With the Internet expansion, real-time transmission over Internet is becoming a new promising application. Successful real-time communication over IP networks requires reasonably reliable, low delay, low loss date transport. Since Internet is a non-synchronous packet switching network, high load and lack of guarantees on data delivery make real-time communication such as Voice and Video over IP a challenging application to become realistic on the Internet. This thesis work is composed of two parts within real-time voice and video communication: network simulation and measurement on the real Internet. In the network simulation, I investigate the requirement for the network"overprovisioning"in order to reach certain quality-of-service. In the experiments on the real Internet, I simulate real-time transmission with UDP packets along two different traffic routes and analyze the quality-of- service I get in each case. The overall contribution of this work is: To create scenarios to understand the concept of overprovisioning and how it affects the quality-of-service. To develop a mechanism to measure the quality-of-service for real-time traffic provided by the current best-effort network.

In today's world, more and more phone calls are made over IP. This results in an increasing demand for scalable IP telephony equipment. Ingate Systems AB produces firewalls specialized in handling IP telephony. They have an inherent limit in the number of concurrent phone calls that they can handle. This can be a bottleneck at high loads. There is a load balancing solution available in the platform, but it has a number of drawbacks, such as media latency and client capability requirements, limiting its usage. Many companies provide load balancing solutions for SIP. However, it appears few handle all the problematic scenarios that the Ingate firewall does. This master's thesis aims to add load balancing functionality to the Ingate firewall, so that it can handle all types of clients. By splitting the firewall into two completely separate layers - a SIP layer and a firewall layer - the concept of a virtual machine emerges. A machine is no longer restricted to its physical SIP and firewall layers. Instead, virtual machines are used to process calls. They still have SIP and firewall layers, but the layers can reside on different physical machines. This thesis demonstrates the operation of an innovative load balancing implementation. The implementation was evaluated, and using four machines the test setup performed 50% better than the original Ingate platform, while still retaining all functionality -- something that was not possible with the original platform. This surpassed both the company's and my own expectations.

The market for IP telephony has increased over the years, more organizations integrate this technology with their existing networks. The advantages with IP telephony are the possibility to integrate different networks and transfer voice, data and video. However, the technology does not differ from other new technologies when it comes to handling security problems. The risks may increase when voice and data are transferred in the same network. Therefore it is important to elucidate the security aspects for IP networks. This thesis evaluates the technology by performing a comparison between traditional telephony and IP telephony in order to analyze the maintenance and security aspects of these two technologies. The comparison is based on the security services, authentication, integrity, confidentiality, non-repudiation and availability since these are the fundamental security aspects of IP telephony according to the authors. The result of the comparison indicates that IP telephony fulfils the most important security services, i.e. authentication, integrity and confidentiality. The PSTN (Public Switched Telephone Network) is seen as a secure network, because it is closed, e.g. only the operator has access.

Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur Rechnernetze und verteilte Systeme (Fakultaet fuer Informatik) der TU Chemnitz. Workshop-Thema: Infrastruktur der ¨Digitalen Universitaet¨ Der Vortrag zeigt Grundlagen und aktuelle Entwicklungen auf dem Gebiet der IP-Telephony sowie Arbeiten des Autors an der TU Darmstadt zu diesem Gebiet.

An increasing number of people in Sweden are having problems with their hearing ability. The three major tools to aid hearing-impaired and deaf individuals are: hearing aids, special telephony, and alerting systems. Both hearing aids and telephony have seen a huge technical development. Hearing aids have gone from huge ponderous devices to small delicate in-ear devices. Simple text telephones have evolved into total conversation telephones with audio, video, and text all operating in real time. Although smart lamps and other alerting services not specifically made for hearing-impaired individuals do exist, the development of alerting system is unsatisfactory. The gap in technology is a huge problem and integration between modern products and alerting systems is getting harder. This thesis explores how to close this gap. The result of this thesis project is a prototype that provides the missing technological link between an alerting systems and modern smart devices. An eventual product should support all kinds of services, but the prototype is limited to solving the problem of connecting an alerting system to a modern total conversation telephones. The prototype was evaluated and based on the evaluation data a timeline was created. An overall positive response towards the product exists and the timeline had adding more third party services (such as Skype and FaceTime) as a high priority. The complete timeline as well as adding Signal Initiation Protocol support is left as future work. / I Sverige har antalet personer med hörselskada ökat de senaste åren. För att hjälpa de med hörselproblem finns det tre viktiga hjälpmedel: hörapparater, special telefoner och varseblivningssystem. Stora teknologiska framsteg har skett för både hörapparater och special telefoner. Hörapparater har gått från stora otympliga apparater till små nätta anordningar som man har i örat. Enkla texttelefoner är idag komplexa system som stödjer både video, ljud och text i realtid. Även fast smarta lampor och andra varseblivningsprodukter existerar så är utveckling för varseblivning speciellt gjorda hörselskadade och döva undermåliga. Gapet som skapats mellan moderna varseblivningsprodukter och varseblivning som hjälpmedel växer sig allt större. Denna rapport ska undersöka detta gap. Resultatet av detta projekt är en prototyp som tillhandahåller den teknologin som ska länka modern varseblivning och varseblivning som hjälpmedel. Den tänkta produkten kan användas för många olika tjänster men i detta projekt är den begränsad till total konversations telefoner. Prototypen har blivit utvärderad och en tidslinje, baserad på utvädringen, har skapats. Tidslinjen ska beskriva kommande tjänster och enheter som skall kunna användas tillsammans med prototypen. Det visar sig att den skapade prototypen blev positivt mottagen och att tjänster som Skype och Facetime skulle ha hög prioritering på tidslinjen.

