COMP1321COMP1321

Digital InfrastructureDigital Infrastructure

Richard HensonRichard Henson

February 2013February 2013

Week 12: Overview of Week 12: Overview of Important Network Important Network Operating SystemsOperating Systems

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

in developments towards today’s in developments towards today’s organisational networksorganisational networks

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

Explain a (network) operating system Explain a (network) operating system architecture in terms of a multi-layered modelarchitecture in terms of a multi-layered model

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?DOS?No way! not designed for:No way! not designed for:

• server end stuffserver end stuff• distributed communicationsdistributed communications• security…security…

Operating Systems for PC Operating Systems for PC Ethernet NetworksEthernet Networks

two popular client-server operating two popular client-server operating systems emerged:systems 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 & TCP/IP compliant - code open sourceOSI & TCP/IP compliant - code open source

Netware - late 1980sNetware - late 1980s

• Novell’s proprietary IPX/SPX network Novell’s proprietary IPX/SPX network protocolprotocolnetwork naming based on MAC addressnetwork naming based on MAC address

• hardwired into network card during hardwired into network card during manufacturemanufacture

• Also, MHS protocol for message-Also, MHS protocol for message-handling and email within the LANhandling and email within the LAN

Novell NetwareNovell Netware

• Cool Server stuff…Cool Server stuff…secure file system based on user, groups, secure file system based on user, groups,

rights & inherited rightsrights & inherited rightssupported mirroring, duplexing, RAIDsupported mirroring, duplexing, RAIDTTS to reverse incomplete transactionsTTS to reverse incomplete transactionsnetwork resource names, etc. stored as a network resource names, etc. stored as a

separate bindery on each serverseparate bindery on each server

Other Features of NetwareOther Features of Netware

• 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 hashing

Strengths of NetwareStrengths of Netware

FastFast• MAC address not IP, fewer headers, less MAC address not IP, fewer headers, less

processing of packetsprocessing of packets

SecureSecure• awarded US gov Server Fault Tolerance awarded US gov Server Fault Tolerance

(SFT) grade III(SFT) grade III when used with server duplexingwhen used with server duplexing

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 (Directory Structure) not X500 compliantNDS (Directory Structure) not X500 compliant

• Not directly compatible with TCP/IPNot directly compatible with TCP/IP interprocess communication based on IPX/SPXinterprocess communication based on IPX/SPX used MAC addresses (fixed on network card) as used MAC addresses (fixed on network card) as

unique identifiers, rather than IP addressesunique identifiers, rather 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 1990sbetter sales than DEC PCSA architecture, better sales than DEC PCSA architecture,

even though the latter was OSI compliant even 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

What happened to NetwareWhat happened to Netware

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

• everyone wanted a PC networkeveryone wanted a PC network• main LAN rival DEC was being sold off and “asset main LAN rival DEC was being sold off and “asset

stripped”stripped”• future looked brightfuture looked bright

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

More on DEC More on DEC (Digital Equipment)(Digital Equipment)

• World’s most innovative computer World’s most innovative computer company for many years…company for many years…as already stated - first minicomputer:as already stated - first minicomputer:

• PDP-1 (Programmable Data Processor)PDP-1 (Programmable Data Processor)

first UNIX/C implementationfirst UNIX/C implementation• On PDP-5On PDP-5

DEC continued…DEC continued…

• Most successful minicomputer:Most successful minicomputer: VAX (Virtual Address eXtension)VAX (Virtual Address 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

Organisational Networks Organisational Networks in 1990in 1990

•Business/finance companies:Business/finance companies:usually IBM networksusually IBM networks

•Science/Technology/Engineering Science/Technology/Engineering companies:companies:usually DEC networksusually DEC networks

•Smaller companies (SME size...)Smaller companies (SME size...)couldn’t justify/afford networks!couldn’t justify/afford networks!

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…

What happened?What happened?

