COMP2122 Network Operating Systems Richard Henson University of Worcester November 2010.

COMP2122 COMP2122 Network Operating SystemsNetwork Operating Systems

Richard HensonRichard Henson

University of WorcesterUniversity of Worcester

November 2010November 2010

Week 6: Overview of Week 6: Overview of Important Network Important Network Operating SystemsOperating Systems

•Objective:Objective: Name significant network operating systems in Name significant network operating systems in

developments towards today’s local area developments towards today’s local area networksnetworks

Briefly explain features of proprietary products Briefly explain features of proprietary products that fulfil particular requirements of a network that fulfil particular requirements of a network operating systemoperating system

Link operating system architectures to the Link operating system architectures to the seven layer modelseven layer model

Early Operating SystemsEarly Operating Systems

•Early computers were all unique and Early computers were all unique and had their own operating systemshad their own operating systems

• IBM designed & built the world’s first IBM designed & built the world’s first mass produced “mainframe”mass produced “mainframe” IBM 701 (1952)IBM 701 (1952)

• purchasers expected to write their own purchasers expected to write their own operating systems!operating systems!

• first “mass produced” operating system first “mass produced” operating system written by General Motors: GM-NAA I/O in written by General Motors: GM-NAA I/O in 19561956

adopted by IBM as IBSYSadopted by IBM as IBSYS

IBM hugely successful; by 1980s, IBM hugely successful; by 1980s, allegedly bigger than US government allegedly bigger than US government (?)(?)

First British Operating First British Operating systemsystem

•Leo 3 was the first mass produced Leo 3 was the first mass produced British ComputerBritish Computer 94 units built 1961-196994 units built 1961-1969

• full list of buyers full list of buyers http://www.leo-computers.org.uk/newleo3s.htmhttp://www.leo-computers.org.uk/newleo3s.htm

each had a loudspeaker connected to the each had a loudspeaker connected to the CPU… so operators could tell if it was CPU… so operators could tell if it was “looping”“looping”

had a multi-tasking operating system called had a multi-tasking operating system called “master program”“master program”

•some continued in service until 1981some continued in service until 1981

First Minicomputer & First Minicomputer & Operating systemOperating system

•Produced by Digital Equipment Produced by Digital Equipment Corporation (DEC) in 1963Corporation (DEC) in 1963 called the PDP-6called the PDP-6

• ““mini” in size compared to mainframesmini” in size compared to mainframes• huge by today's standardshuge by today's standards

operating system called “monitor”operating system called “monitor”• evolved into the TOPS10 (1970)evolved into the TOPS10 (1970)• ran on the legendary PDP-10ran on the legendary PDP-10• still going until 1988still going until 1988• can get it even now:can get it even now:• http://www.inwap.com/pdp10/96license.txthttp://www.inwap.com/pdp10/96license.txt

Unix Unix • Spin-off (1969) from project MULTICSSpin-off (1969) from project MULTICS

First attempt at a multiuser operating systemFirst attempt at a multiuser operating system• Consortium including Bell Labs, AT&T, Consortium including Bell Labs, AT&T,

US equivalent of BT at that timeUS equivalent of BT at that time

• FAILED! Too ambitious…FAILED! Too ambitious… Bell Labs: cut down derivation called UNICS -> UNIXBell Labs: cut down derivation called UNICS -> UNIX

• written in assembly language by written in assembly language by Ken ThompsonKen Thompson• sharing of processes also being explored in The ARPAnet sharing of processes also being explored in The ARPAnet

projectproject

• Commercial Challenge: Commercial Challenge: • DEC PDP-7 minicomputerDEC PDP-7 minicomputer

• needed a general purpose “time sharing” operating system needed a general purpose “time sharing” operating system for multiuser use… for multiuser use…

• their own os “monitor” had not yet matured into TOPS-10their own os “monitor” had not yet matured into TOPS-10

