<p>At the moment the demand for IP Telephony is increasing because of its scalability and efficient use of bandwidth. The main issues are security and quality of voice in IP Telephony .The study comprises previous research papers and, on the bases of those papers, comparison is made between two security techniques, IPSec VPN and MPLS VPN. The goal behind this study is to build an IP Telephony setup, with security for private branch network, which is an ISP. IP Telephony networks are currently facing issues regarding security and competent packet switching. </p><p>The comparison further describes that MPLS VPN technique is more scalable and efficient than IPSec VPN, which has been approved in implementation. In the implementation, one centralized call manager is configured to establish calls between different sites. To secure traffic over the internet which travels from one site to another other site, MPLS VPN is configured in MPLS domain. In order to increase the performance of IP Telephony, quality of service (QoS) is implemented. QoS provides thriving outcomes and it is also practically implemented in the lab. QoS enhances the flow of data by prioritizing the voice packets. At the end, it is concluded that MPLS VPN is more efficient and scalable than IPSec VPN, and shows better results, while completely supporting QoS.</p>

At the moment the demand for IP Telephony is increasing because of its scalability and efficient use of bandwidth. The main issues are security and quality of voice in IP Telephony .The study comprises previous research papers and, on the bases of those papers, comparison is made between two security techniques, IPSec VPN and MPLS VPN. The goal behind this study is to build an IP Telephony setup, with security for private branch network, which is an ISP. IP Telephony networks are currently facing issues regarding security and competent packet switching. The comparison further describes that MPLS VPN technique is more scalable and efficient than IPSec VPN, which has been approved in implementation. In the implementation, one centralized call manager is configured to establish calls between different sites. To secure traffic over the internet which travels from one site to another other site, MPLS VPN is configured in MPLS domain. In order to increase the performance of IP Telephony, quality of service (QoS) is implemented. QoS provides thriving outcomes and it is also practically implemented in the lab. QoS enhances the flow of data by prioritizing the voice packets. At the end, it is concluded that MPLS VPN is more efficient and scalable than IPSec VPN, and shows better results, while completely supporting QoS.

The aim of this diploma thesis is to get accustomed with the SIP protocol and with the problematics of attacks targeting this protocol, with the emphasis on DoS and DDoS attacks. The thesis focuses on detailed classification of the attacks, possibilities and forms of generation of the attacks and methodics of defense against them. The attacks of the flood type are especially stressed because they are easily generated and the SIP components are very prone to these attacks. Prototype implementations of the most important ideas concerning attack generation and protection against these attacks are also part of this thesis. Practical tests of the implementations performed in a simulated SIP environment are also included. 1

The aim of this Masters Thesis project is to give the Swedish National Post and Telecom Agency, Post- och Telestyrelsen (PTS), an updated view on I P Telephony relative to the Swedish consumer market. The basic questions were raised by PTS and the focus is on the relevant topics from the agency’s point of view. PTS is primarily interested in understanding what state IP Telephony is in and furthermore what IP Telephony can be used for in practice. What are the possibilities of different implementations and what will be their advantages and disadvantages? Despite being on the scene for many years, IP Telephony is now on the verge of a break through. With the creation of gateways between IP and PSTN, various IP Telephony devices, and with the introduction of SIP (described in RFC2543) as a standard signalling protocol, perhaps today, IP Telephony has a significant potential on the consumer market. Many argue that 2003 will be the year that IP Telephony blossoms. The fact that anyone can be their own operator, the role of the traditional operator versus the new operators, the separation of content and signalling transmission, as well as the efficient use of bandwidth are some of the topics covered in this report.&lt;/p&gt; Due to the introduction of The Electronic Communications Act that comes into effect the 25th of July 2003, replacing The Telecommunications Act and The Radiocommunications Act, much of the focus in this report lies on regulatory issues. However, in order to get an insight in to the regulatory issues it is important to understand the underlying technology of IP Telephony as well as areas such as security, robustness, privacy, and emergency calls. Through a market analysis, an updated overview of the market for IP Telephony will be given, along with plausible future scenarios. This report will provide the reader with answers not by focusing on the theoretical details of the technology itself, but rather in terms of it’s practical use and limitations. / Syftet med denna rapport är att ge Post- och Telestyrelsen (PTS) en uppdaterad bild av den svenska IP-telefonimarknaden för privatpersoner. Då examensarbetet utfördes för PTS togs de grundläggande frågeställningarna fram av myndigheten och fokus för examensarbetet lades således på ämnen relevanta för PTS. Trots att IP-telefoni har varit på tapeten i flera år, har tekniken ännu inte haft sitt genombrott på privatmarknaden. Existensen av slussar mellan IP och PSTN, samt utvecklingen av IP-telefoniutrustning och standardiserade protokoll (såsom SIP beskriven i RFC2543), har givit IP-telefoni förutsättningen att ta en signifikant roll på den svenska privatmarknaden. Många anser att 2003 är året då IP-telefoni kommer att ha sitt genombrott. Utvecklingen och ändringen av den traditionella operatörsrollen, separationen av signaltrafik och samtalstrafik samt den effektiva och variabla användningen av bandbredd, är några av de faktorer som ger upphov till spännande frågeställningar. Introduktionen av lagen för elektronisk kommunikation som träder i kraft den 25 Juli 2003, och ersätter både telelagen och lagen om radiokommunikation, har gjort att fokus till stor del riktas på de regulativa frågorna inom området. För att sätta sig in i dessa regulativa frågor krävs dock god insikt i tekniken bakom IP-telefoni samt förståelse i områden såsom säkerhet, robusthet, QoS och nödsamtal. En marknadsanalys bidrar med en uppdaterad bild av marknaden för IP-telefoni samt möjliga framtidscenarion. Rapporten förser läsaren med svar genom att fokusera på teknikens praktiska användning och begränsningar snarare än att fokusera på de teoretiska detaljerna.

