1. Remote Access for Mobile Computing Andrew Jessett NT Support and Development Group (a.k.a. PC Support) www.pcsupport.rl.ac.uk Business and Information Technology Department

2. The Dial-up Servers

3. RAL RAS Service - VPN Virtual Private Network PPTP - Point to Point Tunnelling Protocol Allows secure connection from any* Internet connection

4. Point to Point Tunneling Protocol Provides a secure tunnel between client and corporate LAN creating what is termed a V irtual P rivate N etwork

5. RAL RAS Service Authentication is by CLRC NT domain not RAS User account must have dial-up permission set Each server issues IP addressess from pool Though user can have fixed address if required

6. RAL RAS Service Connection problems Usually bad line Local loop fault House wiring - REN DACS -line sharing device limits speed Modem incompatibility WinModems and low cost modems Modem configuration files (drivers) Rarely server problem :-)

7. Global Roaming (GRIC) Allows connection to local ISP wherever user is visiting Local call charge to user + per minute charge to account Allows access to mail at RAL Used with PPTP allows access to the RAL Intranet

8. Other connection methods I ntegrated S ervices D igital N etwork (BT Home Highway) A symmetric D igital S ubscriber L ine Cable modems Wireless networking

9. Wireless Networking Wireless Ethernet Bluetooth Mobile phone - GSM, GPRS, UMTS

10. Wireless Ethernet Two or more wireless-enabled devices create own wireless network without an AP Using an Access Point Wireless clients connect to the LAN

11. Wireless Ethernet IEEE 802.11b11Mbps2.45 Ghz (ISM) IEEE 802.11g54 Mbps2.45 Ghz (ISM) IEEE 802.11a 54 Mbps5 Ghz (IEEE 802.11h 54 Mbps5 Ghz) HiperLan254 Mbps5 Ghz

12. Wireless Ethernet Security Service Set Identifier (SSID) Associated with AP or AP group. Can be used to segment wireless network Media Access Control (MAC) address filtering Access allowed/denied by physical address Wired Equivalent Privacy (WEP) Encryption and authentication via common key Very weak - even WEP can be cracked Latest hacker sport - “War Driving”

13. Bluetooth Alternative to IR port Wireless connection of all peripherals Connection to LAN Uses 2.45 Ghz ISM band 721 kbps Up to 8 active devices in Piconet Interconnect Piconets to form Scatter Nets

14. Mobile phone With external GSM modem allows connections typically 9.6 kbps, possible 14.4 kbps depending on service provider More recent WAP enabled phones have internal modem WAP - Wireless Access Protocol Circuit-switched therefore cost depends on duration of call GSM - Global System for Mobile

15. Mobile phone Works on top of GSM but is connectionless. Therefore costs are base on the amount of data passed Data rates of 56 - 114 kbps plus Generation 2.5 therefore stopgap until 3G GPRS - General Packet Radio Service

16. Mobile phone Third generation - 3G Completely separate system requiring new infrastructure Data rates of 2 Mbps plus Connectionless UMTS - Universal Telecommunications System