Build internet infrastructure LO1

MARY HELP COLLEGE
HARD WARE AND NETWORK SERVICING
LEVEL -IV
Unit of Competence
Build Internet Infrastructure
Equipped by Abenezer A.

LO1: Plan and Design Internet Infrastructure
Unit Description
 This unit defines the competence required to design and
implement an infrastructure for internet services
Learning Outcome
LO1:- Plan and design internet infrastructure
LO2:- Install and configure internet infrastructure and services
LO3:- Test security and internet access
LO4:- Ensure user accounts are verified for security
LO5:- Manage and support internet

What is Internet?
 the Internet can be defined as the wired or wireless mode of
communication (Modes of data transmission) through which one can
receive, transmit information that can be used for single or
multiple operations.
 No one owns Internet, although several organizations the
world over work together in its functioning and development.

The functions of the Internet may be divided into several categories
 A Source of Information
 Internet services such as Newsgroups and the World Wide Web (WWW) hold vast
amounts of information, much of which is freely accessible and available 24 hours
per day.
 A Means of Communicating
 Internet services such as Newsgroups and E-mail provide the Internet
communications services.
 A Means of E-Commerce
 A Medium Through Which to Conduct Business

Internet Services
The information services provided by the Internet are as follows:
 E-mail Services
 Website and Web pages Services
 Chat and video conferencing
 News groups
 File Transfer Protocol (FTP)
 Databases for Information storage and retrieval (including search engines)
 Electronic commerce and inventory systems

What is Internet Infrastructure?
 Generally speaking, infrastructures are the frameworks or architectures that
systems are made of.
 For example, a nation's transportation infrastructure consists of roadways,
railroads, airports, ocean ports, and rivers.
 The Internet also has an infrastructure consisting of many different elements,
each of which plays a critical role in the delivery of information from one
point to another.
 The internet infrastructure is an array of hardware and software working to
send and receive information to various systems.

 Internet infrastructure is a collective term for all hardware and
software systems that constitute essential components in the
operation of the Internet.
 Physical transmission lines of all types, such as wired, fiber optic
and microwave links, along with routing equipment, the
accompanying critical software services like the Domain Name
System (DNS), Email, website hosting, authentication and
authorization, storage systems, and database servers are
considered critical Internet components

 Component of Internet Infrastructure
 Data Centre
 Network
 Computer Equipment
 Storage Services
 Server Applications

Data Centre
 A Data Centre is basically a specialist building that has the
ability to power (and cool) huge amounts of computer equipment.
 Typically a Data Centre would also have a very large amount of
network bandwidth to accommodate data transfer in and out of it.
 It generally includes redundant or backup power supplies,
redundant data communications connections, environmental
controls (e.g., air conditioning, fire extinguisher) and security
devices

Network
 Most important foundation block of Internet
Infrastructure is the Network. Without a network
connection no data can pass between Data Centers,
over the Internet, and ultimately onto your Desktop or
Laptop.

Computer Equipment
 Computer equipment refers to any or all of the many
different parts of a computer, as well as peripheral
devices such as printers, external hard drives and
servers.
 Basically, anything relating to a computer is considered
computer equipment.

Storage Services
 Data Storage is a huge part of Internet Infrastructure.
All those emails accessible online, all the web pages on
your favorite web site, all those photos on Facebook …
are all stored on a hard drive in a DC somewhere.
 The basic level of storage is on-server storage, which
means the hard drives in the computer server.

Server Applications
 The final piece of essential Internet Infrastructure is the
server applications themselves. In order for an web
application to be delivered from a server, that server
requires an Operation System (typically Windows or
Linux), a Web Server application (like Apache or
Microsoft IIS), and a Database (such as MySQL, MS-SQL
or Oracle).

Other Elements of Internet Infrastructure
 Telephone lines and fiber optic cables
 These cables connect millions of individual users
and businesses to other parties, transmitting data
at varying speeds, depending on the types of
cabling used.

