Secure VoIP Performance Measurement

This project presents a mechanism for instrumentation of secure VoIP calls. The experiments were run under different network conditions and security systems. VoIP services such as Google Talk, Express Talk and Skype were under test. The project allowed analysis of the voice quality of the VoIP services based on the Mean Opinion Score (MOS) values generated by Perceptual valuation of Speech Quality (PESQ). The quality of the audio streams produced were subjected to end-to-end delay, jitter, packet loss and extra processing in the networking hardware and end devices due to Internetworking Layer security or Transport Layer security implementations. The MOS values were mapped to Perceptual Evaluation of Speech Quality for wideband (PESQ-WB) scores. From these PESQ-WB scores, the graphs of the mean of 10 runs and box and whisker plots for each parameter were drawn. Analysis on the graphs was performed in order to deduce the quality of each VoIP service. The E-model was used to predict the network readiness and Common vulnerability Scoring System (CVSS) was used to predict the network vulnerabilities. The project also provided the mechanism to measure the throughput for each test case. The overall performance of each VoIP service was determined by PESQ-WB scores, CVSS scores and the throughput. The experiment demonstrated the relationship among VoIP performance, VoIP security and VoIP service type. The experiment also suggested that, when compared to an unsecure IPIP tunnel, Internetworking Layer security like IPSec ESP or Transport Layer security like OpenVPN TLS would improve a VoIP security by reducing the vulnerabilities of the media part of the VoIP signal. Morever, adding a security layer has little impact on the VoIP voice quality

Improving ICE Service Selection in a P2P System using the Gradient Topology

GS

Analyzing of MOS and Codec Selection for Voice over IP Technology

In this research, we propose an architectural solution to implement the voice over IP (VoIP) service in campus environment network. Voice over IP (VoIP) technology has become a discussion issue for this time being. Today, the deployment of this technology on an organization truly can give a great financial benefit over traditional telephony. Therefore, this study is to analyze the VoIP Codec selection and investigate the Mean Opinion Score (MOS) performance areas evolved with the quality of service delivered by soft phone and IP phone. This study focuses on quality of voice prediction such as i) accuracy of MOS between automated system and human perception and ii) different types of codec performance measurement via human perception using MOS technique. In this study, network management system (NMS) is used to monitor and capture the performance of VoIP in campus environment. In addition, the most apparent of implementing soft phone and IP phone in campus environment is to define the best codec selection that can be used in operational environment. Based on the finding result, the MOS measurement through automated and manual system is able to predict and evaluate VoIP performance. In addition, based on manual MOS measurement, VoIP conversations over LAN contribute more reliability and availability performance compare to WAN.Comment: 14 pages, exposed on 5th International Conference "Actualities and Perspectives on Hardware and Software" - APHS2009, Timisoara, Romani

Revenue requirements for mobile operators with ultra-high mobile broadband data traffic growth.

Mobile broadband data access over cellular networks has been established as a major new service in just a few years. The mobile broadband penetration has risen from almost zero to between 10 and 15 per cent in Western European leading markets from 2007 to the end of 2009. More than 75% of network traffic was broadband data in 2009, and the data volumes are growing rapidly. But the revenue generation is the reverse as the average for operators in Europe in 2009 was around 77 per cent of service revenues from voice, 10 per cent from SMS and 13 per cent from other data. Voice and broadband data service are built on two quite different business models. Voice pricing is volume based. Revenue depends linearly on the number of voice minutes. Broadband data service on the other hand is mainly flat fee based even if different levels are being introduced as well as tiers. Revenue is decoupled from traffic and therefore also from operating costs and investment requirements. This is what we define as a revenue gap. Earnings as well as internal financing will suffer from increasing traffic per user unless the flat fee can be raised or changed to volume based, other revenue can be obtained and/or operating costs and investments can be reduced accordingly. Observable trends and common forecasts indicate strong growth of mobile broadband traffic as well as declining revenue from mobile voice in the next five year period. This outlook suggests a prospective revenue gap with weak top-line growth and expanding operating costs and investment requirements. This is not only a profitability and cash flow issue. It may also severely restrict the industry's revenue and profit growth potential if it is handled mainly by cost-cutting. In sections 2 - 4 we describe related work, our contribution, the specific research questions as well as the methodology and its problems. Section 5 is an overview of mobile operators' revenue, its sources and development till today. Section 6 presents trends, developments and published forecasts that may be relevant for the future. Section 7 contains our conclusions. --Mobile broadband,mobile operator revenues,revenue requirements,voice revenues,non-voice revenues

Voice Over Internet Protocol (Voip) Technology As A Global Learning Tool: Information Systems Success And Control Belief Perspectives