Cloud computing has evolved from cutting-edge technology to a best practice for businesses across industries. However, compliance with regulatory mandates and addressing security challenges in the cloud environment remain significant concerns. This thesis aims to explore the compliance, regulatory, and security challenges associated with cloud computing, with a particular focus on the differences in regulatory frameworks between an Asian country (India) and a European country (Sweden). Additionally, the study delves into the forensic investigation challenges in terms of evidence collection in the cloud environment. The research methodology involves studying the available literature on regulatory rules and cloud forensics, conducting surveys with cloud customers, experts, and cloud service provider (CSP) professionals, and proposing possible solutions and recommendations to overcome the identified challenges. By addressing these issues, this research contributes to a comprehensive understanding of the impacts of compliance regulations on cloud and IP Telephony services and the security and forensic investigation challenges in cloud platforms.

IP telephony is defined as the transport of telephony calls over an IP network. IP telephony exploits the integration of voice and data networks. However, enterprises are still reluctant to deploy IP telephony despite the potential increase in productivity and reduction of costs. The principal concerns are: can IP telephony provide the same level of performance in terms of security, reliability, and scalability as traditional telephony? If so, are its proclaimed benefits such as flexibility and mobility cost-effective? The aim of this thesis is to analyze how to deploy IP telephony in large corporations - while providing the necessary security and facilitating mobility. Through the different parts of this thesis, we will analyze the applicable technologies, along with their integration and management. We will focus on the essential requirements for an enterprise of scalability, reliability, flexibility, high-availability, and cost-effectiveness. The massive changes brought about due to the deregulation of telecommunications in nearly all countries, the increasingly global nature of business, and the progressively affordable and power technology underlying information and communication technologies have lead to increasing adoption of IP telephony by residential and commercial users. This thesis will examine these technologies in the context of a very large distributed corporation. / IP telefoni är definierat som transporten av telefon samtal genom ett IP nätverk. IP telefoni utnyttjar integrationen av tal och data nätverk. Dock är affärsföretag fortfarande motsträviga till att införa IP telefoni trots potentiell ökning i produktivitet och minskade kostnader. Huvud bekymren är: kan IP telefoni tillhandahålla samma nivå av prestanda med avseende på säkerhet, tillförlitlighet, och skalbarhet som traditionell telefoni? Och i så fall, är dom proklamerade fördelarna flexibilitet och rörlighet kostnadseffektiva? Målet för detta examensarbete är att analysera hur IP telefoni kan införas i stora affärsföretag - medan samtidigt tillhandahålla nödvändig säkerhet och främja rörlighet. Genom olika delar av detta examensarbete, analyserar vi tillämpliga teknologier, inklusive deras integrering och skötsel. Vi kommer att fokusera på de grundläggande kraven för ett affärsföretag gällande skalbarhet, tillförlitlighet, flexibilitet, hög tillgänglighet, och kostnadseffektivitet. Dom massiva förändringarna frambringade i och med avregleringen av telekommunikation i stort sett alla länder, affärsverksamhetens alltmer globala natur, och de progressivt kostnadseffektiva och kraftfulla underliggande teknologier bakom informations och kommunikations system har lett till ökande adoptering av IP telefoni av både privata och kommersiella användare. Detta examensarbete undersöker relevanta teknologier i samband med mycket stora utbredda affärsföretag. / <p>Exchange student from Centro Politecnico Superior (University of Zaragoza, Spain).</p>

Les services de téléphonie IP automatisent le traitement des stimuli de communication en utilisant des ressources réseaux. Cependant, l'ajout de services rend vulnérable le système de téléphonie car certaines propriétés de fonctionnement des services déployés ne sont pas garanties. Aucune solution de développement de services ne permet de simultanément garantir des propriétés de fonctionnement et d'exploiter des ressources réseaux. Cette thèse propose une approche fondée sur le concept des langages dédiés pour développer des services de communications. Deux nouveaux langages dédiés au domaine des communications ont été développés : SPL et Pantaxou. Le premier sert à router des messages de signalisation tandis que le second, plus généraliste, permet la coordination d'entités communicantes. Dans cette thèse, nous démontrons, grâce à SPL et Pantaxou, que les services de communications peuvent être développés avec un langage de programmation expressif tout en préservant des propriétés critiques du domaine. / IP telephony services use network resources to automate communication stimuli processing. However, deploying services on a telephony system leads to safety issues and programmers need to ensure some safety properties on their services. Several approaches allowing service development have quickly emerged. However, none of them is both expressive and safe. This thesis proposes a new approach that relies on domain-specific languages (DSL) to develop communication services. Two new DSLs have been designed for communication services, namely SPL (Session Processing Language) and Pantaxou. The first one allows to route signaling messages while the second one, more generalist, enables to define coordination logics of communicating entities. In this thesis, we demonstrate thanks to SPL and Pantaxou that communication services could be developed with an expressive programming language that preserves some critical domain properties.

