Post on 11-Apr-2022
Installation of VOIP Telephony System and Its
Integration With Active Directory
Hydro System KG, Ahfeldstrasse 10, 77781
Biberach ,Germany
Chhetri,Anup(176729)
Communication and Media Engineering (CME)
Hochschule Offenburg
Badstrasse-24,77652 Offenburg
In consideration of the partial fulfillment of the requirement for the degree of
Master of Science
In
Communication and Media Engineering (CME)
Date:May 27th 2015
.
Acknowledgement
The internship opportunity I had with Hydro System KG was a great chance for learning and
professional development. Therefore, I consider myself as a very lucky individual as I was provided
with an opportunity to be a part of it. I am also grateful for having a chance to meet so many
wonderful people and professionals who led me though this internship period.
Bearing in mind previous I am using this opportunity to express my deepest gratitude and
special thanks to Karl Haas who in spite of being extraordinarily busy with his duties, took time
out to hear, guide and keep me on the correct path and allowing me to carry out my project at his
esteemed organization and extending during the training.
I am also grateful to everyone who supported me throughout the course of this internship period.
I am thankful to Daniel Haine, the director of IT for giving me the opportunity to do my internship
within this organization. It was a wonderful moment to be a part of Hydro System. I am also
thankful for inspiring guidance, invaluably constructive criticism and friendly advice during this
period. I am sincerely grateful to them, who shared their truthful and illuminating views on a
number of issues related to this project.
It is my radiant sentiment to place on record my best regards, deepest sense of gratitude to Nils
Gerstenberg, Franz Amann, Jens Schmidt, Emil Kocher, Gopalkrishna Gajipara, Marc McInturff
and other IT members for their careful and precious guidance which were extremely valuable for
my study both theoretically and practically.
I perceive this opportunity as a big milestone in my career development. I will strive to use
gained skills and knowledge in the best possible way, and I will continue to work on their improve-
ment, in order to attain desired career objectives. Hope to continue cooperation with all of you in
the future.
Sincerely,
Anup Chhetri
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Abstract
The growing IT is covering the surrounding and changing the world drastically. In this flowing of
IT trend, telephony system also cannot remain untouched. The transport of telephony services over
traditional data networks such as Internet, corporate-enterprise intranets and new service providers
extranets has led to the development of cost efficient gateway equipments based on embedded an
system that converts analog telephony information such as voice and fax into packet data suitable for
transport over IP. Moving to an IP telephony infrastructure represents a significant shift from more
traditional voice services. A main business driver for transitioning from a traditional circuit-based
PBX solution to packet-based IP telephony services is integration of enterprise communication with
business processes and applications, and capture of information about every point of contact using
the system. Ultimately this information is used to enable technologies such as presence and chat.
Moving to IP and network-based telephony unifies voice and data on a common infrastructure, not
only eliminating extra cable runs throughout an office building but opening the door to a level of
integration not usually possible on dedicated voice systems. IP telephony has become a reliable
communication option that has well-established standardized communication protocol. In spite of
this reliability features, IP systems have low cost devices and software applications development
tools that are better than traditional tools.
This report describes the different aspects of the IP telephony. Various steps during this project
like planning, managing, implementing goals are described here. This will also help to understand
what IP Telephony is, how it operates, what service can provide and what the companies can
benefited from this technology. Along with this, it also describes the management, cost reduction
and implementation risk about IP Telephony.
The second section of this report describes about programming in PowerShell and few ideas
about active directory also. This topic was included here because AD and PowerShell are related
to our new telephony system.
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Table Of Contents
Acknowledgement i
Abstract ii
List of Figures v
1 Introduction 1
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 ProjectGoals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.3 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Description 2
2.1 Introduction to Hydro System KG . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.2 Description of Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3 Challenge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Task, Process and Activities 5
3.1 Project Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2 Research and Analyzing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.3 Training and information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.4 Ghantt Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.5 Post Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.6 Risk Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.7 Challenge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4 Basic Concept of IP Telephony 9
4.1 What is IP Telephony? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2 Why do I need IP Telephony? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.3 Building Block of IP Telephony . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.4 How does it work? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.5 Standardized Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.6 Security In IP Telephony? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.7 Problems and solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
iii
5 Understanding the market leaders in VOIP 16
5.1 List of Companies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6 Powershell Implementation 22
7 Discussion and Challenge 23
References 25
Appendices 26
A Softwares 26
B Hardware 27
C Additional Resource 27
iv
List of Figures
1 Share distribution of Hydro Aero . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Different stage in implementation of project planning . . . . . . . . . . . . . . . . . 4
3 Flow of project planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4 Gantt Chart for IP Telephony . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5 VOIP Task Performance over TDM . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6 Typical IP Telephony . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7 Building Block IP Telephony . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
8 Block Diagram IP Telephony . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
9 Protocols in IP Telephony . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
10 SWYX Telephony System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
11 Starface Telephony System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
12 Avaya Telephony System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
13 ROI Analysis Cisco . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
14 Cisco Telephony System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
15 PowerShell Syntax for cheking the existing user in AD . . . . . . . . . . . . . . . . 22
16 PowerShell Syntax for displaying all users . . . . . . . . . . . . . . . . . . . . . . . 23
17 PowerShell Syntax for exporting email of all users . . . . . . . . . . . . . . . . . . . 23
18 PowerShell Syntax for adding the new user in AD . . . . . . . . . . . . . . . . . . . 24
19 PowerShell Syntax for various operation in AD . . . . . . . . . . . . . . . . . . . . 25
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1 Introduction
1.1 Motivation
IP telephony is an emerging technology and has great power for the coming telephony system.