Transmission Media
 Transmission media is a means by which a
communication signal is carried from one
system to another.
 A transmission medium can be defined as
anything that can carry information from
a source to a destination.
15
Other Elements of Internet Infrastructure

Transmission Media cont’d
 The transmission medium is usually free space,
metallic cable or fiber optic cable.
16

Transmission Media cont’
17

Transmission Media cont’d
18

A. Guided Media
 Guided Transmission media uses a cabling system that
guides the data signals along a specific path.
 Guided media also known as Bounded media, which
are those that provide a conduit from one device to
another, include twisted-pair cable, coaxial cable, and
fiber-optic cable.
19

Note:
 Twisted-pair cable, coaxial cable transport signals in
the form of electric signals and fiber-optic cable
transport signals in the form of light.
20

Cable type
 There are three primary types of cable used to build
LANs:
1. Coaxial
2. Twisted – pair
3. Fiber optic
21

Cable type cont’d
 Coaxial and twisted – pair cables are copper –
based and carry electrical signals, and fiber optic
cables use glass or plastic fibers to carry light
signals.
22

1. Coaxial cable
 It contains two conductors within the sheath.
 At the center of the cable is the copper core that
actually carries the electrical signals.
 The core can be solid copper or braided strands of
copper.
23

1. Coaxial cable cont’d
 Surrounding the core is a layer of insulation, and
surrounding that is the second conductor, which is
typically made of braided copper mesh.
 The second conductor functions as the cable’s ground.
 Finally, the entire assembly is encased in an insulating
sheath made of PVC or Teflon.
24

 There are two types of coaxial cable that have been
used in local area networking:
1. RG 8 also known as thick Ethernet
2. RG – 58 which is known as thin Ethernet
25

 These two cables are similar in construction but differ
primarily in thickness (0.405 inches for RG – 8 versus
0.195 inches for RG – 58) and in the types of connectors
they use (AUI connectors for RG – 8 and bayonet – Neill
– Concelman [BNC] connectors for RG – 58).
26

 Both cable types are wired using the bus topology.
27

Note:
 Thick Ethernet and thin Ethernet are also known
as 10Base5 and 10Base2, respectively.
 These abbreviations indicate that the networks on
which they are used run at 10 Mbps, use
baseband transmissions, and are limited to
maximum cable length of 500 and 200
(actually 185) meters, respectively.
28

 Coaxial cable is used today for many applications,
most noticeably cable television networks.
 It has fallen out of favor as a LAN medium due to
the bus topology’s fault – tolerance problems and
the size and relative inflexibility of the cables,
which make them difficult to install and maintain
29

2. Twisted pair cable
 Twisted pair cable wired in a star
topology is the most common type of
network medium used in LANs today.
 Most new LANs use UTP cable, but there
is also a shielded twisted pair cable (STP)
variety for use in environments more
level to electromagnetic interference.
30

2. Twisted pair cable cont’d
 Unshielded twisted pair cable contains
eight separate copper conductors, as
opposed to the two used in coaxial cable.
 Each conductor is a separate insulated
wire, and the eight wires are arranged in
four pairs, twisted at different rates.
31

 The twists prevent the signals on the
different wire pairs from interfering with
each other (called crosstalk) and also
provides resistance to outside interference.
 The four wire pairs are then covered in a
single sheath,.
32

 The connectors used for twisted pair cables are
called RJ – 45; they are the same as the RJ 11
connectors used on standard telephone cables,
except that they have eight electrical contacts
instead of four.
33

 Twisted pair cable has replaced coaxial
cable in the data networking world
because it has several distinct advantages.
 First, because it contains eight separate
wires, the cable is more flexible than the
more solidly constructed coaxial cable.
34

UTP cable grades
 Unshielded twisted pair cable comes in a
variety of different grades, called
categories by the Electronics Industry
Association (EIA) and the
Telecommunications Industry Association
(TIA), The Combination Being Referred To
As EIA/TIA.
35