Thompson, Ritchie, Thompson, Ritchie, “B”, NB, “C” & Unix“B”, NB, “C” & Unix

• Thompson looking for a high-level language Thompson looking for a high-level language to develop a time sharing osto develop a time sharing os• briefly toyed with Fortranbriefly toyed with Fortran• worked with colleagueworked with colleague Dennis Ritchie Dennis Ritchie to create to create

their own higher level language – “B”, based on their own higher level language – “B”, based on BCPLBCPL

• http://cm.bell-labs.com/cm/http://cm.bell-labs.com/cm/cscs/who//who/dmrdmr//kbmankbman.html.html

• development of B = newB (NB)development of B = newB (NB)• development of NB -> Cdevelopment of NB -> C• Unix kernel was rewritten in “C” (1973)Unix kernel was rewritten in “C” (1973)

Development of Unix/CDevelopment of Unix/C

• ““C” compiler completed by Ritchie in 1972C” compiler completed by Ritchie in 1972

• Further commercial Unix versions (for Further commercial Unix versions (for Honeywell & IBM) released in 1973Honeywell & IBM) released in 1973

• ““C” further developed during 1973-7C” further developed during 1973-7

• Full definition of language as Kernighan & Full definition of language as Kernighan & Ritchie “C” (1978)Ritchie “C” (1978) rapidly gained universal acclaimrapidly gained universal acclaim

• Unix still written in “C” to present day!Unix still written in “C” to present day! 32-bit processing from the outset32-bit processing from the outset

Open Sourceness of UnixOpen Sourceness of Unix

• AT&T not allowed to be a commercial AT&T not allowed to be a commercial companycompany• could not sell Unixcould not sell Unix• gave a copy away free to any developer who gave a copy away free to any developer who

wanted to use it!wanted to use it!• many universities contributed to its developmentmany universities contributed to its development

• Result (in 1979): Unix version 7Result (in 1979): Unix version 7• still recognisable today!still recognisable today!

Silicon Valley, TCP/IP and UnixSilicon Valley, TCP/IP and Unix

• University of California created The ARPAnet University of California created The ARPAnet (1969)(1969)

• 1975 onwards: Berkeley, north of San 1975 onwards: Berkeley, north of San FranciscoFrancisco• hub for its own unique brand of Unix developmentshub for its own unique brand of Unix developments• start of “Silicon Valley” (IT hot spot around SF) start of “Silicon Valley” (IT hot spot around SF)

• ARPAnet teamARPAnet team• developed TCP/IPdeveloped TCP/IP• 1980, gained approval through RFC1980, gained approval through RFC• operating system that would support TCP/IP arrived operating system that would support TCP/IP arrived

in 1983…in 1983…• Berkeley Unix (v4.2) packaged with TCP/IP protocol stackBerkeley Unix (v4.2) packaged with TCP/IP protocol stack• Sun microsystems producing the hardware…Sun microsystems producing the hardware…

Bell Labs Unix becomes Bell Labs Unix becomes Commercial…Commercial…

• US Dept of Justice broke up AT&T in 1984US Dept of Justice broke up AT&T in 1984• Bell Labs then allowed to sell their Unix source Bell Labs then allowed to sell their Unix source

code…code…

• Fortunately for SCO (Santa Cruz Operations) Fortunately for SCO (Santa Cruz Operations) they had ported Bell Unix to Intel hardware they had ported Bell Unix to Intel hardware the previous year (!)the previous year (!)• SCO Unix for PC became a lucrative business SCO Unix for PC became a lucrative business

marketmarket• operating system provided security on a PC where operating system provided security on a PC where

DOS couldn’t…DOS couldn’t…

Bad days for Unix…Bad days for Unix…

• UNIX free by nature from outsetUNIX free by nature from outsetnot so on an Intel PC, thanks to SCO!!!not so on an Intel PC, thanks to SCO!!!Bell Labs jealously guarded the source Bell Labs jealously guarded the source

code…code…universities lost interestuniversities lost interest

• Unix became expensive to buy… and Unix became expensive to buy… and was still not user-friendly or easy to use was still not user-friendly or easy to use so even more expensive to own!so even more expensive to own!