• As with the downfall of IBM, Netscape As with the downfall of IBM, Netscape and Novell…and Novell…out-manoeuvred in businessout-manoeuvred in businessperhaps the name perhaps the name MicrosoftMicrosoft might help… might help…

Microsoft and VMS…Microsoft and VMS…• 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;Dave Cutler, brains behind DEC’s VMS;

• http://en.wikipedia.org/wiki/Dave_Cutler http://en.wikipedia.org/wiki/Dave_Cutler went to work at Microsoft in 1988went 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 DEC watching their mini-computers become “dinosaurs” (1990-93)become “dinosaurs” (1990-93)pinned hopes on new RISC chip (alpha)pinned hopes on new RISC chip (alpha)keen to get their alpha chip onto the original keen to get their alpha chip onto the original

Windows NT…Windows NT…

A tale of intellectual copyright A tale of intellectual copyright (and smart business)(and smart business)

• DEC saw NT as their big opportunity to get into DEC saw NT as their big opportunity to get into the PC server businessthe PC server business expected Alpha chip platform/Windows NT to be expected Alpha chip platform/Windows NT to be

popularpopular signed away rights to Cutler & co’s code – code signed away rights to Cutler & co’s code – code

used in creating windows NTused in creating windows NT• Microsoft effectively got the technologies behind VMS that Microsoft effectively got the technologies behind VMS that

they used for NT… for free!!!!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, Thanks to HP, and enthusiastic users, VMS lives (!)VMS lives (!) available for download at:available for download at:

• http://www.openvms.compaq.com/openvms/http://www.openvms.compaq.com/openvms/freeware freeware

Microsoft Microsoft & Network Operating Systems& Network Operating Systems

• Whilst the US government was being defeated Whilst the US government was being defeated in the courts by IBM…in the courts by IBM… a deal that almost put them out of business was a 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 story about IBM negotiations with Bill Gates

(regarding his mate Tim Paterson’s os):(regarding his 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, main rival to DOS & one time business partner of main rival to DOS & one time business partner of Steve Jobs)…Steve Jobs)…

• 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 As was to be expected from a back-street deal…deal… DOS was an awful operating system… DOS was an awful operating system… no way it could be satisfactorily used for even no way it could be satisfactorily used for even

multi-tasking, let alone networking…multi-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 4thth richest person richest person in the world!in 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… based on DOSWindows… based on DOS

virtual memory enabled multitaskingvirtual memory enabled multitasking but architecture fundamentally flawed…but architecture fundamentally flawed…

• Stopgap while new “serious” operating Stopgap while new “serious” operating system being developed…system being developed…

• 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 known as Windows 3.11 (for workgroups)known as 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 desktop product generation. The commercial desktop product was still basically DOS, but Gates now was still basically DOS, but Gates now offeredoffered peer-peer networking and a simple network peer-peer networking and a simple network

protocol (NETBEUI)protocol (NETBEUI) 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 NetwareWindows NT v Unix v Netware

•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 appsInternet ready but complex, & limited apps

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

weakness... (!)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

• Released late 1996 Released late 1996 Windows 95 interface & registryWindows 95 interface & registrymany www features, incl. IIS (web server)many www features, incl. IIS (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 usersnow became a major challenge to Netware now became a major challenge to Netware

(not TCP/IP compatible) & Unix (still not (not TCP/IP compatible) & Unix (still not enough apps)enough apps)

main problem: main problem: not scalablenot scalable

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

• Secure 32-bit kernel based on VMSSecure 32-bit kernel based on VMSremains intact to present dayremains intact to present daynow enhanced to 64-bitnow enhanced to 64-bit

• (but this was supposed to happen originally (but this was supposed to happen originally with “Windows 5”, to support DECs 64-bit with “Windows 5”, to support DECs 64-bit alpha-chipalpha-chip

• Separated kernel provided the Separated kernel provided the capability for NT, like Unix, to run on capability for NT, like Unix, to run on multiple platformsmultiple platformsguess who didn’t like that idea!guess who didn’t like that idea!