UTP cable grades cont’d
1 Voice – grade telephone networks only; not for data
transmissions
2 Voice – grade telephone networks, as well as IBM dumb –
terminal connections to mainframe computers
3 Voice – grade telephone networks, 100 Base – T4, 10 Mbps
Ethernet, 4 Mbps Token Ring.
4 16Mbps Token Ring networks
5 100Base – TX Fast Ethernet.
5e 1000Base – T (Gigabit Ethernet) networks.
36

STP Cable Grades
 STP is similar in construction to UTP, except that it
has only two pairs of wires and it also has
additional mesh shielding around each pair.
 The additional shielding in STP cable makes it
preferable to UTP in installations where
electromagnetic interference is a problem, often due
to the proximity of electrical equipment.
37

STP Cable Grades cont’d
 Token ring STP networks use large, huge connectors
called IBM data connectors (IDCs).
 However, most Token Ring LANs today use UTP cable.
38

3. Fiber optic cable
 Fiber optic cable is a completely different
type of network medium than twisted pair
or coaxial cable.
 Instead of carrying signals over copper
conductors in the form of electrical voltages,
fiber optic cables transmit pulses of light
over a glass or plastic filament.
39

Fiber optic cable cont’d

Note:
 Fiber optic cable is completely resistant
to the electromagnetic interference that
so easily affects copper based cables.
41

 Fiber optic cables are also much less subject
to attenuation – the tendency of a signal to
weaken as it travels over a cable – than
are copper cables.
 On copper cables, signals weaken to the
point of unreadability after 100 to 500
meters.
42

 Some fiber optic cables, but contrast, can span
distances up to 120 kilometers without
excessive signal degradation.
43

 Fiber optic cable is thus the medium of
choice for installations that span long
distances or connect buildings on a campus.
 Fiber optic cable is also inherently more
secure than copper because it is impossible
to tap into a fiber optic link without affecting
normal communication over that link.
44

 A fiber optic cable consists of a clear glass
or clear plastic core that actually carries the
light pulses, surrounded by a reflective layer
called the cladding.
 Surrounding the cladding is a plastic spacer
layer, a protective layer of woven Kevlar
fibers, and an outer sheath.
45

 There are two primary types of fiber optic
cable:
1. Singlemode
2. multimode
46

 With the thickness of the core and the cladding
being the main difference between them.
 The measurements of these two thicknesses are
the primary specifications used to identify each
type of cable.
47

 Singlemode fiber typically has a core
diameter of 8.3 microns, and the thickness
of the core and cladding together is 125
microns.
 This is generally referred to as 8.3/125 Singlemode
fiber.
 Most of the multimode fiber used in data
networking is rated as 62.5/125.
48

 Singlemode fiber is more commonly
found in outdoors installations that span
long distances, such as telephone and
cable television networks.
 This type of cable is les suited to LAN
installations because it is much more
expensive than multimode
49

 Multimode fiber cannot span distances as
long as Singlemode and is much cheaper.
 Fiber optic use one of two connectors, the
straight tip (ST) connector or the subscriber
connector (SC).
50

Self-check
 For each of the following scenarios, specify whether the network will
function properly based on the information given. If not, explain
why.
1. Twenty – five computers are connected to a 300 – meter thin Ethernet
cable segment using a bus topology.
2. Ten computers with 100Base - T4 Fast Ethernet network interface cards
(NICs) are connected to a hub using 100 – meter lengths of Category 3
UTP cable.
3. Networks in two buildings 1000 meters away from each other are
connected together using singlemode fiber optic cable with RJ – 45
connectors.
4. Fifteen computers are connected to a Token Ring network using a physical
ring topology
51

B. Unguided Media
 Unguided media transport data without
using a physical conductor.
 This type of communication is often referred
to as wireless communication.
 It uses wireless electromagnetic signals
to send data.
52