There are many technical and economic advantages that can define this new technology as the
cutting edge. In addition to the cost reduction, this project was motivated by the fascinating
new service offered from IP Telephony. Apart to this, this project has advantage over physical
implementation also. Last but not the least, the integrated unified services are always the reasons
of moving to this technology.
1.2 ProjectGoals
The main goal of this IP telephony project is to replace the company’s existing telephone system
with a new voice over Internet Protocol system. Apart from this company’s goal, this report
describes and reflects my learning objects and personal goals that I have set during my internship
period. My main goal for this project was to understand the different components that constitute
IP Telephony and understand the concept, how this functions. However at the beginning of the
internship I formulated several learning goals, which I wanted to achieve in this 3 months.
• IT project planning
• Implementing IP telephony
• System Administrator
In addition to working to meet my primary operational goal, I also engage myself to other IT
related jobs that I found really interesting. This project is planned to be finish in total 9 months
duration (1.March 2015 to 31. December 2015). So, this internship report does not contain all the
activities from start to end. However, I try to put the important activities that we already did or
plan to do it in coming future.
1.3 Background
Internet Telephony is not the new technology, it is known since long time because of its wide unified
service and advantage. But only recently, it is becoming reliable and ubiquitous enough to be a
serious choice for business. These days VoIP project are well planned and support high quality
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unified service replacing the traditional old telephone lines. The old technology PSTN is obsolete
and expensive. Modern Telephony uses ”Voice over IP”. So this complete project is IP based that
means we will not us any traditional PSTN line. IP telephony referred to telephone communications
over TCP/IP networks. In contrast to the PSTN, which consist of analog and digital signals over
a circuit -switched network, IP telephony is packet switched.
In this internship report I will describe my experiences during my internship period, also contains
an overview of the internship company and the activities, tasks and projects that I have worked on
during my internship.
2 Description
This report is a short description of my 3 month internship carried out as an elective component
of MSc. in Communication and Media Engineering (CME). Voice Over Internet Protocol (VoIP)
also normally known as Internet Telephony is ever growing technology now. Every company want
themselves to update to the new technology and is expected eventually to replace the switched
telephone network. In one side, this technology proves to be eliminating the long telephone bills
for the users and on other hand, it virtually wipe out charge for long distance and international
calls.
2.1 Introduction to Hydro System KG
Hydro Systems is a global leader for Aerospace Ground Support Equipment (GSE) and Airframe
and Engine maintenance tooling. Hydro started up in 1965 with group of employees in Biberach
near to the small village in Germany’s black forest. Continuesly growing from the sctrach , Hydro
has become the one of the market leader for GSE. For 50 years Hydro has designed and produced
innovative solutions for the maintenance, repair and assembly of aircraft and engines. With corpo-
rate headquarters in Germany, the Hydro Group has significant operations in the United States,
United Kingdom and around the world.
Hydro is a fast growing company with nearly 600 highly qualified employees. Over 1800 cus-
tomers in more than 120 countries depend on the product of Hydro. With over 19 product ranges,
Hydro deliver the perfect solution for the ground Support Equipments (GSE), maintenance tool-
ings. Today more than 25000 tools and 3000 GSE products can be found under the trademark of
Hydro.
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Figure 1: Share distribution of Hydro Aero
2.2 Description of Project
VoIP and IP telephony are becoming popular with large corporations and consumers alike. Voice
over Internet Protocol (VoIP) is a method for transmitting the voice signal and multimedia signal
over internet protocol (IP) networks. VoIP can turn a standard internet connection into a way to
place free phone calls. VOIP is a revolutionary technology that has the potential to completely
revoke the worlds phone systems. IP telephony uses the full advantage of VOIP and includes the
interconnection of phones for communications, related service such as billing and dialing plans,
and basic features such as conferencing, transfer, forward and hold. Nowadays in the World of IP
telephony and VoIP, new word unified communication is evolved. That takes this IP telephony to
one step further by using protocol such as Session Initiation Protocol (SIP). So, there was a great
need of this new technology in company like Hydro, which is growing every day. There were various
vendors, which could provide solutions to our requirement and it was not easy task to compare each
company and select the best. So, for the first month, our main task was to identify the companies,
make an appointment and discuss with them in detail about their products. Along with this , our
project planning was also going in parallel. Similarly in the second month, we try to make broaden
study with other companies who can supply the telephony products. In the third month, it was
more about cost and features analysis about the company. Different companys products were under
our analysis and we made a broad study comparing what we need and what they can offer us. The
possible candiadtes companies elected for this project were Cisco, Avaya, Swyx & Starface.
