Office Automation

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Office Automation Intranets

• BUSS 909

Lecture 2 Data Communication Technologies
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Notices

• Assignment 1
• Pickup Assignment 1 Handout now
• Assistance with Assignment 1
• Buy a copy of Woodward-Krons book from UniCentre
  Bookshop (if available)
• Also refer to Academic Essay Writing Notes in
  Closed Reserve
• Pickup a copy of Learning Development Student
  Services Brochure and Timetable

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Agenda L909-02

• Data Communications Principles and Technologies
• in this lecture we consider only the Data
  Communications technologies relevant to Office
  Automation
• we will revisit this topic in subsequent lectures

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Agenda T909-01

• Writing for Commerce Essays and Case Studies
  (differs from the published schedule)

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Office Automation Overview
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Office Automation

• the greatest proportion of work involves
  information in textual form
• procedures
• reports
• memoes
• applies to
• service industries, bureaucracies, public sector
  organisations, and small-large private sector
  organisations

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Office Automation

• additionally, decision making (work about work)
  in any organisation is conducted in groups
• these groups almost always are involved in
  language activities (reading, writing etc)
• board room meetings
• brainstorming sessions
• formal reviews
• shareholders meetings

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Office Automation

• technologies called OA systems have been
  developed since the mid-1970s to cope with these
  kinds of work
• generally these systems are based on networks of
  various kinds (we review the various types and
  some standard terminology used to describe them
  this lecture)

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Office Automation

• these technologies at that time were very
  expensive (special hardware and software)
• the leader was Wang Computers
• by the mid 80s experimental systems were being
  researched to support group-based activities-
  this research is still ongoing (Nunamaker et al
  1991 40-61)

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Office Automation

• OA systems were augmented with systems that had
  similar functionality
• other names that can be found include OIS-
  Office Information Systems EMS- Electronic
  Meeting Systems Collaborative Management Systems

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Office Automation

• much of this has been superceded by developments
  in the marketplace- including proprietary
  integrated software eg. Lotus Notes Microsoft
  Office97
• also the WWW and graphical browsers provide a way
  for organisations to transform desktop computing
  to webtop computing

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Office Automation

• but the research that led to these systems is
  still relevant as we try to implement the same
  functionality in the form of intranets and
  extranets (private networks based on Internet
  technology)

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Office Automation

• an additional trend is to create the virtual
  organisation, which again is based on theory and
  principles established and developed during the
  mid-1970s
• telework, remote work, mobile data systems etc

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Network Processing Topologies
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Network Terms

• topology pattern of a network
• circuit
• transmission facility provides gt1 channels of
  communication eg/ phone line, microwave signal,
  optical cable
• node
• point in a network where circuits are
  interconnected by one or more units
• may be other computers

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Network Processing (1)

• Timesharing Networks
• oldest approach
• introduced in 3rd generation
• consists of a single computer
• performance limited to the computer

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Network Processing (2)

• Distributed Processing
• when minicomputers became popular
• companies started distributing minis and micros
  throughout the organisation
• when interconnected the technique is called
  distributed computing or distributed data
  processing (DDP)

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Network Processing (3)

• Client/Server Computing
• some functions are best handled locally and some
  are best handled centrally
• blend of timesharing approach (central use) and
  distributed processing (local)
• usually LANs but can be WANs
• client user has access to network by means of
  desktop computer
• server computer of any size which provides
  control of network function

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Network Topologies (1)

• describes how multiple computers are connected
  together (eg/ distributed processing,
  client/server computing) on a network
• several different topologies are available

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Network Topologies (2)

• Star Network
• central computer called the central node
• guarentees centralised control
• failure on central node causes failure over
  entire network

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Network Topologies (3)

• Ring Network
• does not include a central node
• control is distributed throughout network
• failure in any link causes problem for network
• Hybrid Network
• star rings can be used together
• when this occurs the topology is referred to as a
  Hybrid Topology

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Network Management, Planning Control
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Network Management (1)

• often critical to firms
• network failures can be catastropic
• require planning and control
• need to be managed
• What would happen if a your banks ATM data
  comms network fails ?