B. Unguided Media cont’d
 Frequencies in the range of about 1 GHz to
40 GHz are referred to as microwave
frequencies.
 At these frequencies, highly directional
rays are possible, and microwave is quite
suitable for point-to-point transmission.
53

 Frequencies in the range of 3 KHz to 1 GHz
are suitable for omnidirectional
applications.
 We refer to this range as the radio range.
54

 Another important frequency range, for
local applications, is the infrared.
 For unguided media, transmission and
reception are achieved by means of an
antenna.
55

Antennas
 An antenna can be defined as an electrical
conductor or system of conductors used either
for radiating electromagnetic energy or for
collecting electromagnetic energy.
56

Antennas cont’d
 For transmission of a signal, radio-frequency
electrical energy from the transmitter is
converted into electromagnetic energy by the
antenna and radiated into the surrounding
environment (atmosphere, water).
57

Antennas cont’d
 For reception of a signal, electromagnetic
energy on the antenna is converted into
radio-frequency electrical energy and fed
into the receiver.
 An antenna will radiate power in all
directions but, typically, does not perform
equally well in all directions.
58

Antennas cont’d
 A common way to characterize the
performance of an antenna is the
radiation pattern.
 An isotropic antenna radiates power in
all directions equally.
59

Categories of Unguided Media
 There are three types of Unguided Media
1. Radio waves
2. Micro waves
3. Infrared
60

1. Radio waves
 Electromagnetic wave ranging in
frequencies between 3 KHz and 1GHz are
normally called radio waves.
 Radio waves are omni-directional when
an antenna transmits radio waves they
are propagated in all directions.
61

1. Radio waves cont’d
 This means that sending and receiving
antenna do not have to be aligned.
 A sending antenna can send waves that can
be received by any receiving antenna.
 Radio waves particularly those waves that
propagate in sky mode, can travel long
distances.
62

1. Radio waves cont’d
 This makes radio waves a good candidate for long-
distance broadcasting.
 Radio waves particularly those of low and medium
frequencies can penetrate walls.
63

2. Microwaves
 Electromagnetic waves having frequencies
between 1 and 300 GHz are called
microwaves.
 Microwaves are unidirectional; when an
antenna transmits microwaves they can be
narrowly focused.
64

2. Microwaves cont’d

 This means that the sending and
receiving antennas need to be aligned.
 A pair of antennas can be aligned
without interfering with another pair of
aligned antennas.
66

 Microwaves propagation is line-of-sight.
 Since the towers with the mounted
antennas needs to be in direct sight of
each other, towers that are far apart need
to be very tall.
67

 The curvature of the earth as well as other
blocking obstacles do not allow two short
towers to communicate using microwaves.
 Repeaters are often needed for long distance
communication.
 Very high frequency microwaves cannot
penetrate walls.
68

 Parabolic dish antenna is used for this
means of transmission
69

3. Infrared
 Infrared signals with frequencies ranges
from 300 GHz to 400 GHz can be used for
short range communication.
 Infrared signals, having high frequencies,
cannot penetrate walls.
 This helps to prevent interference between
one system and another.
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3. Infrared cont’d
 Infrared Transmission in one room
cannot be affected by the infrared
transmission in another room.
 There are number of computer devices
which are used to send the data through
infrared medium e.g. keyboard, mice, and
printers.
71

3. Infrared cont’d
 There are some manufacturers provide a
special part called the IrDA port that allows a
wireless keyboard to communicate with a PC.
72

Types of Internet access
 56K Dial-up
 Uses existing phone lines.
 Lower cost-usually around $22.00 per month.
 Slow -- Can be limited to speeds of 28.8K to 33.6K. Upload
speeds can be limited to as low as 28.8, with download speeds
approaching 56K under only perfect conditions.
 Service can be somewhat unreliable (busy signals,
spontaneously terminated sessions, etc.