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2.3 Challenge
Technology management is crucial in offsetting the risks of new technology. Along with the advan-
tage of technology, challenges are also increasing. It is getting more complex and difficult everyday
to manage the technology. For any successful company, technology has an ambigous impact. Man-
aging new technology requires a complete understanding of technology and must be able to create
the logical soultion in case of any problem. In market many telephone system solution are available.
There are many companies which provide this solution. But, the detail study has to be made in
order to ensure that a right product comes to Hydro. This was the one side of challenge.
On the other hand, the existing telephony was the matter of problem. The already running
telephony was not completely compatible with this new cutingt edge technology and they need to
be replaced. It was problem from both physical and logical way. The running telephony has to be
immediately replaced without any break. So, the end user does not have to face any problem in
telephony. In addition, it is supposed to be challenge for retraining staff and make familier with
the new features of the system. However, we try to make the end device backward compatible and
simple, so every old user can enjoy without any new features. In addition, they can enjoy better
quality and new features also. Also, Keeping technologically update requires extensive research
and strategic analysis of the potential value. In addition, another challange was to keep running
the telephony system for longer time. So the project management should be aware of reserach,
development and forecasting the technology futures and choose the right products.
Figure 2: Different stage in implementation of project planning
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3 Task, Process and Activities
3.1 Project Planning
Topology, performance and budget considerations drive the choices of equipments and protocols
following the identification of stakeholders and requirements. Although the components may differ
in scalability and capability, they share the same characteristics and principle of operations. In
the process of the project planning, there are different steps, which combinly forms the total
project. The first step in the planning phase is to understand the high -level business and technical
expectations and requirements for the future IP telephony network. These can include the following
ideas:
• Review company vision, goals and forecasted growth
• Plan for voice and data network over next 3-5 Years
• Solution expectations
• Deployment and timing
• Financial expectations
Figure 3: Flow of project planning
One of the barriers identified in such IT project is lack of formal planning and control methods.
This can cause because of lack of knowledge or can also be because of lack of time. Sometime
having enough knowlege and time will not work because of the miss plan. So, this section was
important to finish the project succesfully in time.
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3.2 Research and Analyzing
The research and analyzing method should include the causal model of the project strategies
and practical plan for carrying out the study. This is used to generate sets of hypotheses about
the project outcome and impacts that can arise during the project periods. Once the possible
conditions are verified, next step is to find the measurable indicators that can help to reduce the
negative impact on the projects. So, the research can be made on the existing internet model in
Hydro. It is important to be sure that the, if the existing network is capable of transferring the
traffic or the new topology is needed. In context of security, it is mandatory steps to configure
the server protected from the other person. IP telephony is based on SIP technology which is
suppressing the classic Telephony making the need necessity. However migrating from the old close
line telephony to open wide band platform is increasing vulnerability as well. Due to this technical
and economical level, new risks and abuse potential telephony emerged and the need of proper
research on these topics is required.
3.3 Training and information
Once the project is started, it is important to carry out training and information. This can be
done to inform the results of the projects , most likely to higher management level or to train the
end users aboout the new features of the projetcs. The demand for the information is most likely
to arise from management or organization who donates the fund. From planning, schedulling and
controlling the project, for the proper balancing and maintenace, information flow is necessary. Fot
our project, we maintain the control of information flow between group memebrs and others also,
so that the project can be driven according to predefined schedulling techniques. This was also
important to keep the conflict minimum and use the budjet more securely and wisely.
3.4 Ghantt Diagram
The following table shows the timeline planning for our project planning. The total duration for
the project was planned for total 9 months. It was starting from 1. March 2015 and extending up
to 31. Decemebr 2015.
3.5 Post Analysis
Management is everywhere. Whether the project is at starting, or is already finished, management
is necessary. Once the project is finished then the project should give the positive result. In other
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Figure 4: Gantt Chart for IP Telephony
words Return of Investment (ROI) should be greater than zero. This can be done by directly profit
calculation or other methods also. Speaking in our project, our network must be able to deliver voice
traffic over IP network without affecting the data network. Unlike old technology, IP telephony
is a wide multi unified-communications, where multiple applications run in finite resources. So, it
is important to be sure that each service is running with their efficiency without affecting others
performance. There are several options for monitoring and managing IP telephony, including some
open source software also. So, network performance and end point voice performance should be
above the threshold in POST analysis.
