COIT20246: Data Communication and Computer Systems - Semester 1 Report

Desklib provides past papers and solved assignments for students. This report explores computer systems and data communication.

COIT20246

Table of Contents
Data storage.............................................................................................................................................5
Why data storage is important.............................................................................................................6
How data storage works.......................................................................................................................6
Types of data storage devices/mediums..............................................................................................6
Network Interoperability.........................................................................................................................7
Types of interoperability......................................................................................................................7
Interoperability and open standards.....................................................................................................7
Open standards.................................................................................................................................8
Post facto interoperability................................................................................................................8
The Boot process.....................................................................................................................................8
Modern boot loaders............................................................................................................................9
First-stage boot loader.....................................................................................................................9
Second-stage boot loader...............................................................................................................10
Network booting............................................................................................................................10
Personal computers (PC)...................................................................................................................10
Boot devices...................................................................................................................................10
Boot sequence....................................................................................................................................11
Other kinds of boot sequences...........................................................................................................11
CPU components...................................................................................................................................11
Types of computer systems................................................................................................................12
Personal computer..........................................................................................................................12
Motherboard...................................................................................................................................12
Expansion cards.................................................................................................................................13
Storage devices..................................................................................................................................13
Fixed media........................................................................................................................................13
Input and output peripherals..............................................................................................................13
Input...............................................................................................................................................14
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Output device.................................................................................................................................14
Mainframe computer......................................................................................................................14
Supercomputer...................................................................................................................................14
Hardware upgrade..............................................................................................................................14
Kernel (operating system)......................................................................................................................14
Functions............................................................................................................................................15
The central processing unit (CPU).................................................................................................15
Input/output (I/O) devices..............................................................................................................15
Resource Management...................................................................................................................15
Memory management....................................................................................................................16
Device management.......................................................................................................................16
System calls...................................................................................................................................17
Network layer........................................................................................................................................17
Relation to TCP/IP model..................................................................................................................18
The 7-Layer OSI model.........................................................................................................................18
Physical Layer........................................................................................................................................18
Data-Link Layer.................................................................................................................................18
Network Layer...................................................................................................................................18
Transport Layer..................................................................................................................................19
Session Layer.....................................................................................................................................19
Presentation Layer.............................................................................................................................19
Application Layer..............................................................................................................................19
Dynamic Host Configuration Protocol (DHCP)....................................................................................19
Dynamic allocation........................................................................................................................20
Automatic allocation......................................................................................................................20
Manual allocation..........................................................................................................................20
Operation...........................................................................................................................................20
DHCP discovery............................................................................................................................21
DHCP offer....................................................................................................................................21
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DHCP request................................................................................................................................21
DHCP acknowledgement...............................................................................................................21
DHCP information.........................................................................................................................21
DHCP releasing.............................................................................................................................21
DHCP options................................................................................................................................22
Reliability...........................................................................................................................................22
Security..............................................................................................................................................22
Quality of service...................................................................................................................................22
Applications.......................................................................................................................................23
Mechanisms.......................................................................................................................................23
Over-provisioning..............................................................................................................................24
IP and Ethernet efforts.......................................................................................................................24
Digital & Binary signalling....................................................................................................................25
Digital electronics..............................................................................................................................25
Signal processing...............................................................................................................................26
Data communications management issues............................................................................................26
Standards issues in data communications..........................................................................................26
Noise or Electrical Distortion............................................................................................................26
Random Bit Errors.............................................................................................................................27
Burst Errors........................................................................................................................................27
Types of Information System................................................................................................................27
Operational management level..........................................................................................................28
Tactical Management Level...............................................................................................................28
Transaction Processing System (TPS)...............................................................................................28
Management Information System (MIS)...........................................................................................29
Decision Support System (DSS)........................................................................................................29
BI tools – types / data analysis / contrasts.............................................................................................29
What are the types of business intelligence software?......................................................................30
Data management..........................................................................................................................30
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Data Discovery..............................................................................................................................30
What are the potential issues with business intelligence software?...................................................31
Relational databases...............................................................................................................................31
Types of databases.............................................................................................................................32
Advantages of relational databases....................................................................................................32
Rapid application development methods – use and differences from standard methods (SDLC)........33
What is SDLC?..................................................................................................................................33
SDLC Models....................................................................................................................................33
Stage 1: Planning and Requirement Analysis................................................................................33
Stage 2: Defining Requirements....................................................................................................34
Stage 3: Designing the Product Architecture.................................................................................34
Stage 4: Building or Developing the Product................................................................................34
Stage 5: Testing the Product..........................................................................................................34
Stage 6: Deployment in the Market and Maintenance...................................................................34
Project management...............................................................................................................................34
Approaches........................................................................................................................................34
Phased approach............................................................................................................................34
Lean project management..................................................................................................................35
Product-based planning......................................................................................................................35
Process groups...................................................................................................................................35
Malware – types of threats & methods of spread..................................................................................36
Types of malware...............................................................................................................................36
How malware works..........................................................................................................................37
Legal, ethical concepts and issues.........................................................................................................37
Five Moral Dimensions of the Information Age...............................................................................37
 Information rights and obligations.........................................................................................37
 Property rights and obligations..............................................................................................38
 Accountability and control.....................................................................................................38
 System quality........................................................................................................................38
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 Quality of life.........................................................................................................................38
Key Technology Trends That Raise Ethical Issues...........................................................................38
Network security – firewalls, cryptographic systems............................................................................39
Types of Security Attacks..................................................................................................................39
Security Services................................................................................................................................40
Network Security Model................................................................................................................41
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Data storage
Data storage is the recording (storing) of information (data) in a storage
medium. DNA and RNA, handwriting, phonographic recording, magnetic tape, and optical
discs are all examples of storage media. Recording is accomplished by virtually any form
of energy. Electronic data storage requires electrical power to store and retrieve data.
