Acknowledgment This assignment couldn’t have been completed without the assistance and effort of many people. All the support and contribution that was provided is very much valued and appreciated by our group. The completion and finishing of the assignment couldn’t have been possible without the big role played by the guidance and encouragement given to us. Our group would love to express its deepest appreciation and recognition to everyone who made this assignment reach the highest levels of success. We would love to take this chance to show our huge appreciation to Mr Mansoor for the role he played in providing the required support and assistance to us and for showing willingness to use his free time to provide us with feedback. We would also like to thank all the lab staff in PC Lab 2 for letting us use the lab when its free. We would also want to express our deepest gratitude to our classmates, relatives, and all family members for the moral support they have provided us with. Abstract In this assignment, a critical evaluation and analysis will be carried out based on the Quality of Service (QoS) of a Wide Area Network (WAN) with the help of the simulation software Riverbed Modeler. to study the network parameters, a network model should be developed first. When the network model is created, an analysis of the network will be done through comparing and contrasting different simulation outputs. After that, the network will be further improved to minimize the delay as well as errors and to improve the traffic handling. In Addition, different scenarios will be created to ensure having a network that is able to handle traffic with no delay at the lowest cost possible. Each scenario will have different capabilities and parameters, therefore each scenario will be critically evaluated, studied and analysed. Finally, an understandable comparison between scenarios will be carried out in the results followed by a well delivered conclusion. Chapter1 Introduction The Aim of the assignment is to determine the quality of service performance and evaluation of WAN of Al Shifa L.L.C pharmaceutical Destitution Company in Oman operating in Muscat , Dubai and Salalah . The head quarter in Muscat and a branch in Sur by integrating the concepts learned in the modeling and simulation methodology. The objectives of the assignment are: · Study the parameters by developing conceptual model of complex computer network. · The network model will be created by the simulation tools. · The output is based on analysis and configuration of the network model. · Analysis the result that will be carried out · Documentation of the whole work · Drawing the conclusion from the result · Recommendation to prevent the problems The approach to determine the quality of service performance and evaluation of WAN of Al Shifa pharmaceutical Destitution Company broken down into five steps starting with: i. Formulation of the problem Al Shifa pharmaceutical Des.

1. Acknowledgment
This assignment couldn’t have been completed without the
assistance and effort of many people. All the support and
contribution that was provided is very much valued and
appreciated by our group. The completion and finishing of the
assignment couldn’t have been possible without the big role
played by the guidance and encouragement given to us. Our
group would love to express its deepest appreciation and
recognition to everyone who made this assignment reach the
highest levels of success.
We would love to take this chance to show our huge
appreciation to Mr Mansoor for the role he played in providing
the required support and assistance to us and for showing
willingness to use his free time to provide us with feedback. We
would also like to thank all the lab staff in PC Lab 2 for letting
us use the lab when its free.
We would also want to express our deepest gratitude to our
classmates, relatives, and all family members for the moral
support they have provided us with.
Abstract

2. In this assignment, a critical evaluation and analysis will be
carried out based on the Quality of Service (QoS) of a Wide
Area Network (WAN) with the help of the simulation software
Riverbed Modeler. to study the network parameters, a network
model should be developed first. When the network model is
created, an analysis of the network will be done through
comparing and contrasting different simulation outputs. After
that, the network will be further improved to minimize the delay
as well as errors and to improve the traffic handling. In
Addition, different scenarios will be created to ensure having a
network that is able to handle traffic with no delay at the lowest
cost possible. Each scenario will have different capabilities and
parameters, therefore each scenario will be critically evaluated,
studied and analysed. Finally, an understandable comparison
between scenarios will be carried out in the results followed by
a well delivered conclusion.
Chapter1 Introduction
The Aim of the assignment is to determine the quality of service
performance and evaluation of WAN of Al Shifa L.L.C
pharmaceutical Destitution Company in Oman operating in
Muscat , Dubai and Salalah . The head quarter in Muscat and a
branch in Sur by integrating the concepts learned in the
modeling and simulation methodology.
The objectives of the assignment are:
· Study the parameters by developing conceptual model of
complex computer network.
· The network model will be created by the simulation tools.
· The output is based on analysis and configuration of the
network model.
· Analysis the result that will be carried out
· Documentation of the whole work
· Drawing the conclusion from the result
· Recommendation to prevent the problems