3.6 Risk Analysis
Migrating company form one telephony system to new IP telephony is a sign of bussiness devel-
opment. However there are many risk that can arise during the migration or deployment of this
project. Many unpredicted obstacles may take the project to serious situation if not analyzed
properly. Risk analysis define the ways to include risk charactrization, risk communication,risk
management and policy related to risk. IP Telephony is less confined as compared to traditional
PSTN telephony. As a result, it is more exposed to security attacks. Voip protocols such as SPIT
possesses risk like ARP poisoning. Protection mechanism are often available, but they may seri-
ously impact on the quality of service of such critical environments. Despite of many advantage,
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Figure 5: VOIP Task Performance over TDM
probelm like ARP poisoning, flooding, SIP spoofing can create the real problem in VOIP. However
there are always the solution that can overcome this problems.
The following steps can be applied for risk analysis:
• Identify , classify and detail desription of risk
The risk can be security problem like packet flooding or SIP spoofing. Also, can be the
system failure. Higher the load in the system, chance are high that system may crash. As
the receiver gets the signal via RF, the position of access point should be carefully placed.
This is important to get the good signal quality for the end users.
• Lockup and evaluate the risk
Risk like Packet flooding can make the server overload, resulting the crack in the system. So,
after the careful consideration of problem, they have to be evaluated and know the level of
effects those problem may arise.
• Preventive and corrective measure for risk management
Telephony over IP is a critical service exposed to multiple security threats. Applying risk
management methods and techniques to VOIP infrastructure provide new opportunity for
addressing the trade-off between security and quality of such sensitive services.
However, the technology is not only the complicatiing factors. In a migration, each small
things requires many detailed and often times complex steps to be completed. These factors often
complicate the telephony system and impact goes directly on the project output.
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3.7 Challenge
Hydro is a company with almost 600 employees all over the world and they are using the old
telephony system, which is going to be replaced by new IP telephony. So, it is sure that, it is not
easy to train people to use the newly implemented system because of technical knowledge or so
on. So, it was extremely important to keep the system as simple as possible without degrading the
quality features.
The challenges are the part of any projects. While saying that true, the problem of data traffic
that is going to be created by IP telephony was another integral problem to be addressed. It is very
important to keep in mind that, bandwidth available is enough to carry the traffic generated. Thus,
we make ourselves sure that the IP telephony traffic never goes below the QOS threshold. As this
is IP technology, packet travel via internet. And, unfortunately internet has lots of security holes
where third man attack may happen. So, security was a matter of concern for this project. Thats
why our job was also to maintain the privacy and security and stop attack like VOIP phishing,
DoS (Denial of Service), SPIT (Spamming over Internet Telephony)or so on.
4 Basic Concept of IP Telephony
IP Telephony is a power and economical communication tool by combination of the telephone and
data networks. The ability to carry this data over IP brings both positive and negative features
to all the service provider and also end users. It is for sure that customers can enjoy cheap call,
whereas service provider has to pay their loss for this service. Despite of these difficulties, both
from social and technical side, it is guaranteed that, it will bring vast change in communication
market. So, the main aim of the IP telephony is to increase productivity which suggests that the
technology is better referenced in business environments.
4.1 What is IP Telephony?
In contrast to traditional circuit switched telephony, where an end to end circuit is set up between
two telephones, IP telephony uses the internet protocol to transmit voice as packets over an IP
network. In circuit switched connections, the connection was established for whole time when there
is no active connection also. But, in packet switched connection, it goes in different way. In an
IP telephony connection, voice signal is digitalized and send over network and share with other
IP traffic also. So, that makes more flexible for IP telephony over traditional circuit switching.
Also known as VoIP phone system, IP telephone systems typically comprise a VoIP private branch
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exchange ( an IP PBX) and desktop VOIP phones(IP phones) that connect to a VOIP service
provider via a networks. Normally two operations (coming from and going out) can take place at
same time, allowing a full duplex conversation. The traffic is supposed to be really high, because IP
telephony encompasses a number of services including phone-to-phone, pc-to-phone, phone-to-PC
, Pc-to-PC and fay-to-fax, as well as video conferencing.
Figure 6: Typical IP Telephony
4.2 Why do I need IP Telephony?
If your company is still covered with traditional phone, it can be good option to change your mind
and move towards the IP Telephony. There are many reasons that tell why you have to move
towards IP Telephony. It can provide businesses with many tangible benefits. If you are tired of
manually transferring calls from one desk to others, IP telephony can significantly reduce the time
and improve the performance. It is always clever to solve these two questions before we change our
mind to go to IP Telephony.
• Limitations of current phone
• Companies Goal and is your phone helping to get them?
knowing the answers to these questions will help you coordinate your needs and goals, both current
and future, with your IPT system. You’ll know what features and capabilities the phone system
needs from the start, and what you’ll likely need down the road. Here are some short listed reasons
that tell why have to update you to this new technology:
• Provide significant cost savings
• Able to integrate in other service like messaging or web enabled call centers
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• Saves time and money by using same LAN infrastructure & wiring to carry traffic
• Provide ”Follow Me” routing for calls for easy availability . . .