 Dial-up internet access
Advantages
 Uses existing phone lines(analog signal).
 Lower cost
Disadvantages
 Slow -- Can be limited to speeds of 28.8K to 33.6K. Upload speeds can be
limited to as low as 28.8, with download speeds approaching 56Kbps
under only perfect conditions.
 Service can be somewhat unreliable (busy signals, spontaneously
terminated sessions, etc).

 Broadband Internet access
What is Broadband?
 The term broadband commonly refers to high-speed Internet access that is always on and faster than the
traditional dial-up access.
How is broadband different from dial-up service?
 Broadband service provides higher-speed of data transmission. It allows more content to be carried
through the transmission ―pipeline.‖
 Broadband provides access to the highest quality Internet services—streaming media, VoIP (Internet
phone), gaming, and interactive services.
 Broadband is always on. It does not block phone lines and there is no need to reconnect to network
after logging off.
 Less delay in transmission of content when using broadband.

Types of Broadband Internet access
Digital Subscriber Line (DSL)
 DSL is an ―always-on‖ technology. This means that you don‘t need
to dial up each time to connect to the Internet. DSL uses the
existing copper telephone lines to provide high-speed digital
data communication between end users and telephone companies.
 DSL is a wire line transmission technology that transmits data
faster over traditional copper telephone lines already installed to
homes and businesses.

 DSL-based broadband provides transmission
speeds ranging from several hundred Kbps to
millions of bits per second (Mbps).
 The availability and speed of your DSL service
may depend on the distance from your home or
business to the closest telephone company facility.

 There are many types of DSL
 ADSL: Asymmetric DSL
 HDSL: High Data Rate DSL
 SDSL: Symmetric DSL
 VDSL: Very High Data Rate DSL
 IDSL: ISDN DSL

The following are types of DSL transmission technologies:
 ADSL (Asymmetric DSL) currently is the most common
implementation. It has speeds that vary from 384 Kbps to more
than 6 Mbps downstream. The upstream speed typically is lower.
 HDSL (High Data Rate DSL) provides equal bandwidth in both
directions. It is 1.544 Mbps in North America and 2.048 Mbps in
Europe.
 SDSL (Symmetric DSL) provides the same speed, up to 3 Mbps,
for uploads and downloads.

 VDSL (Very High Data Rate DSL) is capable of bandwidths
between 13 and 52 Mbps downstream and 16 Mbps upstream.
 IDSL (ISDN DSL) is actually DSL over ISDN lines. It is a set of
CCIT/ITU standards for digital transmission over ordinary
telephone copper wire, as well as over other media, with a top
speed of 144 Kbps. ISDN is available in areas that do not
qualify for other DSL implementations. An ISDN adapter at both
the user side and service provider side is required. ISDN
generally is available in urban areas in the U.S. and Europe
from the local phone company.

Integrated Services Digital Network (ISDN)
 ISDN is another example of broadband. ISDN uses multiple channels
and can carry different types of services; therefore, it is considered a
type of broadband. ISDN can carry voice, video, and data.
 ISDN digital connections offer three services: Basic Rate Interface (BRI),
Primary Rate Interface (PRI), and Broadband ISDN (BISDN).
 ISDN uses two different types of communication channels. The B
channel is used to carry the information—data, voice, or video. The D
channel usually is used for controlling and signaling, but it can be used
for data.

Dialup vs. DSL

Types of ISDN:
 BRI: ISDN Basic Rate Interface offers a dedicated 128-Kbps connection
using two 64-Kbps B channels. ISDN BRI also uses one 16-Kbps D channel
for call setup, control, and teardown.
 PRI:ISDN Primary Rate Interface offers up to 1.544 Mbps over 23 B
channels in North America and Japan or 2.048 Mbps over 30 B channels in
Europe and Australia. ISDN PRI also uses one 64-Kbps D channel for call
maintenance.
 BISDN: Broadband ISDN manages different types of service all at the
same time. BISDN is mostly used only in network backbones.

