How To Analyze The Performance Of Voip Internet Telephony Based On Quality Of Service (Qos)

Transcription

1 looooo 3(p S 36 MARA University of Technology AN ANALYSIS OF VOIP INTERNET TELEPHONY PERFORMANCE BASED ON QUALITY OF SERVICE (QoS) NORFADZILAH BINTIABD MANAP Thesis submitted in fulfilment of the requirements for BSc (Hons) Data Communication And Networking Faculty of Information Technology And Quantitative Science April 2005

2 >'"\ AN ANALYSIS OF VOIP INTERNET TELEPHONY PERFORMANCE BASED ON QUALITY OF SERVICE (QoS) By NORFADZILAH BINTI ABD MANAP A project paper submitted to FACULTY OF INFORMATION TECHNOLOGY AND QUANTITATIVE SCIENCES MARA UNIVERSITY OF TECHNOLOGY In partial fulfillment of requirement for the BACHELOR OF SCIENCE (Hons.) IN DATA COMMUNICATION AND NETWORKING Major Area: Network Management Approved by the Examining Committee: En. Shamsul Jamel Bin Eiias Project Supervisor Cik Faridah binti Sappar Examiner MARA UNIVERSITY OF TECHNOLOGY SHAH ALAM, SELANGOR APRIL 2005

3 CERTIFICATION OF ORIGINALITY This is to certify that I am responsible for the work submitted in this project that the originality work is my own except as specified in the references and acknowledgement and that the original work contained herein have not been taken or done by unspecified sources or persons. NORFADZILAH BINTIABD MANAP APRIL

4 ACKNOWLEDGEMENT Assalamualaikum w.b.t. "In the name of Allah, the Most Gracious and Most Merciful" First and foremost, I thanked Allah the Al-Mighty for I am blessed to complete this research project in time. Special thanks to En. Shamsul Jamel B Elias, my very helpful and supportive supervisor for his supervision, comments, idea and guidelines to come up with this research project. I would like to thanks to Dr. Saadiah Yahya and En. Adzhar Kadir, for the explanation and guidelines given in order to carried out this project successfully. Your kindness, advice, comment, guidance and explanation throughout this time of research were a lot of help in completing this final year project paper. I also would like to extend the appreciation to all my friends who always been there to give their opinion and suggestion. To my beloved family, I would like to forward my obliged to them for their continuous support during my study period, their patience and benevolence. Lastly, I would like to thanks again to everyone who has contribute to the completion of this research project. Your kindness and cooperation in completion of this final year project paper is much appreciated. Wassalam. -HI

5 ABSTRACT This project examines the performance of VoIP Internet Telephony based on QoS parameters through Direct and Indirect LAN. The performance is analyzed by using Actema PVA-1000, NetQuality and AnalogX-NetStat Live. Actema PVA-1000 is an analysis tool for Indirect LAN while NetQuality is used for analysis in Direct LAN. Both tools will use the same QoS parameters which are packet loss, jitter and voice quality. Then, AnalogX-Netstat Live is used for analysis to throughput and bandwidth for Direct and Indirect LAN. To find out the reason VoIP is not inadequate for integrated of voice and data transmission, this research project is conducted with the main goal is to analyze the performance of VoIP Internet Telephony based on the Quality of Service (QoS) parameters. Analysis to the performance of VoIP through the QuaUty of Service (QoS) consists of two phases. The first phase is analyzing VoIP performance on Direct and Indirect LAN. The second and the only phase is to make comparison to the performance between thefindingsof the first phase. Outcomes of the analysis had found that, both source and destination addresses either in Direct or Indirect LAN faced degradation of voice quality in the network. But the quality is least affected at the source address which is initiated the conversations rather than at the destination address. Moreover, VoIP performance in Indirect LAN is suffered to degradation of voice quality compare to Direct LAN. IV-

6 TABLES OF CONTENTS CERTIFICATION OF ORIGINALITY ACKNOELEDGEMENT ABSTRACT TABLE OF CONTENTS LIST OF GRAPHS LIST OF TABLES LIST OF FIGURES ii iii iv v ix x xi CHAPTER 1 INTRODUCTION 1.1 PROJECT INTRODUCTION PROJECT BACKGROUND PROBLEM STATEMENT PROJECT OBJECTIVE PROJECT SCOPE PROJECT SIGNIFICANCE SUMMARY ORGANIZATION OF THE RESEARCH 5 CHAPTER 2 LITERATURE RIVIEW 2.1 VOICE OVER INTERNET PROTOCOL (VOIP) The benefits of Voice over IP INTERNET TELEPHONY QUALITY OF SERVICE (QOS) Putting QoS into VoIP Challenges of QoS in VoIP network 11

