)

Part 1 57

Use Windows XP’s Zero Configuration Utility and scan for available wireless network

Locate your group’s SSID and Connect to your group’s network

Use the command IPCONFIG at Command prompt to identify what IP address was assigned to your system. Any different to the previous exercise?

Use IE to access an external site. Were you successful?

Workshop – Build Enterprise wireless LAN (client setup)

Part 1 58

ANTENNAS

Part 1 59

Gain is a measure of increase in power.

GAIN

DirectionDirection is the shape of the transmission pattern.

An antenna rating is typically to the gain of an isotropic or dipole antenna. An isotropic antenna is a theoretical antenna with a uniform three-dimensional radiation pattern (similar to a light bulb with no reflector). dBi is used to compare the power level of a given antenna to the theoretical isotropic antenna.An isotropic antenna is said to have a power rating of 0 dB; for example, zero gain/loss when compared to itself.

Some antennas are rated in comparison to dipole antennas. This is denoted by the suffix dBd. Dipole have a stronger gain of 2.14 db when compare with isotropic antenna. Hence, dipole antennas have a gain of 0 dBd (= 2.14 dBi).

An antenna gives the wireless system two fundamental properties

Antenna Properties

Part 1 60

Omni-Directional Directional

360 degree Radiation pattern The Standard increased power of 2.4dbi (“Rubber Duck”)

Normally no increase of power Redirect s the energy Angle of radiation is decreasedGreater distance is covered

Directional Antennas

Part 1 61

Antenna Examples

Part 1 62

increase Factor Decrease Factor

0 dB 1x 0 dB 1x

1 dB 1.25 x -1 dB 0.8x

3 dB 2x -3 dB 0.5x

6 dB 4x -6 dB 0.25x

10 dB 10x -10 dB 0.1x

12 dB 16x -12 dB 0.06x

20 dB 100x -20 dB 0.01x

30 dB 1000x -30 dB 0.001x

40 dB 10,000x -40 dB 0.0001x

dB = 10 log10 (Power A/Power B)

When replacing antenna, this can be used for reference

Antenna Power factor

Part 1 63

Good reception Gain maximum speed and distance Reduce interference Security

Why Select Correct Antenna?

Part 1 64

Review the wireless needs of your school Prepare a network diagram , if needed (simple

PowerPoint) Consider any security issues that may exist or may

have

For discussion at next session

Assignment

Part 1 65

APPENDIX

Part 1 66

Power LED Switch LED WAN LEDGreen – 100MbpsOrange – 1000MbpsBlink – data Tx/Rx

Wireless LEDBlink – data Tx/Rx

Encryption ON/OFF

Reset switch at back of device

Workshop AP introduction

Part 1 67

Changing Router mode to AP mode

Workshop AP introduction

Part 1 68

All AP (not in router mode) must be on same subnet and configured with same ESSID

Adjacent AP must use a different channel when coverage area overlapped

All APs must use same port number to relay roaming information

APs must be connected to the wired network and uses DHCP server to assign dynamic IP address

If 802.1x is used for user authentication, it is recommended to use server. If authentication is performed locally at the AP, then all APs must have user’s profile

Roaming Requirements