Access to Higher Education Computing: Unit 8 Computer Networks Report

This report provides a comprehensive overview of computer networks, encompassing various network types such as LAN, MAN, WAN, PAN, CAN, and GAN, and explores different network architectures including client/server and peer-to-peer models. It delves into network topologies like bus, star, mesh, ring, tree, and hybrid topologies, and discusses network access methods such as CSMA/CD and CSMA/CA. The report further examines the layers of communication, including the OSI and TCP/IP models, and highlights key network protocols and standards like TCP, UDP, IP, FTP, SMTP, HTTP, and various IEEE standards (802.11, 802.5, 802.3). The report also provides visual aids like tables and figures to compare and contrast different network types, topologies, and protocols, offering advantages and disadvantages of different network designs, making it a valuable resource for understanding the complexities of computer networks.

Access to Higher Education Diploma
Assignment Brief
Access to HE Diploma (Computing)
Student Name Submission deadline date
Course/
Subject Title
Access to HE - Assignment 1
Computing
Submission date
Unit Title/Code Unit 8 - Computer Networks
Tutor Name Resubmission deadline date
Date set Resubmission date
This is all my own work and all sources have been acknowledged and attributed.
Student signature:
Learning Outcomes:
At the end of this unit, the
learner will know/be able
to:
Assessment criteria:
The learning outcomes will have been achieved
when the learner has:
First
Sub-
mission
Re-sub-
mission
Achieved
1. 1. identify and describe
types of computer network
and network protocols
1.1 described different types of computer
network in terms of scale eg
WAN/LAN/PAN, network topologies, and
network access methods
1.2 explained the importance of network
protocols and standards and of
established network models eg OSI 7-
layer model and TCP/IP
1.3 described specific network protocols and
standards eg TCP/IP, UDP, 802.2, 802.3,
802.5, FDDI, 802.11, Bluetooth, 3G/4G
and stated the relationship between them
and the different types of network
identified in 1.1

The Bournemouth and Poole College
Access to Higher Education – Computing
Unit 8: Computer Networks
Assignment 1
Heba Haskale
Submitted on: 22/04/21
Word Count: 1000
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Content
1.0 Introduction...............................................................................................................................5
2.0 Networks...................................................................................................................................5
2.1 LAN (Local Area Network)......................................................................................................5
2.2 MAN (Metropolitan area networks)......................................................................................5
2.3 WAN (Wide Area Network)....................................................................................................5
2.4 PAN (Pearson Area Network).................................................................................................6
2.5 CAN (Campus Area Network).................................................................................................6
2.6 GAN (Global Area Networks).................................................................................................6
3.0 Network Architecture................................................................................................................6
3.1 Client/Server network:...........................................................................................................6
3.2 Peer-to-peer:.........................................................................................................................7
4.0 Network topologies...................................................................................................................8
4.1 Bus Topology:........................................................................................................................8
4.2 Star Topology:........................................................................................................................8
4.3 Mesh Topology:.....................................................................................................................9
4.4 Ring Topology:.......................................................................................................................9
4.5 Tree Topology:.....................................................................................................................10
4.6 Hybrid Topology:..................................................................................................................10
5.0 Network Access Methods........................................................................................................11
5.1 CSMA/CD (Carrier Sense Multiple Access with Collision Detection):...................................11
5.2 CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance):..................................11
5.3 Media Access Control Address (MAC Address):...................................................................12
6.0 Layers of Communication........................................................................................................12
 At sender Side:.........................................................................................................................12
 At receiver Side:.......................................................................................................................12
6.1 OSI model:...........................................................................................................................13
7.2 Internet Model (TCP/IP):......................................................................................................14
7.0 Network Protocols and Standards...........................................................................................14
7.1 UDP:.....................................................................................................................................15
7.2 TCP:......................................................................................................................................15
7.3 IP:.........................................................................................................................................15
7.4 FTP:......................................................................................................................................15
7.5 SMTP: S................................................................................................................................15
7.6 HTTP:...................................................................................................................................15
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7.7 Ethernet:..............................................................................................................................15
7.0.1 IEEE 802.11: WIRELESS LAN:............................................................................................16
7.0.2 IEEE 802.5 Token Ring:.....................................................................................................16
7.0.3 802.15 (WPAN):...............................................................................................................16
7.0.4 FDDI.................................................................................................................................16
7.0.5 IEEE 802.3:.......................................................................................................................17
7.0.6 WiFi technology:..............................................................................................................17
7.0.7 Bluetooth.........................................................................................................................18
7.0.8 Cellular Connections:.......................................................................................................18
8.0 Conclusion...............................................................................................................................19
Bibliography.........................................................................................................................................19
Appendices..........................................................................................................................................20
Appendix A – comparing different network types...........................................................................20
Appendix B – Physical topology types.............................................................................................21
Appendix C – Advantages and disadvantages of topologies............................................................21
Appendix D – The Seven Layers of the OSI Model...........................................................................22
Appendix E – The Differences between Client/Server and Peer-to-Peer.........................................23
Table of Figures
Figure 1: example of Bus topology.........................................................................................8
Figure 2: example of Star topology………………………………………………………………....8
Figure 3: example of Mesh topology………………………………………………………………..9
Figure 4: example of Ring topology………………………………………………………………...9
Figure 5: example of Tree topology……………………………………………………………….10
Figure 6: example of Hybrid topology (Star - Bus) ………………………………………..…….10
Figure 6: example of Hybrid topology (Star -Ring) ………………………………………..…….11
Figure 8: TCP/IP VS OSI Model…………………………………………………………...………13
Figure 9: Wi-Fi…………………………………………………………….……………………..