Windows NT ArchitectureWindows NT Architecture

• Supports pre-emptive multitasking & Supports pre-emptive multitasking & multithreadingmultithreadinggood for centralised controlgood for centralised control

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

• Applications have separate address Applications have separate address spaces (unlike DOS/Windows… crash!)spaces (unlike DOS/Windows… crash!)up to 4 Gb of memoryup to 4 Gb of memoryup 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 code outside the kernel was much code outside the kernel was

new; bugs had to be ironed outnew; bugs had to be ironed outeach server had its own security each server had its own security

database; considerable problems for database; considerable problems for scalabilityscalability

Windows 2000Windows 2000

• The big one!!!The big one!!!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• Microsoft technologies with Internet Microsoft technologies with Internet

technologiestechnologiesYet 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” (client-Microsoft’s own “history of Windows” (client-

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

winhistorydesktop.mspxwinhistorydesktop.mspx

Windows 2000Windows 2000

• ScalableScalableActive DirectoryActive 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 arguably muchmuch better than NDS better than NDS• finished off Novell Netware…finished off Novell Netware…

Windows 2000Windows 2000

• Secure… (!)Secure… (!)secure remote authenticationsecure remote authentication

• with help from Active Directory…with help from Active Directory…

Kerberos (IETF, RFCs)Kerberos (IETF, RFCs)PKI-ready (IETF, RFCs)PKI-ready (IETF, RFCs)terminal servicesterminal services

• remote log on with minimal computing remote log on with minimal computing resourcesresources

More Recent OS More Recent OS DevelopmentsDevelopments

• Novell survived (as a company) by:Novell survived (as a company) 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… 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 (very) slowly gaining popularity…Linux (very) slowly gaining popularity…

Windows Server Windows Server Developments since 2000Developments since 2000

• 2003 Server2003 Server more improvements to active directorymore improvements to active directory 64-bit version available! 64-bit version available!

• 2008 Server2008 Server file system enhancementsfile system enhancements active directory:active directory:

• directory tree extendeddirectory tree extended• better management tools (larger networks)better management tools (larger networks)

• Although Bill Gates may have retired, Steve Cutler is Although Bill Gates may have retired, Steve Cutler is still with them (helped with “Azure” and now…Xbox)still with them (helped with “Azure” and now…Xbox) http://www.amd.com/us-en/assets/content_type/http://www.amd.com/us-en/assets/content_type/

DownloadableAssets/DownloadableAssets/Microsoft_Video_Statement.wmv Microsoft_Video_Statement.wmv

Client-side Developments…Client-side Developments…• Microsoft Domination…Microsoft Domination…

XP: finished off the evolution from Windows 95/98XP: finished off the evolution from Windows 95/98 Vista: mainly a desktop changeVista: mainly a desktop change

• not universally appreciated!not universally appreciated!• mobile devices started to have:mobile devices started to have:

CPUs & operating systems (!)CPUs & operating systems (!) user interfaces & use apps…user interfaces & use apps…

• Reaction to Vista…Reaction to Vista… Apple became popularApple became popular other “mobile” desktops became popularother “mobile” desktops became popular

• Windows 7 stopped the rot…Windows 7 stopped the rot…• Windows Mobile: good platform for appsWindows Mobile: good platform for apps

but Windows client-end dominance lost for but Windows client-end dominance lost for good…good…

So, which Server operating So, which Server operating system would the larger system would the larger company use today? company use today? • IBM, or other “mainframe”?IBM, or other “mainframe”?

why not?why not?

• Windows 2008 very popular with Windows 2008 very popular with finance industry & previous IBM finance industry & previous IBM customers!customers!

• Unix (incl Linux) popular with Unix (incl Linux) popular with previous DEC customersprevious DEC customers still cheaper than Windowsstill cheaper than Windows still more complicated, but suits still more complicated, but suits

companies that value and develop companies that value and develop technologiestechnologies

And the small business?And the small business?

• Lot of contradictory adviceLot of contradictory adviceuse Linux!use Linux!use Windowsuse WindowsDon’t bother?Don’t bother?

• use virtualisationuse virtualisation• outsourceoutsource• use The Clouduse The Cloud

• Who should they listen to? Why?Who should they listen to? Why?

And tomorrow?And tomorrow?

•Important for people involved in Important for people involved in procurement for and management procurement for and management of networksof networksWindows 2012 due (much change?)Windows 2012 due (much change?)Unix/Linux?Unix/Linux?others?others?

•Time to do a little research...Time to do a little research...