2. Introduction
An IT architecture is a blueprint.
A blueprint shows how a system, house, vehicle, or product will
look and how the parts interrelate.
An IT infrastructure is the implementation of an architecture.
The IT infrastructure includes the processors, software,
databases, electronic links, and data center as well as the
standards that ensure the components work together, the skills
for managing the operation etc.
Telecommunications is the flow of information among individuals,
work groups, departments, customer sites, regional offices,
between enterprises, and with the outside world.
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3. 3.2. Distributed systems: overall architecture
Four Attributes of Distributed Systems
Degree to which a system is distributed can be determined by
answering four questions:
Where is the processing done?
How are the processors and other devices interconnected?
Where is the information stored?
What rules or standards are used?
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4. Where is the processing done?
Distributed processing is the ability for more than one
interconnected processor to be operating at the same time,
typically for processing an application on more than one
computer at a time.
Goal: move the appropriate processing as close to the user
as possible and to let other machines handle the work they
do best.
Two forms of interoperability (capability for different
machines to work together on tasks):
Communication between systems
Two-way flow between user applications 4
5. How are the processors and other devices
interconnected?
Connectivity among processors means that each
processor in a distributed system can send data and
messages to any other processor through electronic
communication links
Desirable to have at least two independent paths
between two nodes to provide automatic alternate
routing (Planned Redundancy)
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6. Where is the information stored?
Distributed databases either:
Divide a database and distribute its portions throughout a
system without duplicating the data.
Users do not need to know where a piece of data is located
to access it, because the system knows where all the data is
stored.
Store the same data at several different locations, with one
site containing the master file
Issue: synchronization of data is a significant problem.
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7. What rules or standards are used?
System wide rules mean that an operating discipline for
the distributed system has been developed and is
enforced at all times.
These rules govern communication between nodes,
security, data accessibility, program and file transfers,
and common operating procedures.
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8. Two Guiding Frameworks
1. An Organizational Framework
A driving force behind distributed processing is to give
people more control over their work. This autonomy can
happen at any of seven levels:
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10. Business ecosystem or value chain (inter-enterprise)
Enterprise
Country or region
Site (plants, warehouses, branch offices)
Department or process
Work group or team
Individuals
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11. Locate processing power and DB at each level in the
organization
Top level deals with organizations that work closely together
as buyer-seller, partner etc.
Next three levels (Enterprise, Region and Site) are traditional
domain of IS, where computers resided in the past.
Bottom three levels (Department, Team and Individual) are
where the bulk of employees.
Intent: give autonomy and decision-making power to better
serve customers.
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12. 2. A Technical Framework
Migration of computer power to end users will be driving
force for network-based information system. SUMURU -
single user, multiple user, remote utility.
1. Processors:
SU: single user, stand-alone and connected to LNs;
clients
MU: multiple user, serve local groups of users; server.
Also heavy duty computation for SUs, backups for MUs,
program libraries for SUs, and database management.
RU: remote utility, heavy-duty computing, corporate DB
management, corporation mainframes and value-added
network services
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13. 2. Networks:
LN: local networks, high-speed information transfer, LAN.
RN: remote networks, lower transfer speeds, WAN, MAN, Internet.
3. Services that this network architecture provides:
access
file transfer
e-mail
4. Standards needed in three areas:
OS
communication protocols: TCP/IP
DBMS: SQL
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15. 3.3. Managing Telecommunications
Telecommunications is the flow of information among individuals, work groups,
departments, customer sites, regional offices, between enterprises, and with the
outside world.
The Internet has also opened up a “cyberspace” where people can be in a virtual
world, where organizations can conduct business, and in fact, a place where
organizational processes exist.
This is providing the foundation for the e-business economy, as just about
everything about telecom is shifting.
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16. Telecommunications = electronically sending data in any form from one place to
another between
People
Machines, or
Objects
Generally, Information System departments have been responsible for
designing, building, and maintaining the information highway in the same way
that governments are responsible for building and maintaining streets, roads,
and freeways.
Once built, the network, with its nodes and links, provides infrastructure for the
flow of information and messages.
Telecom is the basis for the way people and companies work today.
It provides the infrastructure for moving information and messages.
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17. The Evolving Telecommunications Scene
Even with the recent ‘downturn’ in some countries – the changes in Telecom
are coming fast and furiously. Here are some major changes taking place:
A New Telecommunications Infrastructure is being built:
The oldest part of the telecommunications infrastructure is the telephone
network.