IP telephony brings together multiple real-time and offline communication modes such as tele-
phony, email, fax and instant messaging plus a range of additional capabilities (including presence
detection and click-to-call) into a single, integrated solution. With this solution, user can access and
manage all of their communications tools from a single environment, regardless of their location.
4.3 Building Block of IP Telephony
Basically IP telephony has some basic blocks which combined formed the complete one. Even
though the deployment environment and customer requirements for IP telephony solutions differ,
the design approach remains the same. Considering IP Telephony as an application implies that
a reliable IP infrastructure must be in place to carry the deployment of IP telephony. It is also
fact that people keep VOIP and IP Telephony in same baskets. But technically they are different
thing and need to be distinguishing each other. In fact, VOIP is a carrier in which IP Telephony
depends upon.
Figure 7: Building Block IP Telephony
IP Telephony is combination of VOIP standards, protocols and equipments to create a complex
or as simple telephony system. Here are some of the components that can be considered as the
integral part of IP Telephony:
• Gateways
Generally, a gateway connects IP phones to other telephone systems, which may include public
telephone and PBX also. To integrate legacy phone instruments into an IP-based telephone
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system, a voice gateway is required. The analog voice gateway allows for the integration of
analog phones, faxes, and modems with the IP-based Call processing platforms. Gateway
also can be configured to ”IP enable” to PBX. That means, they can route the packet over IP
data network instead of telephone networks. The direct advantage of this routing is ”Least
Cost Routing”, which allows us to centralize the telephone and reduce the administrative
costs.
• Gatekeepers
IT can be considered as the ”traffic cop” of IP Telephony systems. It is responsible to route
the calls and control who is allowed to use the system and when. It also manages how devices
use the network, ensuring that time-critical voice traffic has priority while controlling total
network usage and maintaining quality of service.
• IP PBX
This performs services for users such as call forwarding and voicemail. It also provides
switchboards services and call routing, e.g. Press 1 to connect customer care
• Software
VOIP system comprised both hardware and software. It is driven by the software which sits
upon the hardware interface. The hardware may include the hardware server like starfcae
appliamce v5 or Cisco BE6000 Medium Density Server. All these hardware are powered by
software inside.
• IP Phones
It operates just like traditional PBX phone. The only difference is the medium of connection.
It uses IP network to connect whereas other will use traditional phone lines. IP phones make
work easier, as they can be carried anywhere inside the network without any mess of wire or
disconnect.
• IP Softphone
An softphone is completely software based phone, that turns your PC into a virtual telephone.
In addition to advanced calling features and directory services, it typically offers video calling
also. So softphone is capable of performing the telephony function with other unified service
also. Softphone is not limited to computer only, however it can be in IPhone and Android
also. This is very important for us, since we are planning to give the user flexibilty to use
their own device and use it for the E-mail & call purpose also.
. . . . . . . . .
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4.4 How does it work?
This section describes the functioning of IP telephony. Ip telephony is packet based communication
system which in turns is the new advanced technology. Although IP telephony is not compatible
with old PSTN telephony lines, it can me linked using some converter devices. IP telephony can
be connected to PSTN (public switched telephone network) by a gateway that is placed between
PSTN and IP network. This is the physical interface between telephone network and IP network.
This gateway is responsible for following functions:
• signaling to and from telephone network
• interface between telephone number & IP addressing in IP network
• Voice Processing: reception/Compression/echo canceled. . . .
Compression for voice signal is important for two reasons
• To reduce amount of BW required
• To reduce delay impact from the network
Users of a VoIP phone can simply plug their IP phone into the nearest LAN port and IP phone is
registered automatically at the VoIP phone system. IP phone are equipped with such intelligence
that, IP phone always keep its number, and behaves exactly the same way, irrespective of place.
Figure 8: Block Diagram IP Telephony
IP Phones looks almost same like normal phone except the connectivity they got. The connector
for the IP phone is standard ethernet (RJ 45) cables. Normally IP phone is equiped with power
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over ethernet (POE). POE is the technology that delivers the siganl data and power in the same
line. In POE, one cable is sufficient for both puropse. And regarding CTI interface, IP phone can
be connected to computer via output port in telephone. This makes the internet connectivity as
well as phone conncetivity in computer also. IP phones connect directly to your router and have
all the hardware and software necessary right onboard to handle the IP call. Wi-Fi phones allow
subscribing callers to make VoIP calls from any Wi-Fi hot spot.
4.5 Standardized Protocols
IP telephony have their own standard protocols which performs signalling and call control tasks.
There are many standard protcols adopted by different companies such as Media gateway Control
Protocol(MGCP), Skinny Client Control Protocol (SCCP), Session Initiation Protocol (SIP), H.323
Protocol and many more. Among them, SIP & H.323 are the popular one. These protcols give
capability of route voice and data calls between two nodes.