Cable Modem
 Cable modem service enables cable operators to provide
broadband using the same coaxial cables that deliver pictures
and sound to your TV set.
 Most cable modems are external devices that have two
connections: one to the cable wall outlet, the other to a computer.
They provide transmission speeds of 1.5 Mbps or more.
 Subscribers can access their cable modem service by simply turning
on their computers, without dialing-up an ISP. You can still watch
cable TV while using it.
 Transmission speeds vary depending on the type of cable modem,
cable network, and traffic load. Speeds are comparable to DSL.

Fiber optic Technology
 Fiber optic technology converts electrical signals carrying data to light and
sends the light through transparent glass fibers about the diameter of a human
hair.
 Fiber transmits data at speeds far more than current DSL or cable modem
speeds, typically by tens or even hundreds of Mbps.
 The actual speed you experience will vary depending on a variety of factors,
such as how close to your computer the service provider brings the fiber and how
the service provider configures the service, including the amount of bandwidth
used. The same fiber providing your broadband can also simultaneously deliver
voice (VoIP) and video services.

Wireless
 Wireless broadband connects a home or business to the Internet using a radio link
between the customer‘s location and the service provider‘s facility. Wireless
broadband can be mobile or fixed.
 Wireless technologies using longer-range directional equipment provide
broadband service in remote or sparsely populated areas where DSL or cable
modem service would be costly to provide. Speeds are generally comparable to
DSL and cable modem. An external antenna is usually required.
 Wireless broadband Internet access services offered over fixed networks allow
consumers to access the Internet from a fixed point while stationary and often
require a direct line-of-sight between the wireless transmitter and receiver.
These services have been offered using both licensed range and unlicensed
devices. For example, thousands of small Wireless Internet Services Providers
(WISPs) provide such wireless broadband at speeds of around one Mbps using
unlicensed devices, often in rural areas not served by cable or wire line
broadband networks.

Cont.…
 Wireless Local Area Networks (WLANs) provide wireless
broadband access over shorter distances and are often used to
extend the reach of a "last-mile" wire line or fixed wireless
broadband connection within a home, building, or campus
environment. Wi-Fi networks use unlicensed devices and can be
designed for private access within a home or business, or be used
for public Internet access at "hot spots" such as restaurants, coffee
shops, hotels, airports, convention centers, and city parks.
 Mobile wireless broadband services are also becoming available
from mobile telephone service providers and others. These services
are generally appropriate for highly-mobile customers and require
a special PC card with a built in antenna that plugs into a user‘s
laptop computer. Generally, they provide lower speeds, in the
range of several hundred Kbps

 Satellite
 Just as satellites orbiting the earth provide necessary links for telephone
and television service, they can also provide links for broadband.
Satellite broadband is another form of wireless broadband, and is also
useful for serving remote or sparsely populated areas.
 Downstream and upstream speeds for satellite broadband depend on
several factors, including the provider and service package purchased,
the consumer‘s line of sight to the orbiting satellite, and the weather.
Typically a consumer can expect to receive (download) at a speed of
about 500 Kbps and send (upload) at a speed of about 80 Kbps.
 These speeds may be slower than DSL and cable modem, but they are
about 10 times faster than the download speed with dial-up Internet
access. Service can be disrupted in extreme weather conditions.

Defining Network Infrastructure
 A network Infrastructure can be defined as the grouping of
hardware devices and software components which are
necessary to connect devices within the organization,
and to connect the organization to other organizations
and the Internet.
 Typical hardware components utilized in a networking
environment are network interface cards, computers,
routers, hubs, switches, printers, and cabling and phone
lines.
 Typical software components utilized in a networking
environment are the network services and protocols
needed to enable devices to communicate.
Considerations in Planning a Network Infrastructure

When you plan your network infrastructure, a number of
key elements need to be clarified or determined:
 Determine which physical hardware components are needed
for the network infrastructure which you want to implement.
 Determine the software components needed for the network
infrastructure.
 Determine the following important factors for your hardware
and software components:
 Specific location of these components
 How the components are to be installed.
 How the components are to be configured.