7 2.3.3 Quality of Service Issues in ff Networks TYPES OF VOIP CONNECTIONS TESTED Direct LAN Indirect LAN TYPES OF QOS PARAMETER Packet loss Jitter Voice Quality Throughput Bandwidth SIMILAR STUDIES Peribit Boosts VoIP Performance For Health Care Call Centers Peribit Boosts VoIP Performance For Health Care Call Centers Voice over ff We are VoIP Making VoIP Better New Monitoring, Testing Tools Help 18 Assure the Quality of IP Voice Using Overlay Networks to Improve VoIP Quality Sound Quality Evaluation: Acoustic Echo Ensuring VoIP Success THE SIMILARITY BETWEEN OUR PROJECT AND THOSE 22 ABOVE 2.8 THE DIFFERENCES BETWEEN OUR PROJECT AND OTHERS SUMMARY 22 VI

8 CHAPTERS METHODOLOGY 3.1 RESEARCH APPROACH AND METHODOLOGY PLANNING Data Collection Software and Hardware Requirement Software Requirement Hardware Requirement IMPLEMENTATION Implement the proj ect Software and Hardware Installation and Configuration Testing Testing Point ANALYSIS Analyzed the performance Identify the conclusion SUMMARY 32 CHAPTER 4 RESULTS AND FINDINGS 4.1 VoIP INTERNET TELEPHONY PERFORMANCE ANALYSIS VoIP performance analysis for Indirect LAN VoIP performance analysis on Packet Loss VoIP performance analysis on Jitter VoIP performance analysis on Voice Quality VoIP performance analysis on Throughput and Bandwidth 44 vu

9 4.1.2 VoIP performance analysis for Direct LAN VoIP performance analysis on Packet Loss VoIP performance analysis on Jitter VoIP performance analysis on Voice Quality VoIP performance analysis on Throughput and Bandwidth COMPARISON TO VOIP PERFORMANCE BETWEEN DIRECT 51 AND INDIRECT LAN Comparison to the packet loss Comparison to the jitter Comparison to the Voice quality Comparison to the throughput and bandwidth SUMMARY 54 CHAPTER 5 CONCLUSIONS AND RECOMMENDATIONS 5.1 CONCLUSIONS RECOMMENDATIONS 57 REFERENCES 58 APPENDICES 60 - viii

10 LIST OF GRAPHS Graph 4.1 Packet loss for Indirect LAN 37 Graph 4.2 Jitter for Indirect LAN 39 Graph 4.3 Packet loss for Direct LAN 47 Graph 4.4 Jitter in Direct LAN 48 IX-

11 LIST OF TABLES Table 4.1 MOS Score 42 Table 4.2 R-Factor Value Range 42 Table 4.3 Value of MOS Score and R Factors in Indirect LAN 43 -X

12 LIST OF FIGURES Figure 3.1 SDLC Phases 23 Figure 3.2 Project Methodology Phases Diagram 25 Figure 3.3 Sounds and Audio Devices Properties 29 Figure 3.4 Volume Control 29 Figure 4.1 ActemaPVA-1000 Capture Agent 34 Figure 4.2 Capture in Progress 35 Figure 4.3 Indirect LAN 36 Figure 4.4 Voice Quality for Indirect LAN 41 Figure 4.5 Throughput and Bandwidth for Indirect LAN 44 Figure 4.6 Direct LAN 46 Figure 4.7 NetQuality Results 49 Figure 4.8 Throughput and Bandwidth for Direct LAN 50 XI-

13 CHAPTER 1 INTRODUCTION 1.1 PROJECT INTRODUCTION VoIP (Voice over Internet Protocol) is a technology used in IP telephony for a set of facilities for managing the delivery of voice information using the Internet Protocol (IP). The basic steps involved in originating and internet telephone call are conversion of the analog voice signal to digital format and compression or translation of the signal into Internet Protocol (IP) packets for transmission over internet; the process is reversed at the receiving end. Internet Telephony, also called IP Telephony, is the technology that makes it possible to have a voice conversation over the Internet or a dedicated Internet Protocol (IP) network instead of dedicated voice transmission lines. This allows the elimination of circuit switching and the associated waste of bandwidth. Instead, packet switching is used, where IP packets with voice data are sent over the network only when data needs to be sent, i.e., when a caller is talking. Nowadays, VoIP has been a front runner for companies looking to take advantage of IP. There are cost benefits, however with VoLP there is challenges to the performance. The biggest challenge in transitioning from traditional circuit-switched voice systems to the new, more economical voice over IP packet-switched technologies, is obtaining adequate Quality of Service (QoS) over the network. QoS in a network must be adept of; prioritizing fraffic types; interpreting traffic types (applications running over IP); and then conveying them over the network so that QoS requirements can be met.