3. The approach to determine the quality of service performance
and evaluation of WAN of Al Shifa pharmaceutical Destitution
Company broken down into five steps starting with:
i. Formulation of the problem
Al Shifa pharmaceutical Destitution Company wants to
introduce real-time applications in their branches - Muscat
,dubai and salalah - such as video conferencing and VoIP to all
the employees.
ii. Modelling:
In this phase the model is made and the following factors must
be considered
· Accuracy of the model and the features
· Acceptability of the model in its presentation phase
· Speed and level of the detail involved
· Collection of the data and accurate simulation
· Verification of the model and management confirmation
iii. Programing:
Consider the packages to be used and the type of programming
to be used and to compeer the result obtained from the model.
Implementing solving and developing the conceptual model of
complex computer network by using the riverbed modeler
academic - edition17.5 - software program which is includes
tools for study, model design, simulation, data collection, and
data analysis.
iv. Experimentation:
The testing phase of the model at this stage is done, and a base
run will be made to see the behavior of the system. And
comparison of the results will be made in stages and for several
times until the wanted result is seen in addition, sensitivity
analysis helps to figure out the issues so it can be fixed.
v. Implementation

4. Al Shifa Company has option to implementing the idea or not.
Chapter 2: Network Model with Details Of Setup And
Configuration
A WAN of alshifa LLC is designed using the riverbed software.
The company consists of one headquarter in Muscat and 2
branches in Salalah and Dubai. Three fixed subnets are added
which represent the company headquarter in Muscat and
branches in Salalah and Dubai. All three locations provide four
different applications, Web, Email, Print and FTP. Application
definition is added to the network and is configured in order for
the applications to be supported. And to support these selected
applications, profile configuration is added and configured to
the network. Profile configuration is also added in both
branches to support the selected applications. Figure 2.1 shows
the headquarter and two branches:
Figure 2.1 Network Model
In the headquarter, 15 clients are added that have attributes
allowing them to use various applications like Web, Print,
Email, and FTP. All the workstations added are connected to an
ethernet32switch using a 100BaseT link. Ethernet 32 switch is
selected over Ethernet 16 switch is because Ethernet 16 switch

5. wouldn’t be sufficient for the headquarter as there are 15
workstations as well as servers and a router connected to the
switch. 100baset links are used because using 10base links
wouldn’t be sufficient to carry all the data and using 1000base
links would cost more and provide more unused bandwidth, thus
the 100 baseT link is used. Additionally, a ppp server is added
to the headquarter, it is the server node which has server
applications. A single Ethernet4_slip8 gateway is added and
connected the Ethernet32 switch with the use of 100baseT link.
Figure 2.2 shows the Headquarter:
Figure 2.2 Headquarter model
Salalah and Dubai branches are created with the similar network
structure of that in headquarter. However, only 10 workstations
are added in each branch with attributes to do applications like
FTP, Print, Web, and Email. The clients in both branches are
connected to an Ethernet 16 switch using 100base t links. After
that, the Ethernet16 switch is connected to Salalah
Ethernet4_slip8 gateway using a 100Base T link. Same thing is
repeated again in the Dubai branch. The configuration of
Salalah/Dubai branches is shown in figure 2.3:
Figure 2.3 Salalah/Dubai branch

6. A duplicate of the previous scenario is made to modify the
network and make it support real time applications which are
VoIP and video conferencing. First, the application definition
node is configured by adding video conferencing with low
resolution and VoIP of GSM quality speech in the application
definition. However, to support these 2 applications, two
profiles should be added in profile configuration, the first
profile being VoIP and the second one being video
conferencing. In the headquarter 2 workstations were added, one
VoIP and one video conferencing as shown in figure 2.4:
Figure 2.4 Voice and Video
Figure 2.5 demonstrates the second scenario of Salalah branch,
where two clients are added that support video conferencing and
VoIP
Figure 2.5 Salalah/Dubai with Voice and Video
Scenario 3 is then created by duplicating scenario 2. In scenario
3, after VoIP and video conferencing were added to the
network, delay was observed in the network. And since delay is
not tolerated when it comes to real time applications because
they are time-sensitive applications, QoS was introduced to
combat the delay. To introduce QoS to the network, the QoS
node should be first added to the network. After its added, the
First-In-First-Out (FIFO) method is applied to the PPP DS1
links interconnecting the headquarter and braches to minimize

7. delay as shown in figure 2.6.
Figure 2.6 QoS applied to the network
Scenario 4 and 5 are created by duplicating scenario 2 again.
The same mechanism applied in scenario 3 is applied in
scenario 4, the only difference is that in scenario 4 the queuing
method is Weighted Fair Queuing (WFQ) and in scenario 5 the
queuing method is Priority Queuing (PQ) which is applied to the
PPP DS1 links interconnecting the headquarter and offices.
Chapter 3: Results and Analysis
To analyse the results of ALSHIFA LLC network, selection of
many statistics was done. These statics included the traffic sent
(bytes/sec) of Email, Print, Web and FTP. Moreover, other
statics were also considered such as the throughput and
utilization for all the applications in the network using the DDD
DS1 links going from Dubai to Muscat or from Salalah to
Muscat. For real time applications, other statics have been
selected to be analysed. In video conferencing, packet end-to-
end delay as well as packet delay variation were observed. In
voice, packet end-to-end delay, jitter and packet delay variation
statics were selected. The duration of the simulation was 5
minutes for all the scenarios.