Voice over Internet Protocol- (VoIP) enabled online learning service providers struggling with high attrition rates and low customer loyalty issues despite VoIP’s high degree of system fit for online global learning applications. Effective solutions to this prevalent problem rely on the understanding of system quality, information quality, and individual beliefs about the usefulness of this technology. This research aims to provide insights into increasing the loyalty of users to VoIP-enabled global learning programs from the perspectives of information systems (IS) success and control belief. A theoretical model is proposed to integrate seven major constructs of IS success and planned behavior theory. We tested our model using the path analysis of data collected from an experiment where 66 undergraduate students from the USA and Taiwan worked in pairs using Skype to improve their English and intercultural communication skills. Data analysis results showed that information quality and perceived behavioral control are much more important than system quality in increasing satisfaction with the use of Skype. An increase in user satisfaction can lead to an improvement in intercultural communication competence and to increased user loyalty. Theoretical and practical implications are drawn from the findings to conclude this study

Security measures for VoIP application: a state of the art review

Voice over internet protocol (VoIP) is being widely used, while the integration of voice and data provide several opportunities. Lower cost and more flexibility are the main advantages of the VoIP which derived the attention of the enterprises to it. Unfortunately in the other extreme, some security issues may come across with the extensive use of VoIP. The purpose of this review paper is to encourage the VoIP industry to consider the importance of the security matters of their application and to find the gaps by discussing the pros and cons of each application and performing the fair comparison. This article begins by discussing the motivation of security measures in VoIP applications and a list of possible threats such as denial-of-service (DoS), Call Hijacking and Interception. These security issues are the most well known attacks that can be carried out in current VoIP deployment. Next, we discuss about two VoIP applications, which are Skype and GTalk, and their security levels have been measured briefly by highlighting some of the security issues in them. These security measurements are used to perform the comparison between the studied VoIP applications. Finally some methods have been proposed to improve the security in the VoIP applications in future state

VOIP for Telerehabilitation: A Risk Analysis for Privacy, Security and HIPAA Compliance: Part II

In a previous publication the authors developed a privacy and security checklist to evaluate Voice over the Internet Protocol (VoIP) videoconferencing software used between patients and therapists to provide telerehabilitation (TR) therapy.  In this paper, the privacy and security checklist that was previously developed is used to perform a risk analysis of the top ten VoIP videoconferencing software to determine if their policies provide answers to the privacy and security checklist. Sixty percent of the companies claimed they do not listen into video-therapy calls unless maintenance is needed. Only 50% of the companies assessed use some form of encryption, and some did not specify what type of encryption was used. Seventy percent of the companies assessed did not specify any form of auditing on their servers. Statistically significant differences across company websites were found for sharing information outside of the country (p=0.010), encryption (p=0.006), and security evaluation (p=0.005). Healthcare providers considering use of VoIP software for TR services may consider using this privacy and security checklist before deciding to incorporate a VoIP software system for TR.  Other videoconferencing software that is specific for TR with strong encryption, good access controls, and hardware that meets privacy and security standards should be considered for use with TR.Keywords: Voice over the Internet Protocol (VOIP), telerehabilitation, HIPAA, privacy, security, evaluatio

The Bits of Silence : Redundant Traffic in VoIP

Human conversation is characterized by brief pauses and so-called turn-taking behavior between the speakers. In the context of VoIP, this means that there are frequent periods where the microphone captures only background noise – or even silence whenever the microphone is muted. The bits transmitted from such silence periods introduce overhead in terms of data usage, energy consumption, and network infrastructure costs. In this paper, we contribute by shedding light on these costs for VoIP applications. We systematically measure the performance of six popular mobile VoIP applications with controlled human conversation and acoustic setup. Our analysis demonstrates that significant savings can indeed be achievable - with the best performing silence suppression technique being effective on 75% of silent pauses in the conversation in a quiet place. This results in 2-5 times data savings, and 50-90% lower energy consumption compared to the next better alternative. Even then, the effectiveness of silence suppression can be sensitive to the amount of background noise, underlying speech codec, and the device being used. The codec characteristics and performance do not depend on the network type. However, silence suppression makes VoIP traffic network friendly as much as VoLTE traffic. Our results provide new insights into VoIP performance and offer a motivation for further enhancements, such as performance-aware codec selection, that can significantly benefit a wide variety of voice assisted applications, as such intelligent home assistants and other speech codec enabled IoT devices.Peer reviewe

Comparison of different ways to avoid internet traffic interception

Projecte fet en col.laboració amb la Norwegian University of Science and Technology. Department of Telematic EngineeringEnglish: The main objective of this thesis is to analyze and compare different ways to avoid the Internet traffic eavesdropping (carried out both by governments or malicious particulars). The analysis consists on a description of the different protocols and technologies involved in each option as well as the difficulties to implement them and the technical knowledge of the users in order to take profit of them