1. COMP1321 Digital Infrastructure Richard Henson January 2016

2. Week 12: Overview of Important LAN Operating Systems Objective: Objective:  Name significant network operating systems in developments towards today’s organisational networks  Briefly explain features of proprietary products that fulfil particular requirements of a network operating system  Explain a (network) operating system architecture in terms of a multi-layered model

3. Operating Systems for Ethernet Networks Original Topology (1980s, early 90s): Original Topology (1980s, early 90s):  bus, coaxial cable & BNC connectors (!) DOS? DOS?  No way! not designed for: server end stuffserver end stuff distributed communicationsdistributed communications security…security…

4. Operating Systems for Ethernet Networks  Two popular client-server operating systems emerged: Novell NetwareNovell Netware n IPX/SPX protocol n not OSI compliant - proprietary & code secret DEC (Digital) PCSADEC (Digital) PCSA n DECnet protocol n OSI & TCP/IP compliant - code open source

5. Netware - late 1980s Novell’s proprietary IPX/SPX network protocol Novell’s proprietary IPX/SPX network protocol  network naming based on MAC address hardwired into network card during manufacturehardwired into network card during manufacture Also, MHS protocol for message- handling and email within the LAN Also, MHS protocol for message- handling and email within the LAN

6. Novell Netware Cool Server stuff… Cool Server stuff…  secure file system based on user, groups, rights & inherited rights  supported mirroring, duplexing, RAID  TTS to reverse incomplete transactions  network resource names, etc. stored as a separate bindery on each server

7. Other Features of Netware I/O optimisation: I/O optimisation:  disk caching  elevator seeking (disk accesses ordered according to position on disk)  directory hashing

8. Strengths of Netware  Fast MAC address not IP, fewer headers, less processing of packetsMAC address not IP, fewer headers, less processing of packets  Secure awarded US gov Server Fault Tolerance (SFT) grade IIIawarded US gov Server Fault Tolerance (SFT) grade III n when used with server duplexing

9. Enduring Problems with Netware Only ran on Intel Platform Only ran on Intel Platform Reliant on DOS/Windows at the client end Reliant on DOS/Windows at the client end NDS (Directory Structure) not X500 compliant NDS (Directory Structure) not X500 compliant Not directly compatible with TCP/IP Not directly compatible with TCP/IP  interprocess communication based on IPX/SPX  used MAC addresses (fixed on network card) as unique identifiers, rather than IP addresses Not suitable for peer-peer networking Not suitable for peer-peer networking Not pre-emptive in handling processes Not pre-emptive in handling processes

10. What happened to Netware? V.successful in early 1990s V.successful in early 1990s  better sales than DEC PCSA architecture, even though the latter was OSI compliant (!!) SPX/IPX faster than TCP/IP…SPX/IPX faster than TCP/IP…  70% of the PC network market

11. What happened to Netware Didn’t see what was coming (Microsoft!)… Didn’t see what was coming (Microsoft!)…  DEC mini computers lost market share everyone wanted a PC networkeveryone wanted a PC network main LAN rival DEC was being sold off and “asset stripped”main LAN rival DEC was being sold off and “asset stripped” future looked brightfuture looked bright  BUT… by 1998, Novell Netware sales were sunkby 1998, Novell Netware sales were sunk by 2000, even Oracle stopped supporting themby 2000, even Oracle stopped supporting them only kept in business by merging with Red Hat Linuxonly kept in business by merging with Red Hat Linux

12. More on DEC (Digital Equipment) World’s most innovative computer company for many years… World’s most innovative computer company for many years…  as already stated - first minicomputer: PDP-1 (Programmable Data Processor)PDP-1 (Programmable Data Processor)  first UNIX/C implementation On PDP-5On PDP-5

13. DEC continued… Most successful minicomputer: Most successful minicomputer:  VAX (Virtual Address eXtension) First virtual memory operating system First virtual memory operating system  VMS (virtual memory system) for VAX First commercially successful RISC chip First commercially successful RISC chip  alpha First commercial Internet domain & website First commercial Internet domain & website First successful search engine: AltaVista First successful search engine: AltaVista

14. Organisational Networks in 1990 Business/finance companies: Business/finance companies:  usually IBM networks Science/Technology/Engineering companies: Science/Technology/Engineering companies:  usually DEC networks Smaller companies (SME size...) Smaller companies (SME size...)  couldn’t justify/afford networks!

