1. Week 13: Windows Networks By the end of this session, you should be able to: By the end of this session, you should be able to:  Explain the basic architecture of Windows Server architecture  Compare Windows Servers with other contemporary server operating systems for a variety of business purposes

2. Windows NT Windows… based on DOS Windows… based on DOS  virtual memory enabled multitasking  but architecture fundamentally flawed… Stopgap while new “serious” operating system being developed… Stopgap while new “serious” operating system being developed… using DEC technology…using DEC technology…  “New Technology” operating system quietly released in 1993  as a disguised front end enhancement to Windows 3.1  known as Windows 3.11 (for workgroups)

3. NT Architecture Industry experts soon noticed that many features were surprisingly similar to VMS… Industry experts soon noticed that many features were surprisingly similar to VMS…  oddity… VMS + 1 = WNT (!!) But Microsoft’s customers were from a new generation. The commercial desktop product was still basically DOS, but Gates now offered But Microsoft’s customers were from a new generation. The commercial desktop product was still basically DOS, but Gates now offered  peer-peer networking and a simple network protocol (NETBEUI)  user-friendly graphical interface  sharing resources on apps  even TCP/IP compatibility…

4. Flexibility of Windows NT (followed the Unix pattern) Operating system kernel hardware Operating system functions & interface Applications

5. Windows NT v Unix v Netware By 1994, three possible network platforms: By 1994, three possible network platforms:  Novell: fast, proven, scalable, well established, but proprietary (NDS & IPX/SPX)  Unix: robust, scalable, open source & Internet ready but complex, & limited apps  Windows NT: neither robust nor scalable but Gates by now a past master at exploiting weakness... (!)but Gates by now a past master at exploiting weakness... (!)

6. Progressive Development of Windows NT os kernel (diff versions of NT available for diff CPUs) range of CPUs, motherboards Operating system functions & interface (Windows) Applications (Windows apps -> NT apps)

7. NT version 4 Released late 1996 Released late 1996  Windows 95 interface & registry  many www features, incl. IIS (web server) Server end: Server end:  designed to support server applications no theoretical limit to number of usersno theoretical limit to number of users  now became a major challenge to Netware (not TCP/IP compatible) & Unix (still not enough apps)  main problem: not scalable

8. The 32-bit Windows NT architecture Secure 32-bit kernel based on VMS Secure 32-bit kernel based on VMS  remains intact to present day  now enhanced to 64-bit (but this was supposed to happen originally with “Windows 5”, to support DECs 64-bit alpha-chip(but this was supposed to happen originally with “Windows 5”, to support DECs 64-bit alpha-chip Separated kernel provided the capability for NT, like Unix, to run on multiple platforms Separated kernel provided the capability for NT, like Unix, to run on multiple platforms  guess who didn’t like that idea!

9. Windows NT Architecture Supports pre-emptive multitasking & multithreading Supports pre-emptive multitasking & multithreading  good for centralised control Secure file system (NTFS) Secure file system (NTFS) Applications have separate address spaces (unlike DOS/Windows… crash!) Applications have separate address spaces (unlike DOS/Windows… crash!)  up to 4 Gb of memory  up to 16 Eb of disk space (1Eb = 2 60 bytes)

10. NT architecture (continued) Server products have scope for huge additional functionality… Server products have scope for huge additional functionality…  offered as services Problems: Problems:  much code outside the kernel was new; bugs had to be ironed out  each server had its own security database; considerable problems for scalability

11. Windows 2000 The big one!!! The big one!!!  Designed to merge: peer-peer networking capabilities of Windowspeer-peer networking capabilities of Windows client-server requirements of LANsclient-server requirements of LANs Microsoft technologies with Internet technologiesMicrosoft technologies with Internet technologies  Yet could still work with “DOS-based” i.e. Windows 3.x/95/98 clients Microsoft’s own “history of Windows” (client- end/desktop versions):Microsoft’s own “history of Windows” (client- end/desktop versions): n http://www.microsoft.com/windows/winhistorydesktop.mspx http://www.microsoft.com/windows/winhistorydesktop.mspx http://www.microsoft.com/windows/winhistorydesktop.mspx

12. Windows 2000 Scalable Scalable  Active Directory X500 compliant directory serviceX500 compliant directory service even developed with aid of RFCseven developed with aid of RFCs multiple domainsmultiple domains enterprise-wide security & resource-sharingenterprise-wide security & resource-sharing  arguably much better than NDS finished off Novell Netware…finished off Novell Netware…

13. Windows 2000 Secure… (!) Secure… (!)  secure remote authentication with help from Active Directory…with help from Active Directory…  Kerberos (IETF, RFCs)  PKI-ready (IETF, RFCs)  terminal services remote log on with minimal computing resourcesremote log on with minimal computing resources

14. More Recent OS Developments CISCO grew with Microsoft NT series… CISCO grew with Microsoft NT series… Novell survived (as a company) by: Novell survived (as a company) by:  merging with developers of Linux  continuing to support “legacy” Netware systems HP kept VMS customer base… HP kept VMS customer base…  once DEC alpha chip was history, developed new Intel-based hardware platform (Integrity) to interface with VMS kernel Linux (very) slowly gaining popularity… Linux (very) slowly gaining popularity…

15. Windows Server Developments since 2000 2003 Server 2003 Server  more improvements to active directory  64-bit version available! 2008 Server 2008 Server  file system enhancements  active directory: directory tree extendeddirectory tree extended better management tools (larger networks)better management tools (larger networks) Although Bill Gates retired, Steve Cutler is still there (helping with “Azure”, Xbox, etc…) Although Bill Gates retired, Steve Cutler is still there (helping with “Azure”, Xbox, etc…)  http://www.amd.com/us- en/assets/content_type/DownloadableAssets/Micr osoft_Video_Statement.wmv http://www.amd.com/us- en/assets/content_type/DownloadableAssets/Micr osoft_Video_Statement.wmv http://www.amd.com/us- en/assets/content_type/DownloadableAssets/Micr osoft_Video_Statement.wmv

16. Client-side Developments… Microsoft Domination… Microsoft Domination…  XP: finished off the evolution from Windows 95/98  Vista: mainly a desktop change not universally appreciated!not universally appreciated! mobile devices started to have:mobile devices started to have: n CPUs & operating systems (!) n user interfaces & use apps… Reaction to Vista… Reaction to Vista…  Apple became popular  other “mobile” desktops became popular Windows 7 stopped the rot… Windows 7 stopped the rot… Windows Mobile: good platform for apps Windows Mobile: good platform for apps  but Windows client-end dominance lost for good…

17. Server operating systems for the larger company today… IBM, or other “mainframe”? IBM, or other “mainframe”?  why not? Windows 2008 & 2012 Server very popular with finance industry & previous IBM customers! Windows 2008 & 2012 Server very popular with finance industry & previous IBM customers! Unix (incl Linux) popular with previous DEC customers Unix (incl Linux) popular with previous DEC customers  still cheaper than Windows  still complicated, but suits companies that value and develop technologies

18. And the small business? Lot of contradictory advice Lot of contradictory advice  use Linux!  use Windows  Don’t bother? use virtualisationuse virtualisation use BYOD (or don’t!)use BYOD (or don’t!) outsourceoutsource use The Clouduse The Cloud Who should they listen to? Why? Who should they listen to? Why?

19. And tomorrow? Important for people involved in procurement for and management of networks Important for people involved in procurement for and management of networks  Windows 2016 due (much change?)  Unix/Linux?  others? Time to do a little research... Time to do a little research...