Townsville University SP1 2019 Advanced Data Communication Assignment

This document presents a comprehensive solution to an advanced data communication principles assignment. It begins with a detailed analysis of CRC-8, including codeword generation and error detection capabilities. The assignment then explores PBX systems, comparing their advantages and disadvantages with those of VoIP (Voice over Internet Protocol) phones, emphasizing scalability, features, and cost considerations. Finally, the solution provides a step-by-step guide to creating a spoofed email address, discussing the use of relay servers and email header modification techniques. The solution demonstrates an understanding of data communication concepts and practical applications, covering topics from error detection to network infrastructure and email security.

ADVANCED DATA COMMUNICATION PRINCIPLE
Name
Email address
lecturer
Question 1
(a) This equation can be solved using two different methods. By paying close attention to the
Msbit using the first order, we start by appending the 8bit inform of message.
The polynomial: X8+X2+X+1 results or generates the following code word can be generated
as asserted by [11]
100000111 this results to two different messages.
1110101112=x6+x4+x2+x+1
Code generation

(1b) in order to demonstrate how the receiver will extract the message appearing from the code
word the following is an outline of the steps that would be followed. We first start by appending
the message using the CRC code instead of using zeros thus 0101011110100010. It will then be
followed by performing long divisions through the use of the generator. To prove that there was
no error within the calculation, the end result ought to be a zero as demonstrated below.
The zero result proves that there was no error during the generation of the code.
(1c)
To prove that this generator is able to detect single bit error Pierce [10], through expanding the
generated message without addition of any information through utilization of the cyclic codes.
Additionally, CRC are normally reversible through the use of linear function thus can detect
any error within the generated code word raised to .

(1d) the receiver can detect the error in in any code that has been feed to it since it uses
polynomial functions to expand the given code and thus detect any function error thus correcting
it. It does not matter whether the code is single bit or two bit since the
Furthermore, the use of the harming distance theorem that most of this CRC uses. In this case the
code with distance n can be used to correct the error within a two bit code using this CRC 8bit
code.

Question 2
PBX
PBX or private branch exchange refers to systems of telephones that are used within an
enterprise or company. There main intention is to facilitate communication or calls between the
users or employees of a particular company using a localized line with the ability to enable the
users to exchange and disseminate information over a limited number of external users. The
main aim of using this kind of technology was to reduce the cost needed to purchase a line for
each user who is in need of calling the main office. It is supplied by the telephone operators but
managed by the company that has bought it. Despite the emerging trends in technology, the PBX
have following advantages within the company.
In terms of cost, especially for multinational and large businesses, especially those that are
decentralized and have sub-branches. It is a bit cheap since most of the calls can go without
being charged at the end of the month. Additionally, the PBX has got an initial cost which is fur
much cheap compared to purchasing an entire system.
When it comes to reliability, despite the fact that PBX has got an initial cost, its reliability is
questionable since they rely completely on the internet provided by the organization. Their
advantage is that they can still function even if there is no power since they are powered the
telephone lines.

Another disadvantage of using PBX is because of the quality of voice produced by it. The quality
of the voice is of a very low capacity. Additionally, they do not facilitate fast communication.
They are a bit slow.
[1] asserts that the main disadvantage of using PBX is that it is traditionally limited to using
analog technology.it is comprised of a computer that has got memory installed responsible for
switching of the calls and a telephone trunk that is used to cut the PBX communication.
With the emerging trends in technology especially in the area of communication, it is necessary
that companies should consider advancing themselves in terms of infrastructure especially in the
area of communication since the success of any given company depends heavily on the strength
of disseminating that a company has. With the increasing rate of advancement of technology,
companies ought to assimilate internet phones within their organization but with due precautions
after understanding the pros and cons that each technology has. This report has majored its
investigation on the importance of using internet phones in the company and why the company
should adopt this kind of technology.
With the development of communication technology, it is advisable that each firm should adopt
internet form if it so desires to compete favorably with other firms within the market arena. The
advancement in technology has led to the development of VoIP phones which are far much faster
in passing information as compared to the PBX. The VoIP phones refers to communication
gadgets that utilize packet-switch to transfer phone-calls via the internet unlike the order versions
that were relied on by the telephone networks. This internet phones uphold allot of advantages
compared to the PBX as argued by[12,13].