This global network was built on twisted-pair copper wires and was intended for
voice communications.
It uses analog technology, which although appropriate for delivering high-quality
voice, is inefficient for data transmission.
Dedicated circuit (switching).
The basic traffic-handling mechanism had to change for data.
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18. Today, the new telecommunications infrastructure is being built
around the world aimed at transmitting data, and consists of:
Wired - fiber optic links.
Wireless – radio signals.
Both use packet switching, where messages are divided into packets,
each with an address header, and each packet is sent separately.
No circuit is created; each packet may take a different path through the
network.
Packets from any number of senders and of any type, whether e-
mails, music downloads, voice conversations, or video clips, can be
intermixed on a network segment.
Making these next generation networks able to handle much more traffic and a
great variety of traffic.
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19. This architecture allows new kinds of services to be
deployed much more rapidly.
The Internet can handle all kinds of intelligent user
devices, including:
Voice-over-IP (VoIP) phones
Personal digital assistants (PDAs)
Gaming consoles, and
All manner of wireless devices
The global telecom infrastructure is changing from a focus
on voice to a focus on data
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20. 3.4. Managing Information Resources
Managing information resources initially meant managing data, first in
files, then in corporate databases. Next = expanded to include
“information” (data with meaning).
Information in the form of documents (electronic or paper) and Web
content has exploded the size of databases organizations now manage.
Knowledge management is becoming a key to exploiting “intellectual
assets”.
Information resources need to be well managed as information
becomes an important strategic resource.
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21. Managing Data
Database management systems are the main tool for managing
computerized corporate data. They have been around since the
1960s and are based on two major principles:
A three- level conceptual model and
Several alternative ‘data models’ for organizing the data
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22. The Three-Level Database Model
Level 1 - The external, conceptual, or local level,
containing the various “user views” of the corporate
data that each application program uses.
Level 2 - The logical or “enterprise data” level:
‘Technical’ (human) view of the database = under
control of the DBAs
Level 3 - The physical or storage level, specifying the way
the data is physically stored. End user not concerned
with all these ‘pointers and flags’ (how the data is
physically organized).
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23. Managing Data: Four Data Models
The second major concept in database management is alternate ways
to define relationships among data.
Hierarchical model: structures data so that each element is
subordinate to another in a strict hierarchical manner Parent, child
etc.
Network model: allows each data item to have more than one parent,
relationships stated by pointers stored with the data
Relational model: where the data is stored in tables. Eight relational
operations can be performed on this data. Select, Project, Join,
Product, Intersection, Difference, Union, Division e.g. Microsoft Access
Object model: can be used to store any type of data
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24. Managing Information
Once enterprises get their data into shape, that data can
more easily be turned into information.
“Information is power.” “We are in the Information Age.”
These and similar statements would lead you to believe
that managing information is a key corporate activity.
Technology = infrastructure; asset = information that
runs on that infrastructure.
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25. Four Types of Information
Internal record-based information, such as those found
in databases
Internal document-based information, such as reports,
opinions, e-mails and proposals. Pertains to concepts:
ideas, thoughts, etc.
External/record-based information, such as acquisition
from external databases.
External/document-based: WWW
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26. Managing Information: Data Warehouses
Data warehouse: Houses data used to make decisions. This data is
obtained periodically from transaction databases.
The warehouse provides a snapshot of a situation at a specific
time.
Data warehouses differ from operational databases in that they
do not house data used to process daily transactions.
The most common data warehoused are customer data, used to
discover how to more effectively market to current customers as
well as non-customers with the same characteristics.
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27. Key Concepts of Data Warehouse
Metadata: is the part of the warehouse that defines the data.
Metadata means “data about data.” it explains the meaning of each
data element, how each element relates to each other, etc.
Quality data: is the cleaning process to adhere to metadata
standards.
Data marts: is a subset of data pulled off the warehouse for a
specific group of users.
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28. Managing Information: Document Management
Even in today’s Internet-rich world, paper still plays a major role in
most enterprises.
There is also a need to move seamlessly between digital and printed
versions of documents; hence, the importance of document
management.
The field of electronic document management (EDM) uses new
technologies to manage information resources that do not fit easily
into traditional databases.
EDM addresses organizing and managing conceptual, descriptive, and
ambiguous multimedia content.
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29. It is hard to think of anything more pervasive and fundamental to an
organization than documents.