LinuxLinux• From 1992 (Linus Torvalds, University of From 1992 (Linus Torvalds, University of

Helsinki) made free Unix possible again!Helsinki) made free Unix possible again! LINUX – based on his name…LINUX – based on his name…

• Took…Took… Stallman’s GNU open source Unix Stallman’s GNU open source Unix

• which Tanenbaum had developed into MINIX…which Tanenbaum had developed into MINIX… very stablevery stable secure file systemsecure file system very efficient, optimised codevery efficient, optimised code earlier versions ran on an Intel 486!earlier versions ran on an Intel 486!

• Still Unix, still a server-end systemStill Unix, still a server-end system for client-server networking, need client-end for client-server networking, need client-end

software:software:• e.g. Banyan VINESe.g. Banyan VINES

LinuxLinux

• Still freely available via Internet!Still freely available via Internet!

• Huge range of software tools for managing Huge range of software tools for managing UNIX networks available for downloadUNIX networks available for download

• Problems (compared to Windows):Problems (compared to Windows): not as easy to managenot as easy to manage limited on-screen helplimited on-screen help limited range of good application softwarelimited range of good application software not all hardware has UNIX/LINUX driver softwarenot all hardware has UNIX/LINUX driver software

SCO v Linux (more Unix SCO v Linux (more Unix lawsuits…)lawsuits…)

• SCO sued Linux in 2003 for misappropriation SCO sued Linux in 2003 for misappropriation of Unix System V codeof Unix System V code subsequently sued:subsequently sued:

• IBMIBM• Red Hat (Novell)Red Hat (Novell)• Anyone else commercially involved with LinuxAnyone else commercially involved with Linux

e.g DaimlerChryslere.g DaimlerChrysler

• US Court finally shut them up in August 2007 US Court finally shut them up in August 2007 by saying SCO had no rights to the code by saying SCO had no rights to the code Novell were using…Novell were using… Linux continues to be “free” to this day…Linux continues to be “free” to this day…

Unix Platforms in 2010…Unix Platforms in 2010…

• Typical hardwareTypical hardware SUN SPARCSUN SPARC not a PC!not a PC!

• Excellent as an Internet platformExcellent as an Internet platform very secure, if properly configuredvery secure, if properly configured

• software bugs mostly sorted out a long time ago…software bugs mostly sorted out a long time ago…• always used TCP/IP for machine-machine always used TCP/IP for machine-machine

communicationscommunications

• Server or standalone workstation modeServer or standalone workstation mode Linux/Intel favourite for workstation modeLinux/Intel favourite for workstation mode

Operating Systems for PC Operating Systems for PC Ethernet NetworksEthernet Networks

• Original Topology (1980s, early 90s):Original Topology (1980s, early 90s): bus, coaxial cable & BNC connectors (!) bus, coaxial cable & BNC connectors (!)

• DOS not designed for server end, or DOS not designed for server end, or distributed communications…distributed communications… two popular client-server operating systems two popular client-server operating systems

emerged:emerged:• Novell NetwareNovell Netware

IPX/SPX protocolIPX/SPX protocol not OSI compliant - proprietary & code secretnot OSI compliant - proprietary & code secret

• DEC (Digital) PCSADEC (Digital) PCSA DECnet protocolDECnet protocol OSI compliant - code open sourceOSI compliant - code open source

Novell Netware (version 3)Novell Netware (version 3)• Netware - late 1980sNetware - late 1980s

Novell’s proprietary IPX/SPX network protocolNovell’s proprietary IPX/SPX network protocol• networkID based on MAC addressnetworkID based on MAC address• hardwired into network card during manufacturehardwired into network card during manufacture