When you implement a network infrastructure, you need
to perform a number of activities that can be broadly
Grouped as follows:
 Determine the hardware and software components needed.
 Purchase, assemble and install the hardware components.
 Install and configure the operating systems, applications and
all other software.

Physical infrastructure of the network
 The physical infrastructure of the network refers to the
physical design of the network together with the hardware
components.
 The physical design of the network is also called the
network’s topology.
 When you plan the physical infrastructure of the network,
you are usually limited in your hardware component
selection by the logical infrastructure of the network.

Logical infrastructure of the network
 The logical infrastructure of the network is made up of all the software
components required to enable connectivity between devices, and to
provide network security.
 The network‘s logical infrastructure consists of the following:
 Software products
 Networking protocols/services.
 It is therefore the network‘s logical infrastructure that makes it possible for
computers to communicate using the routes defined in the physical network
topology.

 The logical components of the network topology
define a number of important elements:
 Speed of the network.
 Type of switching that occurs.
 Media which will be utilized.
 Type of connections which can be formed.

 Planning network infrastructure is a complex task that needs to
be performed so that the network infrastructure needed by the
organization can be designed and created.
 Proper planning is crucial to ensure a highly available network
and high performance network that result in reduced costs and
enhances business procedures for the organization.

 To properly plan your network infrastructure, you have to be
knowledgeable on a number of factors, including the following:
 Requirements of the organization.
 Requirements of users.
 Existing networking technologies.
 Necessary hardware and software components.
 Networking services which should be installed on the user‘s
computers so that they can perform their necessary tasks.

A typical network infrastructure planning strategy should include
the following:
 Determine the requirements of the organization and its users, and
then document these requirements.
 Define a performance baseline for all existing hardware devices.
 Define a baseline for network utilization as well.
 Identify the capacity for the physical network installation. This
should include the following:
 Server hardware, client hardware.
 Allocation of network bandwidth for the necessary networking
services and applications.
 Allocation of Internet bandwidth

 Determine which network protocol will be used.
 Determine which IP addressing method you will use.
 Determine which technologies, such as operating systems and
routing protocols are needed to cater for the organization‘s
needs as well as for possible future expansions.
 Determine the security mechanisms which will be
implemented to secure the network and network
communication.

 After planning, the following step would be to implement the
technologies which you have identified.
 Implementation of the network infrastructure involves the
following tasks:
 Installing the operating systems.
 Installing the necessary protocols and software components.
 Deploying DNS.
 Designing the DNS namespace.
 Assigning IP addresses and subnet masks to computers.
 Deploying the necessary applications.
 Implementing the required security mechanisms.
 Defining and implementing IPSec policies.

 Determining the network infrastructure maintenance strategy
which you will employ once the network infrastructure is
implemented.
 Network infrastructure maintenance consists of the following
activities:
 Upgrading operating systems.
 Upgrading applications.
 Monitoring network performance, processes and usage.
 Troubleshooting networking issues.

Determining Network Protocols
 Transmission Control Protocol/Internet Protocol
(TCP/IP)
 Domain Name Service (DNS),
 Dynamic Host Configuration Protocol (DHCP),
 Windows Internet Name Service (WINS)

Functional requirements specification
 The functional specification describes what the
system will do, as opposed to how it will be done.
 This distinction is important, because: the client may
not be interested in the details of how a function is
implemented, and the technical details may simply
cause confusion for the client the implementation
details may need to change during the design and
development of the project you don‘t want to have to
negotiate changes to

 …….The functional specification just to change
details of implementation the technical specification
for large projects will be detailed in a separate
document, and you should not entangle one with the
other.