• H.323
This protocl was desinged for the multimedia communications over IP networks, including
video and audio. Since H.323 is limited to mulztimedia conferencing, the complexicity factor
depend upon the system nature. The message encoding is binary format that is better
for narrowband and broadband connections. The basic compnents of H.323 are terminals,
gateways and gatekeepers. Similar to other protocols, H.323 applies to point-to-point or
multipoint sessions.
Figure 9: Protocols in IP Telephony
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• Session Initiation Protocol (SIP)
SIP is responsible to setup ’session’ betwenn two points and belive to be more flexible for the
VOIP technolpgy. SIP was initiay focused on voice communication and then expanded to
include video, application sharing, unified services and many more. SIP message are encoded
in ASCII text format. This ASCII based SIP works on client/server model as well as peer-
to-peer model also. It uses requests and responses to establish, maintain and terminate the
connection. The basic componnets of SIP are proxy server, redirect server, register server
and User Agent(UA).
4.6 Security In IP Telephony?
Security is a prime concern for any company. especially when there is matter of IT then, chaces are
high that data protaction & security are need to be addressed. Therefore in IP telephony also it is
matter of fact that security can be leaved opened. Here are some of the basic points that describe
the security in our project.
• Since most VOIP traffic is uncrypted, it is necessaey to configure the seetings. This is because
with small efforts and network monitering tools anyone can decode the traffic in the networks.
• SIP & IP spoofing can make the attackers way to listen the conversation.
• Denial of service (DDos) can make the floods of SIP requests arrive at a server or make the
server to send the flood of packets to numerous phones at same time, can make the server
down and even crash the server also.
These type of errors are part of IP telephony projects, but well managed ,secure networks are not
subject to this risk. Also packets can be transfeered using some encryption, secure session protocols
and other authentication mechanism which can put the extra firewall and stop to prevent hacking.
4.7 Problems and solutions
Voip is one of the best technical solution over the old telephony system. However. there can be
a severla problem in VOIP irrspective of its many advanatage. Any companies implementing this
new telephony system also has to be prepared for the problems that may arise during the project
time and after completion also. The Voip problem like echo, bad voice quality , call dropping ,
etc. may be seen freequently if the precations are not applied. Once the project is finished it is
important to check for the possible failure test that can occur in the system. The cause of poor
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performance in VOIp may affect the project severly. The problems identified must be immediately
solved. This problems should not be ungoing. Here are few common troubleshooting method for
checking the performabce of VOIP.
1 Jitter/ Latency Problem
Normalylly when the system is wireless or packet switched then the problem of Jitter may
arise. The efect of jitter is seen when the packet received are not in same order as they are
send, resulting the call with poor quality. These problem can be solved by allocating the jitter
buffer memory. Similarly, Latency can be the serious problem in network. Latency refers to
the amount of time packet takes to recha destination from the sender. That means user will
listen the voice with delay. The soultionj for this problem is to provide the voice packet with
high prioritize values. this force the network to carry the voice packet with high speed and
low latency.
• Network bandwidth
Bandwidth is the critical factor in VOIP project to reduce the poor performance. There are
different type of packets running on th network and we need to be sure that total bandwidth
provided is more than bandwidth used currently. If it is case of ISP, then bussiness class high
speed internet can be used as a VOIP data carrier.
• Internal Network configuration & Device Used
It is important to be sure about the network configuration and device used before making it
the stabdard telephony system. The current network may not be able to carry this packets and
need to be reconfigured also. Regarding the devices, access point may need to be configured
for proper sigalling of telephony.
This are the few steps that may be usefl for troubleshooting the system. However, these are not
the only that can occur in the system. Therefore, troubleshooting may be a broad topic based on
the project condition.
5 Understanding the market leaders in VOIP
IP telephony is an emerging market and it is attarcting many companies to develop the new products
for this rising market. As with the evolving software and telecommunications, VOIP systems are
also upgrading them with time. The core strength in specific categories of the IP market place
defines the ranking of the companies. There may be other companies that may be more bigger than
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this choosen, but we decided few of them for our projects. Also this comaopnies may not be the
only one with strong leadership, vision and sharp focus and ability to deliver the quality products
in time. As we look in the VOIP market the market level shifting was clearly visible. This change
reflects the maturing of the consumer VOIP market. But it may be too ealry to put IP telephony
in a basket of matured technology. Apart from VOIP telephony, this technology is expanding itself
towards unified services also. Here are some of the companies listed that we decide as the possible
candidates.
5.1 List of Companies
IP services continue to evolve, and the use of VoIP in clever and new ways has become a cornerstone
of innovation. Whether its business VoIP and unified communications, conferencing, a range of
consumer rich media options or developer APIs targeted at making mobile VoIP better, theres
simply a lot happening. Accordingly, a list of notable VoIP innovators offers a view into the leading
edge of the industry. Skype have emerged and introduced disruptive technologies. Companies like
Cisco, Avaya, Siemens , Starface have introduced the major market place to leverege their IP
telephony into VOIP services.