14 What is QoS refers to? - QoS or Quality of Service is the capability built into the network to guarantee that information traverses the network in a timely manner. Most existing data networks were designed for bursty applications that are delayinsensitive, meaning that if a data packet arrives within a reasonable amount of time, both the application and the user are satisfied. Voice data, on the other hand, are very sensitive to delay; if a packet arrives more than approximately 200 milliseconds (ms) after it is transmitted, the packet is worthless as a carrier of real-time communication because it will arrive too late to be used in the conversation. Consequently, networks carrying IP voice must be designed and configured properly to ensure that real-time packets traverse the network efficiently. These scenarios will effects the performance of VoIP since voice and data are integrated in the same network. 1.2 PROJECT BACKGROUND The conditions of VoIP which is enabled voice and data integrated in the same transmission medium over networks has leads to the ineffectiveness of the VoIP performance. To overcome this situation an analysis to VoIP performance is measured to identify the source of the problems. The analysis will be measured based on VoIP Quality of Service (QoS) parameters which are packet loss; voice quality; jitter; throughput and bandwidth. Those parameters is then will be analysis using three(3) software analyzers which are Actema PVA-1000, NetQuality and AnalogX-NetStat Live. Actema PVA-1000 software analyzer contains capture agent which responsibility is to capture voice data in real time transmission. While the analyzer will then analysis the captured data in the offline mode. This analyzer will analyze voice data for transmissions in Indirect LAN and will measured VoIP QoS parameters which are packet loss, jitter and voice quality. 2-

15 Next, NetQuality is network performance-verification and diagnostic tool used for analysis of VoIP network in real time transmission. This tool will be used to analyze voice data in direct LAN. The QoS parameters that will be evaluated by this tool are the value of packet loss, jitter and also the voice quality. And lastly AnalogX-NetStat Live, used to monitor VoIP throughput and bandwidth. This tool will monitor internet connection status and system performance in real time transmissions. 1.3 PROBLEM STATEMENT There are many factors that will cause to the degradation of VoIP performance and quality in the network. Some of the factors are packet loss, jitter and voice quality. In addition, throughput and bandwidth in the network is also taking into consideration when we want to determined the quality of service in the VoIP network. Everyone especially end users wants the option of having high-quality internet calls with high availability at low cost. Voice over IP networks promise this, but are still far from delivering fully on that promise. Jitter and packet drops that can be tolerated in an IP data network are key contributors to poor quality in VoIP. Users do not know what the causes are and why they are facing the problems. Addition, they also do not know how to measure and overcome those situations. Consequently, persistent quality problems will lead to user's dissatisfaction. It is essential to pro-actively monitor the quahty of every call made in a network in order that quality issues can be detected and resolved immediately. So, before the problem can be fixing, we need to identify and find out the caused. Therefore this project is conducted with the main purpose is to identify and determine which QoS parameter is affected VoIP performance during the conversations in the network. Analysis is measured and once the caused is identified a specific task can be taken to overcome the situation. -3

16 1.4 PROJECT OBJECTIVE This project is done regarding to the main objectives. It is important to state the objectives of the project clearly; it is to ensure the project is kept on track. Analysis Voice over Internet protocol (VoIP) Internet Telephony performance based on QoS parameters are divided into three (3) objectives. To implement VoIP Internet Telephony. To analyze VoIP performance in Direct an in Indirect LAN based on the Quality of Service (QoS) parameters. To make comparison to the performance based on second objective between Direct and Indirect LAN. 1.5 PROJECT SCOPE Because there are constraints to be considered while conducting this project thus, to make this project work and more specifically clear, it will be conducted on the following project scope. To focus on the communications between end users by using Internet Telephony application ~ Skype. To analyze VoIP performance based on QoS parameters which are packet loss, voice quality, jitter, throughput and bandwidth through Direct and Indirect LAN. 1.6 PROJECT SIGNIFICANCE It is hoped that when this project paper is completed, it is will be valuable additional information to VoIP Intemet Telephony users to understand why they are obtaining inadequate voice quality. Therefore, it is hoped can reveal why VoIP performance degradation occurs. -4