15. Where did DEC go? Second biggest computer company in the world in 1990! Second biggest computer company in the world in 1990!  over 100000 employees!  with early 90s recession, went into decline… New MD in 1992, only accelerated the decline New MD in 1992, only accelerated the decline  assets sold one by one… unkindest cut – alpha chip to Intel in 1997unkindest cut – alpha chip to Intel in 1997  what was left (VMS) went to Compaq in 1998 sold on to HP…sold on to HP…

16. What happened? As with the downfall of IBM, Netscape and Novell… As with the downfall of IBM, Netscape and Novell…  out-manoeuvred in business  perhaps the name Microsoft might help…

17. Microsoft and VMS… Now long enough ago to be of historical interest… Now long enough ago to be of historical interest…  Dave Cutler, brains behind DEC’s VMS; http://en.wikipedia.org/wiki/Dave_Cutler http://en.wikipedia.org/wiki/Dave_Cutlerhttp://en.wikipedia.org/wiki/Dave_Cutler  went to work at Microsoft in 1988 to develop “a new operating system” (NT)…to develop “a new operating system” (NT)… DEC watching their mini-computers become “dinosaurs” (1990-93) DEC watching their mini-computers become “dinosaurs” (1990-93)  pinned hopes on new RISC chip (alpha)  keen to get their alpha chip onto the original Windows NT…

18. A tale of intellectual copyright (and smart business) DEC saw NT as their big opportunity to get into the PC server business DEC saw NT as their big opportunity to get into the PC server business  expected Alpha chip platform/Windows NT to be popular  signed away rights to Cutler & co’s code – code used in creating windows NT Microsoft effectively got the technologies behind VMS that they used for NT… for free!!!!Microsoft effectively got the technologies behind VMS that they used for NT… for free!!!! final insult… Intel platform preferred for servers (!)final insult… Intel platform preferred for servers (!) Thanks to HP, and enthusiastic users, VMS lives (!) Thanks to HP, and enthusiastic users, VMS lives (!)  available for download at: http://www.openvms.compaq.com/openvms/freewarehttp://www.openvms.compaq.com/openvms/freewarehttp://www.openvms.compaq.com/openvms/freeware

19. Microsoft & Network Operating Systems Whilst the US government was being defeated in the courts by IBM… Whilst the US government was being defeated in the courts by IBM…  a deal that almost put them out of business was pulled off by the young Bill Gates!  story about IBM negotiations with Bill Gates (regarding his mate Tim Paterson’s os): http://inventors.about.com/library/weekly/aa033099.htmhttp://inventors.about.com/library/weekly/aa033099.htmhttp://inventors.about.com/library/weekly/aa033099.htm  and the tragedy of Gary Kildall (creator of CP/M, main rival to DOS & one time business partner of Steve Jobs)… http://www.businessweek.com/magazine/content/04_43/b3 905109_mz063.htmhttp://www.businessweek.com/magazine/content/04_43/b3 905109_mz063.htmhttp://www.businessweek.com/magazine/content/04_43/b3 905109_mz063.htmhttp://www.businessweek.com/magazine/content/04_43/b3 905109_mz063.htm

20. DOS (Desktop Operating System) As was to be expected from a back-street deal… As was to be expected from a back-street deal…  DOS was an awful operating system…  no way it could be satisfactorily used for even multi-tasking, let alone networking…  no way of logging in as an authenticated user…logging in as an authenticated user… restricting access to resources…restricting access to resources…  to the new (misguided?) computer generation… none of this matterednone of this mattered  by the late 1980s Gates was the 4 th richest person in the world!

21. OS2, Windows, and Windows NT By late 1980s, PCs being used for serious business purposes By late 1980s, PCs being used for serious business purposes  IBM needed a serious operating system for the PC…  Microsoft worked them on OS2  still didn’t see Gates as a rival! At about the same time… At about the same time…  Cutler left DEC… joined Microsoft  scope for a virtual memory operating system… (Windows)(Windows)

22. Windows On the one hand On the one hand  Microsoft were working with IBM on OS2 One the other hand: One the other hand:  they were working on developing Windows and working with software developers to provide applications for Windows…and working with software developers to provide applications for Windows… n users want apps, not operating systems! Guess which one won??? Guess which one won???  you’ve got it… Microsoft now bigger than IBM

23. Rise of CISCO Emerged from Silicon Valley Emerged from Silicon Valley Success based on combination… Success based on combination…  Routers  software to manage routing arguments about ownershiparguments about ownership  further software development… n embraced OSI model (layers 1-3) n became preferred low level operating system: IOS

24. Packet Tracer Teaching Aid (huge cost-saving!) Teaching Aid (huge cost-saving!)  Students working towards Cisco Certified Network Associate (CCNA) certification teaches concepts of networking with simulationteaches concepts of networking with simulation designs new networks by connecting networking devices and running troubleshooting tests to check the connectivity and communicationdesigns new networks by connecting networking devices and running troubleshooting tests to check the connectivity and communication helps understand choice of different networking devices appropriatelyhelps understand choice of different networking devices appropriately