Cont….
 The language of the functional specification should be
clear, concise and (as far as possible) non-technical.
 It is very important to attend to details in the functional
specification.
 One absent word may commit a vendor company to
develop extra functionality that was never intended, and
damage the profitability of the project.

Fixed requirements
 Some requirements are fixed, and not derived from the
ideal functionality that the product or system should possess.
These are often in the form of constraints set by the client.
 For example:
 A client may require a particular look-and-feel to their
website.
 The client may require your system to interface to their
existing systems in a particular way.

 Use cases
 A use case is a very useful tool to help you start to determine the
required functionality of a system. Use cases have quickly become a
standard tool for capturing functional requirements.
 A use case is a diagram showing how the proposed system will be
used in one particular scenario, by a particular user. Use cases allow
the designer to focus on details, but keep the design grounded in the
basics of how the system will be used. A large system will have many
use cases.

Functional requirements
 Functional requirements describe the way in which the
different components and functions in the solution will
interact.
 They will clarify how the solution is going to work and how
users can use it.
 Next are some examples of the questions you might ask in
order to determine the functional requirements of an IT
system.

 User requirements
 How many users are expected to use the system?
 How many people will be utilising the solution at one time?
 Where the users will be located (e.g. abroad, interstate or
at home)?
 What navigation model will it use?
 What is the range of the content?
 How much content will it include?
 How will the content be structured?

 Technical requirements
 What types of computers/operating systems will the users
operate?
 Are their desktops all the same?
 What bandwidth restrictions occur presently?
 What security (login) will they need?

Cont.…..
 What backup policies need to be in place?
 Who will have administration rights?
 What will the business do if the system fails at any stage?
 Who is the project sponsor?
 What does management expect the system will do and
won‘t do?

 Hardware
 Compatibility: will the solution work with existing systems?
 Support for multimedia formats: will the existing systems and
architecture support all types of media?
 Will the new system be supported by existing resources within
the company?
 Is there funding available for new hardware? (eg new servers)
 What is the backup strategy? Has this been costed?

Cont.….
 Will there be time delays to purchase and install
hardware?
 Are there other projects that you may be able to share
hardware costs with?
 If the system needs to cater for multimedia, does there
need to be extra attention paid to being able to store
and transmit large graphic, sound and video files?
 If you are a consultant or part time employee, will you
be given permissions and rights to install and support
the system fully? (As some computer centres are secure).

 Software
 What is the true cost of the software?
 Are there licensing issues? (As the system is in development, should you
pay for all the licensing now, or when the system is in live mode?)
 Can the software be licensed for use by multiple users who use it on
different machines? (Concurrent licensing)
 How long has the software been on the market for?
 What happens if the software company becomes insolvent? Who
supports it?
 Who owns the source code?

Cont.….
 What happens if the source code is modified; who supports the
product then?
 Does the solution work with all other company software systems?
 If web-based, does the solution function on all common browsers?
 If security is a concern, can the software be delivered in a ‗locked
down‘ format?
 Does the software support all file formats? (This is especially
important when working on multimedia tasks.)
 Is the software easy to use or are there major training issues/costs?

 Support materials
 You will need to consider the content and design
requirements of all support materials. Support materials
could include:
 system specifications
 user guides
 knowledge banks
 intranet/Internet help sites/CD-ROMs

Cont.….
 Training manuals
 General user documentation and print-based help.
 You will also need to consider workshops, seminars or
briefings you may need to run in order to support the
software/hardware/system.
 During the development of the scope document you will
have determined the kinds of support materials that you will
need. You will probably also establish who will be
responsible for the production of those materials.

Sample Network /Internet Infrastructure Physical and Logical
Design

Sample Network /Internet Infrastructure Physical
and Logical Design
Design

Sample Network /Internet Infrastructure Physical and
Logical Design
Design

Thank for your
attention!!!

Build internet infrastructure LO1

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