17 Then it is also hoped that, this project paper will help users that wants to troubleshoot their own conversations overcome the causes through this information's. As a conclusion, this project paper can give benefit to peoples by providing information's about VoIP performance in depth. Besides that, it is will easier users to understand each type of the QoS parameters that are affected in VoIP network and can make this project paper as reference for their study. 1.7 SUMMARY Nowadays, Voice over Internet Protocol (VoIP) or Internet Telephony technologies are common to the public. Due to the increasing of the popularity of this technology that provides no phone call bills to users, has caused the increasing number of conversations occurs in internet. Since transmissions of communications in network are integrated with various voice and data it is for surely contributes to the VoIP performance degradation. There are three(3) main objectives in this research project. Which is first to implement VoEP Internet Telephony, second, to analyze VoIP performance in Direct and in Indirect LAN based on the QoS parameters evaluations, packet loss, voice quality, jitter, throughput and bandwidth and lastly to make comparison to the performance between Direct and Indirect LAN. 1.8 ORGANIZATION OF THE RESEARCH This is the detailed about the thesis organization to make it more efficient and a guide to do the research project. Through this stage, we should obtain clear view of overall of the thesis and problems about this project.

18 Chapter 1: Introduction In this chapter, we had been discussed about the overall of the research in general. It contains the overviews of the problem, objectives, scope and significance of the project. Chapter 2: Literature Reviews This chapter will discuss about literature review that are related to the analysis of VoIP Internet Telephony based on the QoS parameters. The definition of the VoIP Internet Telephony is clearly defined. The type of the QoS parameters are defined and described one by one. We also state some similar studies to help gives an idea to start and organize this project. Chapter 3: Methodology In this chapter, we will explain the type of methodology that will be used. This project is based on System Development Life Cycle (SDLC). The process is started from planning, implementing and analysis. All method that is used determined the way on how we perform this project orderly to achieve the project objectives. Chapter 4: Finding and Results This chapter will focus on the findings of the analysis that had been done. The analysis to VoIP performance that has been performed and accomplish is discuss to gather the results and the results will shown comparison to VoIP performance between Direct and Indirect LAN. 6-

19 Chapter 5: Conclusion and Recommendation This chapter is the last topic for the project that has been done. It will summarize the overall of the project and will provide the conclusion to finalize the project. Recommendation is suggest for new project to others in future. -7

20 CHAPTER 2 LITERATURE REVIEW INTRODUCTION This chapter will discuss about the review that had been made to understand the concept of the research. From the literatures that are reviewed, we identified the meaning of Voice over Internet Protocol (VoIP), Internet Telephony and Quality of Service (QoS) in VoIP network. The type of QoS parameters that are affected and the tools that are used is identified and discuss. So, this chapter will review some similar studies, the description of the problem, overview different approaches made by previous people and make comparison between our project and those similar studies. 2.1 VOICE OVER INTERNET PROTOCOL (VOIP) Voice delivered using the IP. It is a term used in IP TELEPHONY for a set of facilities for managing the delivery of voice information using the IP. In general, this means sending voice information in digital form in discrete packets rather than in the traditional circuit-committed protocols of the public Switched telephone network (PSTN), (wvvw.247access.co.za/pap/glossarv.html). 2. L1 The benefits of Voice over IP According to Darlington, Roger (2004), there are many benefits of VoIP firstly, and most obviously, there are significant financial savings on running the network itself One infi-astructure carrying both data and voice, provided by one supplier, can be managed, maintained and upgraded much more efficiently than two separate networks for voice and data. Secondly, and more importantly, while each network has its own value, that value is maximised when the two systems are consolidated. Computer 8-

21 applications and communications technologies can be intelligently linked to streamline the working environment. Thirdly, VoIP allows organisations to integrate their telephone, fax, and other applications to capitalise on the benefits of unified messaging. Such a system can eradicate unnecessary interruptions while ensuring individuals always receive information in the most convenient format wherever they are in the world. Fourthly, the system can be used to support flexible working practices, whereby members of staff work from home or in dispersed, 'virtual' teams. Using the VoIP network, team members can see when their colleagues are logged on to the Lv^N or using the telephone. VoIP offers improved bandwidth capabilities and makes video-conferencing a viable and costeffective option for discussions between dispersed team workers. Fifthly, VoIP technology can contribute to an effective knowledge management strategy. The larger the organisation is, the more information that must be shared, so an efficient communications system is particularly important. The VoIP network provides individuals with the opportunity to tap into colleagues' areas of specialism, allowing them to search for experts according to specific criteria. Sixthly, an organisation can also use VoIP to enhance relationships with its customers. For example, converged call centres, or 'IP contact centres', allow agents to answer all customer enquiry mediums, including telephone, , fax, web call back, web chat and instant messaging. Customers appreciate the flexibility of interacting with an organisation that can handle feedback from a range of different sources, and are even more inclined to do business with those who can offer an integrated response. 9-