• SWYX
SWYX is a Dortmund based company that develops communication software specially for
small to medium sized companies. This is installed on windows server and work paralelly
with server. There are many IP telephony products avaiable with highly sophiscated features.
SwyxWares rich range of features go far beyond the power of a traditional PBX. The unique
features like Web conferencing and video telephony give employees greater scope and access
to resources. Application sharing & online collaboration makes this technology to the new
heights of success. SwyxWare integrates every employee device (including mobile phones)
through its ”single number” concept allowing the flexibility to choose what phone number is
displayed to the recipient. The result: Improved workflow creates higher productivity at lower
cost - a key competitive advantage for SMEs. SWYX has devloped ists prodcuts for unified
communications, cloud communications, mobile communications and future communications.
• Starface
Starface is the Karlsruhe based company with theme of ”Made in Germany”. It integrates
completly into the IT and communications infrastructure. This is not OS restricted commu-
nication system. That means it can be used in windows, Linux and MAC OS X environments.
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Figure 10: SWYX Telephony System
Starface can be used as standlone server , in cloud or as VM edition also. Starface service can
be used independent of telephone manufatures and providers. A ”single number” concept is
also available here. So, end user has flexiblity to use the same number to office, home-office or
any where. Starface can also be used as a cloud service. This is available in various classes as
Figure 11: Starface Telephony System
a highly available and highly secure managed service. And another possibility to use strafcae
is the Starface VM edition. This is operated in a virtualised server environment and can be
installed reduntaly, and can be connected to public telephone network via SIP lines.
• Avaya
Avaya is US based telephony company and leading provider of solutions for IP telephony
products. Avaya products integrate voice, video, messaging and customer contact applica-
tions in single packages. Everywhere at headquarters, remote office and on the roads all
have the same enhanced communication capabilities-so they can easily and quicly take care
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of bussiness. Having 700+ features ensure communications flow easily throughput the or-
ganization. Every nomral user can eyperience the unified service and hundred of advanced
features. Avaya promise to deliver the communication service with 99.999% realiability. Its
product gives travelling or telecommuting users the same great voice, video, messaging, and
collaboration features that they enjoy in the office.
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Figure 12: Avaya Telephony System
Avaya products are equiped with integration of audio, web and video conferencing also. This
collaboration of tools make the avayas product more popular in VOIP market. There are
many extra features like calender integration which let the people easily schedule and join
meetings. Regarding cloud, AvayaLive Connect can be used. It is hosted in the cloud, so
the only equipment you need is your phones. The service is delivered over the Internet and
accessible from anywhere.
• Cisco
Cisco is an american multinational technology company that designs manufaures and sells the
networing equipments along with IP telephony products also. Integrating Cisco’s products
and technologies throughtout our organization enables to make the better conncetrion within
the company and with customers that provide maximum benefits. Cisco claims that, its’s IP
Telephony offers an immediate ROI by reducing total cost of network ownership through one
converged networks. According to Cisco Systems, Initial return on investment (ROI) analyses
have determined that IP Communications deployments deliver an average payback within 12
to 18 months. On average, contributions to the total cost savings are:
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Figure 13: ROI Analysis Cisco
Cisco Unified IP phones provide the unmatched levels of integrated business capabilities and
converged communications features beyoind todays conventional voice systems. As a market
leader in IP telephony, Cisco continues to deliver unparallel end-to-end-to-end data and true
voice-over-IP (VoIP) solutions, offering the most complete, stylish, fully featured IP phone
portfolio to enterprise and small- and midsized-business customers.
Figure 14: Cisco Telephony System
The one best product from Cisco is Cisco Unified IP Phone 7960G. This is dynamic and designed
to grow with system capabilities. Features will keep pace with new changes via software updates
to the phones flash memory. Cisco small bussiness SPA300 series phhone are also great choice for
affordable and reliable IP and DECT operation.
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6 Powershell Implementation
Powershell is a task automation and configuration management console from microsoft. It is equiv-
alent to bash shell from Linux. It consists of command-line shell and associated scripting language
built on .NET Framework. In powershell , administrative tasks are generally performed by cmdlets.
For example import-module activedirecoty will import the active direcoty in powershell. This topic
was related to out telephony system, because the new IP telephony requires the complete infor-
mation about users who are going to use. In other words, information for the end users has to
be upload in active directory and it wll be sysnchronized in outlook, exchange and other place
also. This topic was more logical coding. Since powershell can perform all the administrative task
for the Active Directory and handy to use, we prefer powershell for managing our AD. Powershell
was also the best choice for automation of administrative task. Those tasks may include removing
accounts that are no longer needed, the bulk modification of an attribute, and renaming groups of
computers in reorganization. All of these tasks can be made easier and quicker! This section will
cover some of the powershell solution that are related to our projects. These powershell syntax use
the cmdlets like Get-AdComputer or Get-AdUser or can be New-Aduser.
Figure 15: PowerShell Syntax for cheking the existing user in AD
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Following piece od code will query against all the domain for all the users. Powershell is in fact
simple to implement and easier to function also.
