1. Chapter 10 Remote Access and Wireless Networking Business Issues Logical & Physical Topology Technology: Hardware & Software, & Wireless Personnel Communication Services

2. Business Issues Needs Costs Functions

3. Business Needs Telecommuting or Small Office Home Office (SOHO) Mobile computing for field representatives Remote technical support for customers

4. Hidden Costs Communication carriers service costs Wiring & bandwidth Management problems

5. Functions Exchange e-mail Upload & download files Remote access application programs Share LAN-attached resources

6. Logical Topology Remote node or remote access –Full client/server application –Use remote hard drive Remote control –Keystrokes and screen image –Input or output device for local PC –Use local PC hard drive

7. Security Consideration Password and its management Intrusion response Partitioning of data Encryption Dial-back systems Authentication protocol

8. Token Authentication- Types Types –Token response Private identification number (client) Challenge number (server) Challenge response number (client) –Time-synchronous authentication Private identification number (client) Random authentication number (client) Random authentication number (server)

9. Token Authentication - Management Encrypt data, ID, & password between client and server Auditable for failed attempts Limited remote access (time & day) Interoperate authentication server & communication server

10. Physical Topology Wire or wireless Serial port of a LAN-attached PC Communication server LAN modem (dial-in server) with four to eight PC Card (PCMCIA) slots

11. Hardware Communication servers –Offer application –Serial ports, CPU(s), & network interface card(s) Remote node servers (gateway) –Offer remote node connection service –Application servers offer application –Compatibility, LAN & WAN services, call management issue

12. Software Types Remote node software Remote control software Mobile-aware OS Mobile-aware application Mobile middleware

13. Remote Node Software Consideration: –Protocols, modem, & client support –Management –Security Types: Windows NT RAS & NetWare Connect PPP clients work with different server NOS

14. Remote Control Software Guest (remote) & host (local) Consideration –Compatibility (protocol, LAN) –Applications (file transfer etc.) –Security (virus etc.) –Avoid lock of host PC

15. Mobile-aware OS Functions Auto-detection of multiple configurations Built-in multiprotocol remote node client Direct cable connection File transfer and file/directory synchronization Deferred printing Power management Infrared connection

16. Mobile-aware Applications Oracle Mobile Agents (Oracle-in-Motion) 50:1 performance increase Client/agent/server architecture –Message manager (client): tracking pending requests on various servers through LAN links or PPP-based dial- up links –Message gateway(server): message holding station between message manager and intelligent agent on server to minimize overhead –Agent event manager (intelligent agent on server): represents mobile client during entire processing on server to save bandwidth and transmission time

17. Mobile Middleware Function: consolidate multiple client application request into a single transmission Pros: –Flexibility –Performance

18. Improve Remote Software Performance V.34 modems ISDN services 16550 UARTs and matching serial port drivers Data compression software/hardware Communication software Compatibility

19. Mobile MIB Balance between bandwidth & information Information: –Current user location –Type and speed of connection device –Type of remote client or remote control software –Battery power –Memory

20. Wireless Transmission technology –Spread spectrum transmission –Infrared transmission Standards –IEEE 802.11 Mobil IP (client, home agent)

21. Spread Spectrum Transmission Frequency-hopping spread spectrum (FHSS) –Hops within the frequency range –Less interference –Good for mobile computing Direct-sequence spread spectrum (DSSS) –10 bits to data message for id –Complexity, cost, overhead to processing id –superior throughput

22. Wireless WAN Service Circuit-switched analog cellular CDPD (Cellular digital packet data) Private packet radio Enchanced paging and two-way messaging ESMR (enhanced specialized mobile radio) Microcellular spread spectrum PCS (personal communications services)

23. Selection Criteria of WAN Services Content Geographic scope Amount of data Urgency Compatibility with LAN

24. CDPD Transaction processing and database queries Pros: –Fast call setup –Inexpensive for short messages Cons: –Limited availability –Expensive for large file transfers

25. Circuit-switched Cellular Large file transfers and faxes Pros: –Widely available –Reasonable price for longer transaction Cons: –Longer call setup time –Expensive for short message

26. Private Packet Radio Short bursty messages and e-mail Pros: –Wide area –Connect to e-mail system Cons: –Proprietary networks –Expensive for large file transfer

28. Enhanced Paging or Two-way Messaging Guaranteed delivery Return receipt McCaw Cellular

29. Enhanced Specialized Mobile Radio One or two way Voice, paging, or message

30. Microcell Spread spectrum Internet E-mail

31. Analog Cellular Modems support cellular transmission at both ends Cellular enhanced modem at mobile telephone switching office (MTSO) Advanced mobile phone service 800 MHz

32. Digital Cellular Personal Communications Services Personal phone number PPN Standards –Time division multiple access (TDMA) –Code division multiple access (CDMA) No modem Social impact and changes

33. Assignment Review chapters 8-10 Read chapter 11