Data storage in a digital, machine-readable medium is sometimes called digital
data. Computer data storage is one of the core functions of a general purpose
computer. Electronic documents can be stored in much less space than
paper documents. Barcodes and magnetic ink character recognition (MICR) are two ways of
recording machine-readable data on paper.
Why data storage is important
Underscoring the importance of storage is a steady climb in the generation of new data,
which is attributable to big data and the profusion of internet of things (IoT) devices. Modern
storage systems require enhanced capabilities to allow enterprises to apply machine learning-
enabled artificial intelligence (AI) to capture this data, analyze it and wring maximum value
from it. Larger application scripts and real-time database analytics have contributed to the
advent of highly dense and scalable storage systems, including high-performance computing
storage, converged infrastructure, composable storage systems, hyper-converged
storage infrastructure, scale-out and scale-up network-attached storage (NAS) and object
storage platforms.
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How data storage works
The term storage may refer both to a user's data generally and, more specifically, to the
integrated hardware and software systems used to capture, manage and prioritize the data.
This includes information in applications, databases, data warehouses, archiving, backup
appliances and cloud storage. Digital information is written to target storage media through
the use of software commands. The smallest unit of measure in a computer memory is a bit,
described with a binary value of 0 or 1, according to the level of electrical voltage contained
in a single capacitor. Eight bits make up one byte.
Types of data storage devices/mediums
Data storage media have varying levels of capacity and speed. These include cache memory,
dynamic RAM (DRAM) or main memory; magnetic tape and magnetic disk; optical disc,
such as CDs, DVDs and Blu-ray disks; flash memory and various iterations of in-memory
storage; and cache memory.
The main types of storage media in use today include hard disk drives (HDDs), solid-state
storage, optical storage and tape. Spinning HDDs use platters stacked on top of each other
coated in magnetic media with disk heads that read and write data to the media. HDDs are
widely used storage in personal computers, servers and enterprise storage systems, but SSDs
are starting to reach performance and price parity with disk.
Network Interoperability
Interoperability is a characteristic of a product or system, whose interfaces are completely
understood, to work with other products or systems, at present or in the future, in either
implementation or access, without any restrictions.
While the term was initially defined for information technology or systems
engineering services to allow for information exchange, a broader definition takes into
account social, political, and organizational factors that impact system to system
performance. Task of building coherent services for users when the individual components
are technically different and managed by different organizations
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Types of interoperability
If two or more systems are capable of communicating with each other, they exhibit syntactic
interoperability when using specified data formats and communication
protocols. XML or SQL standards are among the tools of syntactic interoperability. This is
also true for lower-level data formats, such as ensuring alphabetical characters are stored in a
same variationof ASCII or a Unicode format in all the communicating systems.
Beyond the ability of two or more computer systems to exchange information, semantic
interoperability is the ability to automatically interpret the information exchanged
meaningfully and accurately in order to produce useful results as defined by the end users of
both systems. To achieve semantic interoperability, both sides must refer to a common
information exchange reference model. The content of the information exchange requests are
unambiguously defined: what is sent is the same as what is understood. The possibility of
promoting this result by user-driven convergence of disparate interpretations of the same
information has been object of study by research prototypes such as S3DB.
Interoperability and open standards
Interoperability imply exchanges between a range of products, or similar products from
several different vendors, or even between past and future revisions of the same product.
Interoperability may be developed post-facto, as a special measure between two products,
while excluding the rest, by using Open standards.
Open standards
Open standards rely on a broadly consultative and inclusive group including representatives
from vendors, academics and others holding a stake in the development that discusses and
debates the technical and economic merits, demerits and feasibility of a proposed common
protocol. After the doubts and reservations of all members are addressed, the resulting
common document is endorsed as a common standard.
Post facto interoperability
Post facto interoperability may be the result of the absolute market dominance of a particular
product in contravention of any applicable standards, or if any effective standards were not
present at the time of that product's introduction.
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 The data is provided by the original vendor on a discretionary basis, who has every
interest in blocking the effective implementation of competing solutions, and may
subtly alter or change its product, often in newer revisions, so that competitors'
implementations are almost, but not quite completely interoperable, leading customers
to consider them unreliable or of a lower quality.