The impact of applying emerging technologies to document management is
potentially significant.
Numerous EDM applications generate value. The ‘Big 3’ are:
To improve the publishing process
To support organizational processes
To support communications among people and groups
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30. Managing Information: Content Management
A major reason content has become important to CIOs (chief
Information Officers) is because it is a core management discipline
underlying online business.
Without production-level Web content, management processes, and
technologies, large-scale e-business is not possible.
Use of XML moves Web content from being in a human-only readable
format to being in a computer-readable format.
Thus, the content can be passed to back-end transaction processing
systems and cause an action to take place.
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31. To create a content management strategy, companies need to
understand the three phases of the content management life cycle:
Managing Content Creation and Acquisition
Content Administration and Safeguarding
Content Deployment and Presentation
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32. 3.5. Managing operations
Due to mergers, the Internet, e-commerce, and the terrorist
attacks, the subject of computer operations has been receiving a
lot of attention.
Systems operations are important because, if they are not
professionally run a company could suffer a computer or network
crash that could shut down their business for some period of
time.
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33. Solving Operational Problems
Operational problems are obvious to the entire company:
response times are slow, networks are down, data isn’t available
and data is wrong.
Three strategies to improve operations:
Buy more equipment
Continuously fight fires and rearrange priorities, getting people to
solve the problems at hand.
Continually document and measure what you are doing, to find out
the real problems, not just the apparent ones. Then set standards
and manage to them = the preferred solution.
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34. Operational Measures
External: What the customer sees: system uptime,
response time, turnaround time, program failures and
customer satisfaction.
Internal: Of interest to systems people: computer usage
as % of capacity, disk storage used, job queue length etc.
Problems reported by external measures can be
explained by deviations in internal measures.
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35. Information Security
Need to understand Internet-based threats and
countermeasures and continuously fund security work to
protect their businesses.
Since 1996 the Computer Security Institute have
conducted an annual survey of US security managers.
Spring 2004 survey report – 2 key findings:
The unauthorized use of computers is declining
The most expensive cybercrime was denial of service
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36. Information Security: The Threats
Threats are numerous
Websites are particularly vulnerable
Political activism is one motivation for Website defacement
Theft of proprietary information is a major concern
Financial fraud is still a significant threat
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37. Information Security: Security’s Five
Pillars
Authentication: verifying the authenticity of users
Identification: identifying users to grant them appropriate access
Privacy: protecting information from being seen
Integrity: keeping information in its original form
Nonrepudiation: preventing parties from denying actions they
have taken
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38. Information Security: Management
Countermeasures
The major problem these days: enterprises cannot have both access to
information and airtight security at the same time. Companies must
make tradeoffs between: absolute information security and the
efficient flow of information. Five major findings from the Computer
Crime Survey:
Most organizations evaluate the return on their security expenditures
Over 80% conduct security audits
The percentage reporting cybercrimes to law enforcement declined
Most do not outsource cybersecurity
Most respondents view security awareness training as important
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39. Information Security: Technical Countermeasures
The trend in computer security is toward defining security policies and
then centrally managing and enforcing those policies via security
products and services or policy-based management.
E.g. a user authenticates to a network once, and then a “rights based system”
gives that user access only to the systems to which the user has been given
rights.
Three techniques used by companies to protect themselves
1. Firewalls: Control access between networks. Used to separate
intranets and extranets from the Internet so that only employees and
authorized business partners can access implementation:
Packet filtering to block “illegal” traffic, which is defined by the security policy…
or
By using a proxy server, which acts as an intermediary
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40. 2. Encryption: to protect against sniffing, messages can be
encrypted before being sent e.g. over the Internet. Two
classes of encryption methods are used today:
Secret Key encryption
Public Key encryption
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41. 3. Virtual Private Networks (VPN): maintains data security
as it is transmitted by using:
Tunneling: creates a temporary connection between a
remote computer and the Internet Service Provider’s local
data center. Blocks access to anyone trying to intercept
messages sent over that link.
Encryption: scrambles the message before it is sent and
decodes it at the receiving end
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42. Three ways to use VPNs:
Remote Access VPNs: give remote employees a way to access an
enterprise intranet by dialing a specific ISP
Remote Office VPNs: give enterprises a way to create a secure
private network with remote offices. The ISP’s VPN equipment
encrypts all transactions
Extranet VPNs: give enterprises a way to conduct e-business with
trading partners
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