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Network Management (2)

• in large companies
• network manager
• network analysts
• software analysts
• datacom technicians
• in small companies
• LAN manager

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Network Management (3)

• Network Manager
• responsible for
• planning
• implementing
• operating
• controlling
• responsible to CIO

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Network Management (4)

• Network Analyst
• perform same function as systems analysts
• restricted to communication-oriented systems
• Software Analysts
• program maintain datacom software

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Network Management (5)

• Datacom technicians
• concerned with hardware and operations
• LAN Manager
• found in smaller organisations
• members of information services
• generally a member of using organisation
• may perform all of the duties of network manager

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Network Planning

• all activities that aim to anticipate firms
  networking needs
• Capacity planning
• analyses plans for traffic volumes
• Staff planning
• people to manage network skills
• Performance monitoring
• analyse response times and potential changes

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Network Control

• day-to-day monitoring of the network
• involves fault detection, fault isolation,
  network restoration
• firm needs standard procedures to implement
  network control

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Network Architectures
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Network Architectures (1)

• variety of hardware software
• products available from
• computer manufacturers
• common carriers
• data coms specialist companies
• many suppliers standards is a mixed blessing

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Network Architectures (2)

• network architectures specify protocols
• rule for interfacing (interconnecting) various
  units
• all data coms devices will follow specific
  protocols
• variety of units led to a small number of
  industry standards

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Network Architectures (3)

• Industry standards include
• SNA (IBM)
• BNA (Burroughs)
• DSE (Honeywell)
• One of the most common data coms standards is
  called OSI

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Network Architectures (4)

• SNA
• Systems Network Architecture
• developed by IBM because it marketed 200
  different data coms products
• one of the first standards developed
• a proprietary standard

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Network Architectures (5)

• SNA
• defines all activities involved in transmitting
  data through a network
• transmitted from a user node
• transmitted to a host node
• transmitted through one or more intermediate nodes

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Network Architectures (6)

• separates physical activities that transmit data
• and logical activities that control transmission

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Network Architectures (7)

• SNA
• classifies logical activities into layers
• layers insulate users from changes in the datacom
  hardware and software
• layers have become a common strategy in other
  datacoms standards

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OSI Model
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OSI Model (1)

• OSI Open Systems Interconnection
• almost all Network rely upon this Model to
  organise communications between Clients and
  Servers
• uses layers like SNA to define physical and
  logical layers
• 7 layers are used all nodes have them

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OSI Model (2)

• A layer at one node (user) talks to its
  corresponding layer at the other (host) end
• Layers 1-3 needed at every node Layers 4-7 at
  host user nodes only

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OSI Model (3)

• 1 Physical Layer
• Transmits the data from one node to another
• eg./ RS232c
• 2 Data Link Layer
• Formats the data into a record called a frame
• Performs error detection

Frame Check
Address
Control
Message
Ending Flag
Beginning Flag
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OSI Model (4)

• 3 Network Layer
• causes the physical layer to transfer the frames
  from node to node
• 4 Transport Layer
• enables user and host nodes to communicate with
  each other
• synchronizes fast- and slow- speed equipment as
  well as overburdened and idle units

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OSI Model (5)

• 5 Session Layer
• initiates, maintains and terminates each session
• sessions consist of all frames that comprise an
  activity, and all signals that identify beginning
  and end
• eg./ log-on and user id routines to initiate
  sessions

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OSI Model (6)

• 6 Presentation Layer
• formats data for presenting to user or host
• eg./ information to be displayed on users screen
  is formatted into proper number of screen lines
  and characters per line
• 7 Application Layer
• controls user input from the terminaland executes
  the users application program

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OSI Model (7)

• Eg./ User needs host software
• L7 (application) takes request
• L6 (presentation) changes input data to correct
  format for transmission
• L5 (session) starts the session on the host
  machines
• L4 (transport) selects route from user to host
• L3 2 (network data link) cause data to be
  transmitted through L1 (physical)

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OSI Model (8)
USER
HOST

• 7 Application Layer
• consists of application programs that use the
  network
• 6 Presentation Layer
• standardises data presentation to applications
• 5 Session Layer
• manages sessions between applications
• 4 Transport Layer
• provides end-to-end error detection and
  correction
• 3 Network Layer
• manages connections across the network for the
  upper layers
• 2 Data Link Layer
• provides reliable data delivery across the
  physical link
• 1 Physical Layer
• defines the physical characteristics of the
  network media