The annotation upheld by this phones (internet phone) can either be a physical phone that has got
an inbuilt IP and Ethernet/ a computer that can allow communication via voice [15]. With this
virtual features such skype, it becomes possible for communication to occur between phones,
internet phones o personal computers, computers to computers or computers to telephone calls.
As denoted by Eun-A Park [4] an owner of an organization it is rudimentary to have the
knowledge or have the understanding of the choices to be made out there in case one needs to
select between a private branch exchange and an internet phone. With internet phone, whenever
any communication is taking place, the sounds and voices are usually converted into data that is
put into packets and transmitted using network data. Through my investigation on the newly
invented internet phones, it has come to my notice that this devices contain both pros and cons.
Among many other terms, flexibility is one of the conspicuous terms that can be used represent
all the advantages that internet phones have over the PBX.
One of the pros of the internet phone that can attract and entice any company to use it is
scalability. These phones are usually licensed.in this case, all of its features are usually
controlled using a license. Unlike the PBX which required physical ports for cards to be inserted
in case one wanted to add an extension, for internet phones, they are more reliable since one only
need to add a license thus leading to the creation of the intended feature. [14] asserts that with
this kind of innovation, it becomes fur much easier to utilize a license solution as it can be
expanded without difficult. Additionally, the solutions that have been delivered as services can
be scaled back which can be advantageous to a business which is seasonal.
Another advantage of the internet phones is the fact that it contains a lot of features as compared
to the PBX. They are designed in such a manner that they can facilitate integration of other
technologies based on the same data network bringing communication to another advanced level.

Running a firm or an organization always requires constant communication between the clients
and the service provider. Quittner [9] denotes that when a company uses internet phone, they can
reach their target due to redundancy. The ability to make the whole world become a small
village. The internet phone is always available whenever it is needed. The provision of IP has
enabled the incorporation of redundancy both externally and internally thus one can monitor all
the activities of the subsidiary companies within the central office. In addition to this is the
benefit of visualization that is associated with interne phones, it is possible to deliver both phone
system in terms of virtual or the phone can be hosted inform of data.
Conspicuously the internet phone has come with the advantage of and the capability to allow an
individual use any SIP device which does not restrict the user to the systems and the application
manufactured by the producer. The internet phone can further allow a business firm to integrate
other technologies within the data network. In line with this advantage of the voice over the
internet phone, stocks of competence within a firm or organizations that have been decentralized
can still hold meetings and consult with each other without any problem through electronic
conferences using tools such as skype [16].
Based on the research done by Feijóo [3] Additionally the voice over the internet protocol has
the advantage in the firm since it is easier to install and configure the applications required.one
can easily create a platform that is customized and fit to the application of the business activities
As demonstrated by [6], despite all this achievements that have come with the internet phone
which can enhance the success of any given firm, it is important to acknowledge the fact that
new inventories do not always have 100% rate of perfections but rather they do have some
setbacks. As in the case of internet phone to be used in firms and businesses, there are number
of cons for instance, for the firm to realize full success of the internet phone in place of PBX, the

involvement of the IT department is very crucial in trying to find solutions to the existing
problems. How committed is the IT department in trying to find solution to the existing
challenges brought through the use of VoIP, Moore [5,17]
Consequently, the internet phone to some extent always experience some points of failures. They
tend to impact on the company’s data network and sometimes they tend to utilize the switches
for the phone servers which may result to failures to some extent. Another disadvantage of using
internet phone is cost, they are relatively expensive compared to PBX and they tend to rely on
vendor selection. It has facilitated the dabbling in telephony when it comes to sales and
marketing as an industry.it has opened the gateway to goods which are counterfeit and poor
quality thus not meeting the need of the firm.
In conclusion companies or firms should implement the use of internet phones since they hold
much advantages to the firm as discussed above compared to their cons