…..17
Figure 10: Bluetooth…………………………………………………….…………………………..18
Figure 11: Cellular connection 4G/ LTD………………………….……………………………….19
Table of Tables
Table 1: advantages and disadvantages of Client/ Server network........................................7
Table 2: advantages and disadvantages of Peer to Peer network..........................................7
Table 3: the layers of OSI model VS TCP/IP model……………………………………….
…….14
Table 4: the protocols and devices of OSI model……………………………………………..…15
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1.0 Introduction
In this report, I will include the basic components which make up a network
and the different types of computer networks. Also, I will Identify and evaluate
different kinds of network topology and access methods.
Moreover, I will explain the network layers of communications and protocols.
2.0 Networks
As (Hosch, W., 2011), computer network is a group of two or more computers
connected with each other for sharing resources and information. A simple
computer network can be built only from two computers while a complex
computer network can be built from several thousand computers.
A computer network can be categorized based on geographical location and
characteristic. Based on geographical location, according to (McCauley, G.,
2019) these categories include:
2.1 LAN (Local Area Network)
A LAN is a computer network which spans over a small geographical area
such as home, building, office, etc. In LAN, computers are placed relatively
close. Since computers are located within small distance, they do not need
special devices and cables to connect with each other.
2.2 MAN (Metropolitan area networks)
A MAN is a computer network which connects two or more LAN networks
within same city. When due to distance connecting two LANs is not possible,
MAN network is used.
It is larger than LAN but smaller than WAN. It deploys special devices and
cables to connect the LANs.
2.3 WAN (Wide Area Network)
WAN is a computer network which spans over a large geographical area such
as state, region, country etc. WANs are typically used to connect two or more
LANs or MANs which are located relatively very far from each other. To
provide connectivity, this network uses special devices, cables and
technologies.
Above categorization (LAN, MAN and WAN) of computer network is purely
based on geographical location. It has nothing to do with the number of
computers in each network. For example, if one computer is located in Poole
and other computer is located in London, connecting these two computers is
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the example of WAN networking. Just like this, if a company starts a new
branch office with 500 computers and all these computers are installed within
a building, this network will be considered as a LAN network. See Appendix
A, which includes comparing between networks.
There are three more types of computer network based on geographical
location but they are rarely used to define the network.
2.4 PAN (Pearson Area Network)
Same as LAN network, but it is limited to a specific person or location such as
home network. This network is usually setup for sharing resources such as
internet and printer within personal computers.
2.5 CAN (Campus Area Network)
Same as MAN network, but it is limited to a university or an academy. This
network is usually setup for educational activities such as classroom updates,
practices labs, emails, exams, notifications, polls, etc.
2.6 GAN (Global Area Networks)
Same as WAN network, but it covers unlimited geographical area. GAN is a
computer network which connects two or more WANs. This network is
increasingly gaining popularity as many companies are expending their
working area beyond their native countries. For example, a company has an
office in Poole and another one Damascus, connecting these two offices will
be considered as a GAN network.
3.0 Network Architecture
According to (Networking, C., 2019), Network architecture is the overall
design of a computer network that describes how a computer network is
configured and what strategies are being used. It mainly focuses on the
function of the networks. It is also known as network model or network design.
Appendix E explains The Differences between the network architecture.
There are two main network architecture:
3.1 Client/Server network: one computer act as a server. Client/Server
that provides services and the other computers (client) on the network
request services from the server.
 In client-server network relationships, certain computers act as server
and other act as clients.
 Local area network (LAN) is based on client server network
relationship.
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 A client-server network is one which all available network resources
such as files, directories, applications and shared devices, are centrally
managed and hosted and then are accessed by client.
 Client server network are defined by the presence of servers on a
network that provide security and administration of the network.
Advantages Disadvantages
 Very secure
 Better performance
 Centralized backup
 very reliable
 requires professional
administration
 More hardware- intensive
 More software intensive
 Expensive dedicated
software
Table 1: advantages and disadvantages of Client/ Server network (Terms, T., 2021)
3.2 Peer-to-peer: is a simple, inexpensive network that Peer-to-Peer
typically connects fewer than 10 computers.
 In peer to peer network each computer is responsible for making its
own resources available to other computers on the network.