Figure 16: PowerShell Syntax for displaying all users
Following code will export the E-mail address of all the users and save in the .CSV format
Figure 17: PowerShell Syntax for exporting email of all users
7 Discussion and Challenge
Successful deployment of a IP Telephony depends on careful evaluation of the technical prepared-
ness. For example, is the network ready? The infrastructure must be capable of delivering sufficient
throughput and meeting latency, jitter, and packet-loss threshold requirements. In one hand, IP
telephony client software may allow users with multimedia PCs to video and audio conference,
share documents and use a white board, enabling a more efficient work environment. On the other
hand, IP Telephony may fall down with traditional wired phone in context of availability. Migrat-
ing customers to IP telephony represents a large business opportunity. Yet the potential risks are
also many. Migrating the whole company and large number of sensitive data is not piece of cake.
The chance of making mistake and facing the unpredicted obstacles are really high as compared
to normal telephony system. Additionally, each individual phone set requires complex detailed
configuration to operate. However, the technology is not always the complicating factors. Some
non-technical issues significantly complicate a telephony migration and impact on the result. The
main problem that IP Telephony may have on end user is the voice quality issues, number plan
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Figure 18: PowerShell Syntax for adding the new user in AD
issues, personal features missing (speed dial, address book, etc.) Such type of problem may not
be visible in the test phase. Another main thing that cannot be bypass is the security. This is
sensitive and can cause lots of damage if not configured properly.
The significant cost arises here is the replacement of the phone handsets/instruments and providing
a hardware interface for all the required analog phones/instruments that cannot be replaced at this
time (special devices for elevators, some emergency phones etc.). Ideally, it cannot be guaranteed
that IP telephony have 100 % reliability. However, coordinating the setup between the PBX, Soft
switch, Messaging, and network equipment can minimize the errors and reduce the risks.
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Figure 19: PowerShell Syntax for various operation in AD
References
[1] http://www.method123.com/project-planning-phase.php Planning Phase - Project Plan-
ning Phase
[2] Robin Gareiss, Executive Vice President & Sr. Founding Partner, Nemertes Research
http://www.webtorials.com/main/resource/papers/ir/paper12/ROIofIPTelephonyManagement.pdf
The ROI of IP Telephony Management
[3] http://www.nascio.org/publications/documents/nascio-voip.pdf VoIP and IP TELE-
PHONY
[4] http://www.cisco.com/c/en/us/products/collaboration-endpoints/unified-ip-phone-7900-
series/index.html Cisco Unified IP Phone 7900 Series
[5] http://www.avaya.com/usa/product/phones/ Telephone Systems Avaya Phones Portfo-
lio Avaya
[6] http://www.avaya.com/usa/product/ip-office/ Avaya IP Office Midsize and Small Busi-
ness Phone Systems Avaya
[7] http://www.cisco.com/c/en/us/products/collaboration-endpoints/ip-phones/index.html IP
Phone - VoIP Phone Products - Cisco
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[8] https://www.starface.de/de/Produkte/appliances/index.php Die Telefonanlagen von STAR-
FACE Jetzt informieren!
[9] http://www.swyx.com/products/unified-communications/connectivity.html SWYX
[10] http://www.starface.de/en/ STARFACE PBX - the IP telephone system for your
business
[11] http://www.method123.com/project-planning-phase.php Planning Phase - Project Plan-
ning Phase
[12] http://www.swyx.com/products/unified-communications/phones-more.html Phones & More
[13] http://www.deliveron.com/blog/query-user-accounts-active-directory-powershell/ Deliveron
:: Query for User Accounts in Active Directory with PowerShell
[14] https://4sysops.com/archives/how-to-install-the-powershell-active-directory-module/ How to
install the PowerShell Active Directory module - 4sysops
[15] http://www.windowspro.de/script/anleitung-powershell-modul-fuer-active-directory-
installieren Anleitung: PowerShell-Modul fr Active Directory installieren
Appendices
A Softwares
• Windows 7 operating system
• Openoffice v5
• STARFACE Callmanager fr UCC-Client
• Client Software for Iphone
• Microsoft Office 2010
• Texmaker 4.4.1
• Ganttproject-2.7-r1891
• Microsoft excel 2010 . . . . . .
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B Hardware
• Avaya 9600 IP Phone
• Dect Avaya 590V5
• Gateway from Norton (NR2005)
• CISCO BE6000 Server
• CISCO 7925X IP Phone
• IP PHONE 9608G GRY
• Gigaset N720
• CISCO UNIFIED IP PHONE 6941
• CISCO 7925G DESK TOP CHARGER
• CISCO UC 2 Port Analog Telephone Adapter . . . . . .
C Additional Resource
• Smartsheet for Gantt Chart
• The Fast Forward MBA in Project Management (Fourth Edition) [Ebook]
• Introduction to VOIP [Ebook] . . . . . .
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