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.

Internet Protocol Telephony (IPT), also known as Voice over Internet Protocol (VoIP), has evolved from a niche technology to one that is adopted fairly well in developed countries. The aim of this research report was to determine whether IPT will also be a success in the Republic of South Africa, which is one of many developing countries. The technology was analysed and it was found that cost reduction, increased productivity and enhanced applications were the most valuable benefits the technology could offer. Particular interesting impediments of the technology were discovered and it was found that there existed both hard issues like security and quality problems, as well as softer issues like internal politics, that could hinder the global success of the technology. The adoption rate of South Africa was compared to that of industrial countries and it was found that South African organisations overall posed a wait-and-see attitude towards IPT. Various implementation models were discussed and it was found that a hybrid approach would be the most viable option for local organisations. The South African environment were analysed and it was discovered that the biggest obstacle for success in South Africa was the regulatory environment. But it was also found that the environment would soon change and that competitors, including Black Economic Empowerment companies, should use the opportunities available. Social factors like HIV/AIDS and theft as well as economic factors like the exchange rate could hamper the competitiveness of local companies using IPT. IPT technology can only be a success in South Africa if it is intensely supported by Government, implemented in the correct manner and adopted aggressively by the local market. / Dissertation (MBA)--University of Pretoria, 2006. / Graduate School of Management / unrestricted

The aim of this Masters Thesis is to propose to SYSteam Nät AB, a local Internet Service Provider (ISP) in Uppsala, Sweden, how to implement IP telephony in their existing ITinfrastructure as a service to their customers. Thus the perspective of the thesis will be that of a local Internet Service Provider. Three general areas are covered in the thesis: Market and Business Model, Technology, and Economics. Important issues for SYSteam Nät AB as an established local broadband Internet Service Provider are to both retain present customers and to attract new customers. Some believe that offering value added services such as IP telephony could do this. Implementation of IP telephony can be done in different ways to fulfil SYSteam Nät’s requirements. The analysis leads to a proposal of how SYSteam Nät could implement IP telephony. This involves many multi-faceted business, technical, and financial issues; each aspect is examined in this thesis. / Avsikten med detta examensarbete är att komma med ett förslag till SYSteam Nät AB, en lokal Internetleverantör i Uppsala, om hur de, som en service till sina kunder, kan implementera IP telefoni i sin existerande IT-infrastruktur. Detta betyder att jag behandlar frågeställningen med en Internetleverantörs perspektiv.Tre huvudområden behandlas i examensarbetet: Marknad och Affärsmodell, Teknik och Ekonomi. Som en etablerad lokal leverantör av Internet via bredband är det viktigt för SYSteam Nät AB att både behålla nuvarande kunder och att attrahera nya kunder. En del tror att man skulle kunna åstadkomma detta genom att erbjuda värdehöjande tjänster som IP telefoni. Implementering av IP telefoni, som svarar mot SYSteam Näts krav, kan utföras på olika sätt. Analysen, som leder till ett förslag hur SYSteam Nät skulle kunna implementera IP telefoni, involverar många mångfasetterade frågeställningar av affärs-, teknisk- och ekonomisk natur. Var och en av dessa aspekter behandlas i rapporten.

Master's Thesis is engaged on possibilities connect SIP server to telephone network on FIT. The main reason is that employees can call to university, when they are out of faculty. For resolution we will use SIP server Asterisk, which will be serving as authorization server for users. Next Asterisk will ensure transmission numbers to SIP address with ENUM. In the practical part we will verify the functionality.

<p>In today's world, more and more phone calls are made over IP. This results in an increasing demand for scalable IP telephony equipment.</p><p>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.</p><p>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.</p><p>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.</p><p>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.</p>

<p>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. </p><p>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. </p><p>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.</p>