• Server end…Server end… client-server networking only (no peer-peer)client-server networking only (no peer-peer) secure file system based on user, groups, rights & secure file system based on user, groups, rights &

inherited rightsinherited rights supported mirroring, duplexing, RAIDsupported mirroring, duplexing, RAID TTS to reverse incomplete transactionsTTS to reverse incomplete transactions network resource names, etc. stored as a network resource names, etc. stored as a

separate bindery on each serverseparate bindery on each server

Other Features ofOther Features of• I/O optimisation:I/O optimisation:

disk cachingdisk cachingelevator seeking (disk accesses ordered elevator seeking (disk accesses ordered

according to position on disk)according to position on disk)directory hashingdirectory hashingMHS protocol for message-handling and MHS protocol for message-handling and

email within the LANemail within the LAN

Strengths/Weaknesses Strengths/Weaknesses of Netware 3of Netware 3

• Strengths:Strengths: fast and securefast and secure

• awarded Server Fault Tolerance (SFT) grade III, when awarded Server Fault Tolerance (SFT) grade III, when used with server duplexingused with server duplexing

• WeaknessesWeaknesses proprietary protocol, not peer-peerproprietary protocol, not peer-peer inadequate accounting servicesinadequate accounting services only 16-bit processing only 16-bit processing 250 user maximum250 user maximum each user needs to login to each servereach user needs to login to each server

Improvements (version 4)Improvements (version 4)• Scalable across serversScalable across servers

Using Network Directory Service (NDS)Using Network Directory Service (NDS) network info stored in a managed naming system as network info stored in a managed naming system as

a bindery across the whole networka bindery across the whole network security includes NDS attributessecurity includes NDS attributes

• LANalyser tool for analysing packets & LANalyser tool for analysing packets & identifying protocol problemsidentifying protocol problems

• Easier to use than v3: GUI-basedEasier to use than v3: GUI-based ssupported:upported:

• 32-bit processing32-bit processing• long filenames - like Windows 95 on long filenames - like Windows 95 on • SMP - symmetric multi-processing (2 processors) SMP - symmetric multi-processing (2 processors) • Up to 1000 usersUp to 1000 users• remote Network mgtremote Network mgt

Enduring Problems Enduring Problems with Netwarewith Netware

• Only ran on Intel PlatformOnly ran on Intel Platform

• Reliant on DOS/Windows at the client endReliant on DOS/Windows at the client end

• NDS not not X500 compliantNDS not not X500 compliant

• not directly compatible with Internet protocols not directly compatible with Internet protocols such as TCP/IPsuch as TCP/IP based on IPX/SPX protocol (OSI levels 3 and 4) for based on IPX/SPX protocol (OSI levels 3 and 4) for

interprocess communicationinterprocess communication used MAC addresses (fixed) as unique identifiers, used MAC addresses (fixed) as unique identifiers,

rather than IP addressesrather than IP addresses

• not suitable for peer-peer networkingnot suitable for peer-peer networking

• not pre-emptive in handling processesnot pre-emptive in handling processes

What happened to Netware?What happened to Netware?

• V.successful in early 1990sV.successful in early 1990s better sales than DEC PCSA architecture, even better sales than DEC PCSA architecture, even

though the latter was OSI compliant (!!)though the latter was OSI compliant (!!)• SPX/IPX faster than TCP/IP…SPX/IPX faster than TCP/IP…

70% of the PC network market70% of the PC network market

• Didn’t see what was coming…Didn’t see what was coming… DEC mini computers lost market shareDEC mini computers lost market share

• everyone wanted a PC networkeveryone wanted a PC network• main rival DEC sold off and “asset stripped”main rival DEC sold off and “asset stripped”

BUT…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

What was DEC?What was DEC?• World’s most innovative computer company World’s most innovative computer company

for many years…for many years… first minicomputer:first minicomputer:

• PDP-1 (Programmable Data Processor)PDP-1 (Programmable Data Processor) first UNIX/C implementationfirst UNIX/C implementation

• On PDP-5On PDP-5 most successful minicomputer:most successful minicomputer:

• VAX (Virtual Addresss eXtension)VAX (Virtual Addresss eXtension) first virtual memory operating systemfirst virtual memory operating system

• VMS (virtual memory system) for VAXVMS (virtual memory system) for VAX first commercially successful RISC chipfirst commercially successful RISC chip

• alphaalpha first commercial Internet domain & websitefirst commercial Internet domain & website first successful search engine: AltaVistafirst successful search engine: AltaVista

Where did DEC go?Where did DEC go?• Second biggest computer company in the Second biggest computer company in the

world in 1990!world in 1990! over 100000 employees!over 100000 employees! With early 90s recession, went into decline…With early 90s recession, went into decline…

• New MD in 1992, only accelerated the declineNew MD in 1992, only accelerated the decline assets sold one by one…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 1998what was left (VMS) went to Compaq in 1998

• sold on to HP…sold on to HP…• still support VMS (as OpenVMS) to present daystill support VMS (as OpenVMS) to present day

• Why?Why? as with the downfall of IBM and Novell…as with the downfall of IBM and Novell…

• perhaps the name perhaps the name MicrosoftMicrosoft might help… might help…

What went wrong with DEC?What went wrong with DEC?• Now long enough ago to be of historical Now long enough ago to be of historical

interest…interest… Dave Cutler, brains behind DEC’s VMS went to Dave Cutler, brains behind DEC’s VMS went to

work at Microsoft in 1988 to develop “a new work at Microsoft in 1988 to develop “a new operating system” (NT)operating system” (NT)

• DEC keen to get their alpha chip onto the original DEC keen to get their alpha chip onto the original Windows NT…Windows NT…

• signed away any rights to the code used in creating signed away any rights to the code used in creating windows NTwindows NT

• so Microsoft effectively got the technologies behind VMS so Microsoft effectively got the technologies behind VMS for free!!!!for free!!!!

• But thanks to HP, and enthusiastic users, But thanks to HP, and enthusiastic users, VMS livesVMS lives available for download at:available for download at:

• http://www.openvms.compaq.com/openvms/freewhttp://www.openvms.compaq.com/openvms/freewareare

Microsoft & Operating Microsoft & Operating SystemsSystems

• Original IBM PC operating system…Original IBM PC operating system… whilst the US government was being defeated in the whilst the US government was being defeated in the

courts by IBM…courts by IBM… the deal that almost put them out of business was the deal that almost put them out of business was

pulled off by the young Bill Gates…pulled off by the young Bill Gates…• story about IBM negotiations with Bill Gates (regarding his story about IBM negotiations with Bill Gates (regarding his

mate Tim Paterson’s os):mate Tim Paterson’s os): http://inventors.about.com/library/weekly/aa033099.htm http://inventors.about.com/library/weekly/aa033099.htm

• and the tragedy of Gary Kildall (creator of CP/M)…and the tragedy of Gary Kildall (creator of CP/M)… http://www.businessweek.com/magazine/content/04_43/http://www.businessweek.com/magazine/content/04_43/

b3905109_mz063.htm b3905109_mz063.htm

DOS (Desktop Operating System)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… DOS was an awful operating system… no way it could be satisfactorily used for even multi-no way it could be satisfactorily used for even multi-

tasking, let alone networking…tasking, let alone networking… no way of 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…to the new (misguided?) computer generation…• none of this matterednone of this mattered

by the late 1980s Gates was the 4by the late 1980s Gates was the 4 thth richest person in richest person in the world!the world!

OS2, Windows, OS2, Windows, and Windows NTand Windows NT

• By late 1980s, PCs being used for serious By late 1980s, PCs being used for serious business purposesbusiness purposes IBM needed a serious operating system for the IBM needed a serious operating system for the

PC…PC… Microsoft worked them on OS2 Microsoft worked them on OS2 still didn’t see Gates as a rival!still didn’t see Gates as a rival!

