COMP1321COMP1321

Digital InfrastructureDigital Infrastructure

Richard HensonRichard HensonJanuary 2016January 2016

Week 12: Overview of Week 12: Overview of Important LAN Operating Important LAN Operating

SystemsSystems•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 Operating Systems for 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 Operating Systems for 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 packetsSecureSecure

• 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 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 used signed away rights to Cutler & co’s code – code used

in creating windows NTin 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/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

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/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 hand

Microsoft 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

Rise of CISCORise of CISCO•Emerged from Silicon ValleyEmerged from Silicon Valley

•Success based on combination…Success based on combination…RoutersRouterssoftware to manage routingsoftware to manage routing

• arguments about ownershiparguments about ownershipfurther software development…further software development…

embraced OSI model (layers 1-3)embraced OSI model (layers 1-3) became preferred low level operating system: IOSbecame preferred low level operating system: IOS

Packet Tracer Packet Tracer •Teaching Aid (huge cost-saving!)Teaching Aid (huge cost-saving!)

Students working towards Cisco Certified Students working towards Cisco Certified Network Associate (CCNA) certificationNetwork Associate (CCNA) certification• teaches concepts of networking with simulationteaches concepts of networking with simulation• designs new networks by connecting designs new networks by connecting

networking devices and running networking devices and running troubleshooting tests to check the connectivity troubleshooting tests to check the connectivity and communicationand communication

• helps understand choice of different networking helps understand choice of different networking devices appropriatelydevices appropriately