 Each computer is responsible for setting up and maintaining its own
security for these resources.
 Each computer is responsible for accessing the required network
resources from peer to peer relationships.
 Peer to peer network is useful for a small network containing less than
10 computers on a single LAN.
 Each computer can function as both client and server.
 Do not have a central control system. There are no servers in peer
networks.
Advantages Disadvantages
 Use less expensive
computer hardware
 Easy to administer
 No NOS required
 More built in
redundancy
 Easy setup & low
cost
 Not very secure
 No central point of storage
or file archiving
 Additional load on
computer because of
resource sharing
 Hard to maintain version
control
Table 1: advantages and disadvantages of Peer to peer network (Terms, T., 2021)
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4.0 Network topologies
As (Studytonight.com. 2021), The way networks are arranged is called a
network topology. Networks can be a single topology or a mixture of more
than one. Whatever the topology, each computer has to have a network
address so that the data knows where it is being sent. Computers break down
data into small parts so they can find the quickest route to their destination.
Appendix B includes topology types. Also, Appendix C contains the
advantages and disadvantages of topologies. The various network topologies
are:
4.1 Bus Topology:
Bus topology is a network type in which every computer and network device is
connected to a single cable. It transmits the data from one end to another in a
single direction. No bi-directional feature is in bus topology. It is a multi-point
connection and a non-robust topology because if the backbone fails the
topology crashes.
Figure 1: example of Bus topology
4.2 Star Topology:
In star topology, all the devices are connected to a single hub through a cable.
This hub is the central node and all other nodes are connected to the central
node.
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Figure 2: example of Star topology
4.3 Mesh Topology:
In a mesh topology, every device is connected to another device via the
particular channel. These channels are known as links. no central connecting
device is needed.
Figure 3: example of Mesh topology
4.4 Ring Topology:
It forms a ring connecting devices with its exactly two neighbouring devices.
A number of repeaters are used for Ring topology with a large number of
nodes, because if someone wants to send some data to the last node in the
ring topology with 100 nodes, then the data will have to pass through 99
nodes to reach the 100th node. The transmission is unidirectional, but it can
be made bidirectional by having 2 connections between each Network Node.
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Figure 4: example of Ring topology
4.5 Tree Topology:
This topology is the variation of Star topology. This topology has a hierarchical
flow of data.
Figure 5: example of Tree topology
4.6 Hybrid Topology:
Hybrid topology is a type of network topology, which is made of two or more
different topologies. Hybrid topologies are often made using combination of
bus topology, star topology, mesh topology (full-mesh topology or partial-
mesh topology), ring topology or wireless topology as per the requirement of
the organization. An example of hybrid topology is star-bus topology.
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Figure 6: example of Hybrid topology (Star - Bus)
Another example of hybrid topology is star-ring topology.
Figure 7: example of Hybrid topology (Star - Ring)
5.0 Network Access Methods
Network Access methods basically define rules on how hosts can place data
on the network. Basically, as (Softwaretestinghelp.com. 2021) it defines a
procedure that determines, how a system places data on the network.
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CSMA/CD, CSMA/CA are commonly in use today:
5.1 CSMA/CD (Carrier Sense Multiple Access with Collision
Detection):
CSMA/CD is one of the most popular access methods in use today. In this
method, a host has free access to the wire and can place data, whenever the
wire is free from traffic.
Whenever a host wishes to place data on the wire, it will first Sense and see if
there is already a signal on the wire. If there is, then the host will wait to send
the data. If not, then the hosts send the data onto the wire.
When two pieces of data are sent onto the wire at the same time, they will
collide and the data will be destroyed. The data will have to be re-transmitted
in such a case. After such a collision, every host will wait for a considerable
time before sending the data again, as it wants to avoid collision.
5.2 CSMA/CA (Carrier Sense Multiple Access with Collision
Avoidance):
CSMA/CA is not as popular as the CSMA/CD. In this method, before a host
sends data onto the wire, it will sense the wire to see if it is free from any
signals. If the wire is free, then the host sends a piece of dummy data onto the
wire to see if it collides with any other data.
If the dummy data does not collide, then the sender host assumes that the
actual data will also not collide, and passes it on to the wire for transmission.
5.3 Media Access Control Address (MAC Address):
MAC addresses are unique identifiers hardwired by the manufacturer of any
NIC or device with an NIC.
Each address is comprised of a total of 6 bytes (48 bits).
The first three bytes are unique to the manufacturer of the device while the
following three bytes are a specific serial number assigned by the
manufacturer.
6.0 Layers of Communication
The main purpose of having several layers in a computer network model is to
divide a process of sending and receiving data into small tasks.
Regarding to (Plixer. 2021.), These layers are connected with each other,
each layer provides certain data to its immediate higher and immediate lower
layer and receives certain data from the same.
Dividing a model layers makes the structure quite simple that makes it easy to
identify the issue if it occurs.
There are three main components of a computer network model: Sender,
receiver and carrier.
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