22 2.2 INTERNET TELEPHONY IP Telephony, also called 'Internet telephony', is the technology that makes it possible to have a telephone conversation over the Internet or a dedicated Internet Protocol (IP) network instead of dedicated voice transmission lines. This allows the elimination of circuit switching and the associated waste of bandwidth. Instead, packet switching is used, where IP packets with voice data are sent over the network only when data needs to be sent, i.e., when a caller is talking, (en.wikipedia.org/wikia^oip) 2.3 QUALITY OF SERVICE (QOS) According to Quality of Service is a performance specification of a communications channel or system or the rating of telephone communications quality in which listeners judge transmissions by qualifiers, such as excellent, good, fair, poor, or unsatisfactory. A general term that incorporates bandwidth, latency, and jitter to describe a network's ability to customize the treatment of specific classes of data. For example, QoS can be used to prioritize voice and video transmissions over Webbrowsing traffic. Advanced networks can offer greater control over how data traffic is classified into classes and greater flexibility as to how the treatment of that traffic is differentiated fi-om other traffic Putting QoS into VoIP According to Horacio Miranda de Oliveira (2000), VoIP has some important limitations, such as the lack of quality of service (QoS) guarantees and accessibility of the service. QoS is an important differentiation element for network operators as well as a metric for regulators. For VoIP networks, the QoS evaluation is an important issue mainly because of the 'best effort' (lowquauty) policy of the internet. 10

23 For that reason, operators providing a telephony service based on IP technology have to set the customer's mind at rest on the level of service quality. Furthermore, the multiplication of networks, interconnections and services tends to increase the difficulty of end-to-end QoS determination Challenges of QoS in VoIP network QoS in VoIP networks represents a major challenge, not so much during the predictable processes of compressing the voice streams and splitting them into packets, which are mathematically predictable; but the real challenge is sharing the connectionless transmission media with other users in a predictable and quantifiable way. As soon as voice and/or video traffic reaches the IP network, it must compete with traffic, database applications and file transfers from the internet as well as business traffic from private-to-public IP networks. Nevertheless, building networks that can provide the necessary bandwidth and guaranteed delay as well as providing QoS management are important for customer satisfaction. Another real problem of VoIP is that there are too many competing standards that potentially could create havoc and prevent the development of seamless, high-performance networks. For these reasons, the only way to provide QoS guarantees to customers is to manage globally the network's QoS. (Horacio Miranda de Oliveira, 2000) Quality of Service Issues in IP Networks The advantages of reduced cost and bandwidth savings of carrying voice over data networks are associated with some Quality of Service (QoS) issues unique to packet networks. Delivering quauty voice signals from one point to another cannot be considered successful unless the quality of the delivered signal satisfies the recipient. Providing a level of quality that at least equals the PSTN (this is usually referred to as "toll quality voice") is viewed as a -11-

24 basic requirement. Although QoS usually refers to the fidelity of the transmitted voice and facsimile document it can also be applied to network availability, telephone feature availability, and scalability. Many factors have been identified that play a big role in determining the quality of service. They are as follows: Jitter (Delay Variability) Jitter is the variation in inter-packet arrival time as introduced by the variable transmission delay over the network. Removing jitter requires collecting packets and holding them long enough to allow the slowest packets to arrive in time to be played in the correct sequence, which in turn causes additional delay. The conflicting goals of minimizing delay and removing jitter has led to the development of various schemes to adapt the jitter buffer size to match the time varying requirements of network jitter removal. Packet Loss IP networks cannot provide a guarantee that packets will be delivered at all, much less in order. Packets will be dropped under peak loads and during periods of network congestion. But due to the time sensitivity of voice transmissions, however the normal TCP- based retransmission schemes are not suitable. Approaches that compensate for packet loss have to be developed to overcome this problem. Bandwidth Availability Bandwidth is the portion of the network that is available to an application to transfer information on the network. The level of reliability and sound quality that is acceptable among users has not yet been reached and this is primarily because of bandwidth limitations and this also leads to packet 12-