Question 3
Below is a step by step process of creating a spoofed email address that can be send under the
title lecturer.
To send spoofed email, we can start by using either SMTP server for instance QK server from
SMTP. In this tusk, we need to create link that will help us to bypass all the filters that have been
created by service providers such as Gmail and yahoo that tend to block mails that have been
send directly from home/personal computers.
To begin with, [18,19] suggest that we need to depend or utilize a relay server to facilitate the
sending of a mail that has been spoofed. Server relay refers to a trusted simple mail transfer
protocol that can be used to bypass the filters of the service providers since it forces them to
blindly allow the mail to be delivered to the recipient’s inbox. Since it is necessary to utilize a
relay server, in this context, we start by selecting a free web host provider that enhances the
sending of email. In this case we need to find a free web that can allow the sending of email.it is
just done with the intention of protecting one against spamming Chan-Olmsted & Miao [2].
According to Cecere & Corrocher [1] after finding a free web that allows the sending of email,
the next step is to edit and modify the header of the email so that we can insert the fake one.
Below is a PHP script that can be utilized to send emails using any desired name and any email
address that one desires. The procedure is as follows

(a) Visit X10 hosting for the purpose of registering a new account to be used.
(b) It is then followed by downloading anonymous email script
(c) The third step is to sign to our webhost area account which is free then press the file
manager.

List of references
[1]Cecere, G. and Corrocher, N. ‘The intensity of VoIP usage in Great Britain: Users’
characteristics and firms’ strategies’, Telecommunications Policy, (2011) 35(6), pp. 522–531.
[2]Chan-Olmsted, S. M. and Miao Guo ‘Strategic Bundling of Telecommunications Services:
Triple-Play Strategies in the Cable Tv and Telephone Industries’, Journal of Media Business
Studies, (2011) 8(2), pp. 63–81.
[3] Feijóo, C., ‘VoIP at the crossroads: A critical overview of feasible European regulatory
models’, Information & Communications Technology law (2011) 16 (1), pp 33–46.
[4] Eun-A Park ‘Business Strategies of Korean TV Players in the Age of Over-The-Top (OTT)
Video Service’, International Journal of Communication (2018) (19328036), 12, pp. 4646–
4667.
[5] Moore, L. K. ‘Emergency Communications: Broadband and the Future of 911’, Journal of
Communications Research, (2011) 2(2/3), pp. 179–210.
[6] Mijung Kim, Jun Heo and Chan-Olmsted, S. M. ‘Perceived Effectiveness And Business
Structure Among Advertising Agencies: A Case Study Of Mobile Advertising In South Korea.
(cover story)’, (2010) Journal of Media Business Studies, 7(2), pp. 1–20.

[7]Frieden, R. ‘The Costs and Benefits of Separating Wireless Telephone Service From Handset
Sales and Imposing Network Neutrality Obligations’, (2010)Conference Papers -- International
Communication Association, pp. 1–46.
[8]Lane, A., (2019) VoIP, PDQ’, Crain’s Detroit Business, 21(4), p. 11
[9]Quittner,J (2016)‘Firms Log telecom savings by heeding VOIP in wilderness’, Crain’s New
York Business, 20(39),
[10]Pierce, L (2017)The Protracted Enterprise Migration To VOIP’, Business Communications
Review, 37(2), pp. 34–39.
[11]Robinson, P. B. and David H. Yedwab ‘Understanding Vendor Strategies For
VOIP’, Business Communications Review,(2014)34(8), pp. 28–32.
[12]Lou, C.-Y., Daneshrad, B. and Wesel, R. D ‘Convolutional-Code-Specific CRC Code
Design’, IEEE Transactions on Communications, . (2015) 63(10), pp. 3459–3470.
[13] Kumkrong, P., ‘Selenium analysis in waters. Part 1: Regulations and standard
methods’, Science of the Total Environment, (2018) 640, pp. 1611–1634.
[14] PR Newswire ‘CRC Reenergizes Lubricants and Penetrants Line with Enhanced Packaging
and QR Code Technology’, (2013) PR Newswire US, 5 March.
[15] Bolton, C. and Sinclair, K. (2017) PLD Code Implements Arbitrary CRC
Functions’, Electronic Design, 49(11), p. 91.
[16] Gangopadhyay, D. and Reyhani-Masoleh, A. ‘Multiple-Bit Parity-Based Concurrent Fault
Detection Architecture for Parallel CRC Computation’, (2016) IEEE Transactions on
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