High
High
Low
Low
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OSI Model (9)
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Web Clients ServersSource Yeager McGrath
(1996, 11-16)
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Internet

• Internet (Internetworking) collection of
  computer networks and to allow interoperability
  between them
• networks can consist of many types of network
  technologies, protocols, and computers
• Several protocols are required for transmitting
  data across the Internet (TCP/IP)

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InternetInternet Protocol

• IP manages the transfer of data across physically
  distinct networks
• transfers data into packets within an envelope
  that describing its source and destination
• a message is in effect shattered into pieces,
  packaged as packets in envelopes, and burst
  transmitted to the destination
• IP looks after delivering these packages- one
  packet at a time!

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InternetTransmission Control Protocol

• networks are unreliable and IP does not guarantee
  that all pieces arrive (no notion of a
  connection)
• TCP defines conventions that make sure the pieces
  arrive in the correct order- by specifying
  another envelope around the data packets
• IP layer moves packets, TCP manages the connection

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InternetOther Services Protocols

• the layering or encapsulation which is a
  characteristic of OSI also works in much the same
  way with other services supported by the Internet
  (TCP/IP)
• File Transfer Protocol defines the conventions
  which describe how computers can cooperate in
  order to copy files from one computer to another
  on the Internet- it uses TCP/IP to do this

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InternetOther Services Protocols
Internet Protocol Transmission Control Protocol
File Transfer Protocol
FTP
FTP
TCP
TCP
Physical Network
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InternetWeb Services Protocols

• the web is just another internet service!
• Hypertext Transfer Protocol (HTTP) is the set of
  rules for making and fulfilling web requests
• however, the web is also designed to encapsulate
  other protocols including FTP, Gopher, WAIS,
  telnet and NNTP- we will talk about these
  services latter

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InternetWeb Services

• works as a client-server- in terms of services
  not necessarily hardware
• differs from other network models (terminal to
  mainframe and peer-to-peer) because client and
  server are independent, fully functional computer
  systems in their own right

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InternetWeb Services
email
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Intranets OASuccess of WWW- Open Standards

• machines on the Internet are effectively
  decentralised
• an important aspect of the web is that it is a
  set of open (not proprietary) protocols
• Uniform Resource Locators URLs
• Hypertext Transfer Protocol (HTTP)
• Hypertext Markup Language (HTML)

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Intranets OASuccess of WWW- Specific Issues

• web protocols are general enough to be
  implemented on any computer
• web application are the topmost layer in the
  Internet protocol hierarchy
• complex processes of transfer of data are
  hidden from the web application developer and
  user
• as a consequence there is a great variety of web
  applications available

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Web Servers ClientsSource Yeager McGrath
(1996, 11-16)
Web
Web
FTP
FTP
TCP
TCP
Physical Network
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Summary
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Intranets OAFailure of OA- Proprietary
Technologies

• OA did not become very important because they
  were based on proprietary technologies
• implies closed technologies and markets-
  ultimately counter-productive!
• slow development time, large market lags, small
  client bases, under utilised technology,
  increased expense in setup, use, maintenance,
  upgrade

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Intranets OAFailure of OA- Specific Issues

• data sometimes had to be re-entered- proprietary
  technologies mean that other vendors dont have
  the technical information needed to write
  transfer routines
• had to rely on the vendor to keep the technology
  current- there development team is the only one
  available to service your needs
• incompatibilities- cant supplement the OA
  vendors equipment with other vendors products

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From OSI to TCP/IP

• TCP/IP
• 4 Application Layer
• consists of applications and processes that use
  the network
• 3 Host-to-Host Transport Layer
• provides end-to-end data delivery services
• 2 Internet Layer
• defines the datagram and handles the routing of
  data
• 1 Network Access Layer
• consists of routines for accessing physical
  networks

• OSI
• 7 Application Layer
• 6 Presentation Layer
• 5 Session Layer
• 4 Transport Layer
• 3 Network Layer
• 2 Data Link Layer
• 1 Physical Layer

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Next Week

• Lecture (L909-03)
• Office Automation Systems Computer supported
  Cooperative Work/Groupware
• Tutorial (T909-02)
• Search Engines Techniques (differs from
  Tutorial Schedule)