O projeto VoIPFix surgiu da necessidade de uma ferramenta que complementasse as demais existentes no ramo de análise de redes de computadores para telefonia IP. Ele foi construído para ser uma ferramenta de gerenciamento eficiente e exclusiva para VoIP, com funcionalidades necessárias para dar suporte ao profissional de rede de computadores e telefonia IP a observar e diagnosticar problemas de VoIP. / The VoIPFix project arose from the need for a tool to complement similar tools in the analysis of computer networks for IP telephony. It was built to be an efficient and unique management tool for VoIP, with advanced features required to support the computer network and IP telephony professionals to observe and diagnose problems related to VoIP.

<p>På några år har användningen av IP-telefoni inom svenska företag tredubblats och vi börjar nu se ett attitydskifte gentemot en teknik som länge dragits med dåligt rykte på grund av kvalitetsbrister.</p><p>IP-telefoni är ett resultat av att data- och telefonikommunikation vävs samman och att kapaciteten i nätverken ökar. Detta medför att man genom att införa IP-telefoni kan genomföra kostnadsbesparingar och effektivisering. Men tekniken erbjuder även ökad funktionalitet och därmed även mervärde för organisationer som använder IP-telefoni. Inser organisationer detta och utnyttjar man fördelarna med tekniken för att skapa acceptans inom organisationen?</p><p>Syftet är att undersöka vilka faktorer som motiverar en övergång från kretskopplad telefoni till IP-telefoni, och hur man inom en organisation skapar acceptans för den nya tekniken.</p><p>Syftet har uppfyllts genom en kvalitativ studie som byggt på semi-standardiserade intervjuer. Studien genomfördes hos fyra svenska organisationer som implementerat en ”ren” IP-telefonilösning med IP-växel och hårdvarutelefoner.</p><p>Resultatet av studien visar att det är vanligt att utnyttja en större händelse som startskott för implementationen. Detta kan röra sig om en flytt eller en renovering av organisationens lokaler. De främsta orsakerna till att man väljer IP-telefoni har visat sig vara kostnadsbesparingar, effektivisering av nätverksinfrastrukturen samt att man ser tekniken som en investering för framtiden. Det har visat sig att de företag som genomfört en grundlig studie av IP-telefoni som teknik, inledningsvis har identifierat fler fördelar med tekniken.</p><p>Vidare har studien även visat att organisationer upplever ett initialt motstånd till förändringen från anställda och att detta motstånd ofta uppkommer i anknytning till tekniska problem som uppstår i samband med implementationen.</p><p>Det är mycket ovanligt att organisationer har en speciell fas för att skapa acceptans för förändringen, vilket troligtvis beror på att man ser användandet som liknande med traditionell PSTN-telefoni och att resurser istället läggs på att lösa tekniska problem.</p> / <p>Over the last few years there has been a threefold increase in the use of IP telephony within Swedish companies. We are now beginning to see a change in attitude towards a technology that thanks to poor Quality of Service has been struggling with a bad reputation. IP telephony is a result of computer and telephone networks being con-verged, and by doing this, costs can be saved and efficiency boosted. But the technology does also offer increased functionality and thereby added value to the organisations using it. But do organisations realize this, and do they exploit the benefits of the technology in order to create acceptance for it within the organisation?</p><p>The purpose is to examine what the motivating factors are for a transition from PSTN telephony to IP telephony, and also to study how acceptance for the new technology is created within the organisation.</p><p>The purpose has been fulfilled by conducting a qualitative study based on semi-standardized interviews. The study has been conducted at four Swedish organisations that have implemented a "pure" IP telephony solution including IP gateways and IP telephones.</p><p>The result of the study shows that it is common to use a "big event" as a starting block for the implementation. This could be a relocation or the restoration of an office building. The main reason for choosing IP telephony is the fact that convergence cuts costs, boosts efficiency, and that organisations see IP telephony as an investment for the future. We have noticed that organisations that conduct a thorough study of IP telephony have identified more functional advantages with the technology.</p><p>Furthermore, the study has shown that organisations experience initial resistance from users, and that this resistance often arises in connection to technical problems that transpire during the implementation.</p><p>It is rare for organisations to have special phase for creation of acceptance, which most likely is due to the fact that organisations see the use of IP telephony as similar to the use of traditional PSTN telephony, and that resources instead are being placed on solving technical problems</p>