8. 4.1 Conclusion
The Aim of the assignment is to determine the quality of service
performance and evaluation of WAN of Al Shifa Company in
Oman operating in Muscat , DUBAI AND SALALH. The head
quarter in Muscat and a branch in dubai and salalah by
integrating the concepts learned in the modeling and simulation
methodology. The objectives of the assignment are study the
parameters by developing conceptual model of complex
computer network. And network model will be created by the
simulation tools. In addition, output is based on analysis and
configuration of the network model. As well as analysis of the
result that will be carried out then documentation of the whole
work. Conclude with, drawing the conclusion from the result
and writ recommendations to prevent the problems.
From the result obtained after configuring the real-time
applications in Al Shifa Company network for all branches, the
company is not capable of supporting real-time multimedia
service such as Video conferencing and VoIP services to all
consumers between the two branches. As telecommunication
engineers who study simulating multimedia networks, to solve
the problem in configuring the real-time applications such as
Video conferencing and VoIP services in Al Shifa Company
network it will be improved the quality of service (QoS) by
using Weighted Fair Queuing (WFQ).
WFQ improve the multimedia service in Al Shifa Company
network. In addition, the average of voice packet end-to-end
delay decreases 10 phases. Furthermore, the WFQ improve the

9. multimedia service in Al Shifa Company network. In addition,
the average of voice packet delay variation decreases 35 phases.
4.1 Recommendations
The company can improve the QoS of their network by:
· A network monitoring system: Target the QoS at a network
interface by using server or router’s performance.
· Give more bandwidth to the important Packets to transfer first.
· Evolved connectivity from 100Base-T to Gigabit Ethernet.
However, this speed requires a significant investment.
· Improving Network efficiency via IPQoS.
Information Asymmetry
Discussion topic:
You have explored the concept of an information asymmetry
that existed at one time in the used-car market, prompting
George Akerlof to write his "lemons" theory. Can you think of
another market in which an information asymmetry exists?
Describe the market and how you see the information
asymmetry existing. How does this affect pricing? How do you
see the information asymmetry affecting the behavior of buyers
and sellers?
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[Type text] [Type text] [Type text]
Assignment 1: Investigate Market Questions
Instructions:
You will investigate market questions by examining a company

10. that has recently listed its IPO.
Complete the following grid. You will submit it for grading
according to the instructions below.
Investigate Market Questions
Identify a company that has recently listed its IPO.
Identify its listing price.
Identify the performance of the stock just after its listing.
Identify the price four weeks after and chart it.
What happened to the price during that time frame?
Why do you think that happened? Offer your best explanation or
rationale. You may choose to do additional research into the

11. company to learn more.
The Tax Shield
Discussion topic:
The U.S. government allows interest payments to be deducted
from taxes, but it does not allow this advantage for dividends.
This has a significant impact on capital structure decisions.
In this discussion, propose one way that this policy could be
changed in the future and, if it were changed, what the
implications of that change would be. (If another learner has
already posted an idea that interests you, please respond to that
post rather than create a new initial post on what is essentially
the same topic.)
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Financial Distress Observations
Discussion topic:

12. We've seen some of the common effects of financial distress on
a firm:
· A firm may have to lower prices to attract customers or it may
lose its customers outright. Financial distress leads to
particularly severe customer revenue losses for firms that sell
products with quality that is important yet hard to observe, and
for firms that sell products that require future servicing.
· Financial distress leads to severe supplier problems for firms
that rely heavily on trade credit; the likelihood that trade credit
will be terminated increases.
· Most employees will look for other jobs. The most competent,
highly motivated employees will likely find jobs. The less
competent, less motivated employees will likely not. Even if
the firm never actually declares bankruptcy, it will be left with
only the employees who were unable to find work, and those
employees will run the firm. Again, we have the firm’s capital
structure affecting its operations. When a firm with significant
debt in its capital structure experiences a downturn in its
operations, it increases the likelihood that it will lose its best
employees. Financial distress leads to severe problems for firms
that rely on highly trained, specialized employees.
In a few paragraphs, reflect on these common problems that
companies in financial distress experience. Have you observed
any of these in real life, whether as a supplier, vendor, worker,
or customer of a firm? What did you observe that led you to
understand that the firm was in financial distress? What was the
outcome in that case?
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Click Reply to post a comment and reply to another comment.
Please consider that this is a professional forum; courtesy and
professional language and tone are expected.