 The data itself may be encumbered, e.g. by patents or pricing, leading to a dependence
of all competing solutions on the original vendor, and possibly leading a revenue
stream from the competitors' customers back to the original vendor.
 Even when the original vendor is genuinely interested in promoting a healthy
competition, post-facto interoperability may often be undesirable as many defects or
quirks can be directly traced back to the original implementation's technical
limitations.
 Lack of an open standard can also become problematic for the customers, as in case of
the original vendor's inability to fix a certain problem that is an artifact of technical
limitations in the original product.
The Boot process
In computing, booting is starting up a computer or computer appliance until it can be used. It
can be initiated by hardware such as a button press or by software command. After the power
is switched on, the computer is relatively dumb and can read only part of its storage
called read-only memory (ROM). There, a small program is stored called firmware. It
does power-on self-tests and, most importantly, allows accessing other types of memory like
a hard disk and main memory. The firmware loads bigger programs into the computer's main
memory and runs it. In general purpose computers, but additionally in smartphones and
tablets, optionally a boot manager is run.
Restarting a computer also is called reboot, which can be "hard", e.g. after electrical power to
the CPU is switched from off to on, or "soft", where the power is not cut. On some systems, a
soft boot may optionally clear RAM to zero. Both hard and soft booting can be initiated by
hardware such as a button press or by software command.
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Modern boot loaders
When a computer is turned off, its software — including operating systems, application code,
and data — remains stored on non-volatile memory. When the computer is powered on, it
typically does not have an operating system or its loader in random-access memory (RAM).
The computer first executes a relatively small program stored in read-only memory(ROM)
along with a small amount of needed data, to access the nonvolatile device or devices from
which the operating system programs and data can be loaded into RAM.
The small program that starts this sequence is known as a bootstrap loader, bootstrap or boot
loader. This small program's only job is to load other data and programs which are then
executed from RAM. Often, multiple-stage boot loaders are used, during which several
programs of increasing complexity load one after the other in a process of chain loading.
First-stage boot loader
Boot loaders may face peculiar constraints, especially in size; for instance, on the IBM PC
and compatibles, a boot sector should typically work in only 32 KB (later relaxed to 64 KB)
he first stage of PC boot loaders (FSBL, first-stage boot loader) located on fixed
disks and removable drives must fit into the first 446 bytes of the Master Boot Record in
order to leave room for the default 64-byte partition table with four partition entries and the
two-byte boot signature, which the BIOS requires for a proper boot loader — or even less,
when additional features like more than four partition entries (up to 16 with 16 bytes each),
disk signature (6 bytes), a disk timestamp (6 bytes)
Second-stage boot loader
Second-stage boot loaders, such as GNU GRUB, BOOTMGR, Syslinux, NTLDR or BootX,
are not themselves operating systems, but are able to load an operating system properly and
transfer execution to it; the operating system subsequently initializes itself and may load
extra device drivers. The second-stage boot loader does not need drivers for its own
operation, but may instead use generic storage access methods provided by system firmware
such as the BIOS or Open Firmware, though typically with restricted hardware functionality
and lower performance. Large and complex systems may have boot procedures that proceed
in multiple phases until finally the operating system and other programs are loaded and ready
to execute. Because operating systems are designed as if they never start or stop, a boot
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loader might load the operating system, configure itself as a mere process within that system,
and then irrevocably transfer control to the operating system. The boot loader then terminates
normally as any other process would.
Network booting
Most computers are also capable of booting over a computer network. In this scenario, the
operating system is stored on the disk of a server, and certain parts of it are transferred to the
client using a simple protocol such as the Trivial File Transfer Protocol (TFTP). After these
parts have been transferred, the operating system takes over the control of the booting
process.
As with the second-stage boot loader, network booting begins by using generic network
access methods provided by the network interface's boot ROM, which typically contains
a Preboot Execution Environment (PXE) image. No drivers are required, but the system
functionality is limited until the operating system kernel and drivers are transferred and
started. As a result, once the ROM-based booting has completed it is entirely possible to
network boot into an operating system that itself does not have the ability to use the network
interface.
Personal computers (PC)
Boot devices
The boot device is the device from which the operating system is loaded. A modern
PC's UEFI or BIOS firmware supports booting from various devices, typically a local solid
state drive or hard disk drive via the GPT or Master Boot Record (MBR) on such a drive or
disk, an optical disc drive (using El Torito), a USB mass storage device (FTL-based flash
drive, SD card, or multi-media card slot; hard disk drive, optical disc drive, etc.), or a
network interface card (using PXE). Older, less common BIOS-bootable devices
include floppy disk drives, SCSIdevices, Zip drives, and LS-120 drives.
Boot sequence
Upon starting, an IBM-compatible personal computer's x86 CPU executes, in real mode, the
instruction located at reset vector, usually pointing to the firmware (UEFI or BIOS) entry
point inside the ROM. This memory location typically contains a jump instruction that
transfers execution to the location of the firmware (UEFI or BIOS) start-up program. This
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