• At about the same time…At about the same time… Cutler left DEC… joined MicrosoftCutler left DEC… joined Microsoft scope for a virtual memory operating system…scope for a virtual memory operating system…

• (Windows)(Windows)

WindowsWindows

• On the one handOn the one handMicrosoft were working with IBM on OS2Microsoft were working with IBM on OS2

• One the other hand:One the other hand:they were working on developing Windowsthey were working on developing Windows

• and working with software developers to provide and working with software developers to provide applications for Windows…applications for Windows…

users want apps, not operating systems!users want apps, not operating systems!

• Guess which one won???Guess which one won???you’ve got it… Microsoft now bigger than IBMyou’ve got it… Microsoft now bigger than IBM

Windows NTWindows NT

• Windows was based on DOSWindows was based on DOS virtual memory enabled multitaskingvirtual memory enabled multitasking but fundamentally flawed…but fundamentally flawed…

• Intermediate towards a new “serious” Intermediate towards a new “serious” operating system…operating system…

• using DEC technology…using DEC technology…

• ““New Technology” operating system quietly New Technology” operating system quietly released in 1993released in 1993 as a disguised front end enhancement to Windows as a disguised front end enhancement to Windows

3.13.1• i.e. Windows 3.11 (for workgroups)i.e. Windows 3.11 (for workgroups)

NT ArchitectureNT Architecture

• Industry experts soon noticed that many Industry experts soon noticed that many features were surprisingly similar to VMS… features were surprisingly similar to VMS… oddity… VMS + 1 = WNT (!!)oddity… VMS + 1 = WNT (!!)

• But Microsoft’s customers were from a new But Microsoft’s customers were from a new generation. The commercial product was still generation. The commercial product was still basically DOS, but Gates now offeredbasically DOS, but Gates now offered peer-peer networking and a simple network peer-peer networking and a simple network

protocol (protocol ( user-friendly graphical interfaceuser-friendly graphical interface sharing resources on appssharing resources on apps even TCP/IP compatibility…even TCP/IP compatibility…

Flexibility of Windows NTFlexibility of Windows NT(followed the Unix pattern)(followed the Unix pattern)

Operating system kernel

hardware

Operating system functions & interface

Applications

Windows NT v Unix v Windows NT v Unix v NetwareNetware

•By 1994, three possible network By 1994, three possible network platforms:platforms:Novell: fast, proven, scalable, well Novell: fast, proven, scalable, well

established, but proprietary (NDS & established, but proprietary (NDS & IPX/SPX)IPX/SPX)

Unix: robust, scalable, open source & Unix: robust, scalable, open source & Internet ready but complex, & limited Internet ready but complex, & limited appsapps

Windows NT: neither robust nor scalableWindows NT: neither robust nor scalable• but Gates by now a past master at but Gates by now a past master at

exploiting weakness…exploiting weakness…

Progressive Development of Progressive Development of Windows NTWindows 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)

NT version 4NT version 4• Major leap forward, released late 1996 Major leap forward, released late 1996

Windows 95 interfaceWindows 95 interface many www features, incl web servermany www features, incl web server

• Server end:Server end: designed to support server applications designed to support server applications

• no theoretical limit to number of usersno theoretical limit to number of users now a major challenge to Netware (not TCP/IP now a major challenge to Netware (not TCP/IP

compatible) & Unix (still not enough apps)compatible) & Unix (still not enough apps) main problem: not scalablemain problem: not scalable

• Client end (Workstation/Professional version)Client end (Workstation/Professional version) designed for client machines or secure peer-peer designed for client machines or secure peer-peer

networks (upgrade of Windows for Workgroups)networks (upgrade of Windows for Workgroups) connectivity now uses TCP/IP as defaultconnectivity now uses TCP/IP as default max 10 concurrent sessionsmax 10 concurrent sessions

The 32-bit Windows NT The 32-bit Windows NT architecturearchitecture

• Secure kernel based on VMSSecure kernel based on VMS available for multiple platformsavailable for multiple platforms

• Supports pre-emptive multitasking & Supports pre-emptive multitasking & multithreadingmultithreading

• Secure file system (NTFS)Secure file system (NTFS)

• Applications have separate address spacesApplications have separate address spaces up to 4 Gb of memoryup to 4 Gb of memory up to 16 Eb of disk space (1Eb = 2up to 16 Eb of disk space (1Eb = 260 60 bytes)bytes)

NT architecture (continued)NT architecture (continued)

• Server products have scope for Server products have scope for huge additional functionality…huge additional functionality…offered as servicesoffered as services

• Problems:Problems:much of the code in NT 4 was new, much of the code in NT 4 was new,

and bugs had to be ironed outand bugs had to be ironed outeach server had its own security each server had its own security

database which created considerable database which created considerable problems for scalabilityproblems for scalability

Windows 2000Windows 2000

• Further big jumpFurther big jump Designed to merge:Designed to merge:

• peer-peer networking capabilities of Windowspeer-peer networking capabilities of Windows• client-server requirements of LANsclient-server requirements of LANs

• Yet could still work with “DOS-based” i.e. Yet could still work with “DOS-based” i.e. Windows 3.x/95/98 clientsWindows 3.x/95/98 clients Microsoft’s own “history of Windows” Microsoft’s own “history of Windows”

(client-end/desktop versions):(client-end/desktop versions): http://www.microsoft.com/windows/http://www.microsoft.com/windows/

winhistorydesktop.mspxwinhistorydesktop.mspx

Windows 2000Windows 2000

• Added functionality:Added functionality: ScalableScalable

• active directoryactive directory X500 compliant directory serviceX500 compliant directory service enterprise-wide security & resource-sharingenterprise-wide security & resource-sharing

• arguably better than NDSarguably better than NDS finished off Novell Netware…finished off Novell Netware…

SecureSecure• secure remote authentication secure remote authentication • KerberosKerberos• PKI-readyPKI-ready• terminal servicesterminal services

remote log on with minimal computing resourcesremote log on with minimal computing resources

More Recent OS More Recent OS DevelopmentsDevelopments

• Novell survived by:Novell survived by: merging with developers of Linuxmerging with developers of Linux continuing to support “legacy” Netware systemscontinuing to support “legacy” Netware systems

• HP kept VMS customer base…HP kept VMS customer base… still developing as OpenVMS:still developing as OpenVMS:

• http://h71000.www7.hp.com/openvms/3http://h71000.www7.hp.com/openvms/30th/index.html0th/index.html

Once DEC alpha chip was history, developed Once DEC alpha chip was history, developed new Intel-based hardware platform (Integrity) to new Intel-based hardware platform (Integrity) to interface with VMS kernelinterface with VMS kernel

• Linux slowly gaining popularity…Linux slowly gaining popularity…

More recent OS developmentsMore recent OS developments• Microsoft has continued to improve NT:Microsoft has continued to improve NT:

Server-endServer-end• Windows 2003 Server, 64-bit! Windows 2003 Server, 64-bit! • Windows Windows 20082008 ServerServer

Client endClient end• VistaVista• Windows 7Windows 7

And although Bill Gates has now retired, Steve Cutler is still there… And although Bill Gates has now retired, Steve Cutler is still there… VIDEO:VIDEO:

• http://www.amd.com/us-en/assets/content_type/DownloadableAssets/Mhttp://www.amd.com/us-en/assets/content_type/DownloadableAssets/Microsoft_Video_Statement.wmvicrosoft_Video_Statement.wmv

• Desktop changes:Desktop changes: ever smallerever smaller mobile devices also have CPUs & operating systemsmobile devices also have CPUs & operating systems also have user interfaces & use apps…also have user interfaces & use apps…

So, which network operating So, which network operating system would you use today?system would you use today?

•NT, VMS, or a variety of UnixNT, VMS, or a variety of Unix

•Time to do some research… Time to do some research…