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.

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. 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? 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. 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. 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. 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. 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. / 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? 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. 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. 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. 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. 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

My master’s thesis is focused on designing and creating communication network, which provides communication between two independent networks through encrypted tunnel. My solution is based on routers formed by older personal computers with FreeBSD like a operating system. Between routers is created static encrypted tunnel by using IPSec protocol. Voice services provides packet oriented exchange Asterisk with support of signaling protocol SIP. This solution can be used eg. for connecting remote branch to headquarters of company and then can branch utilize shrared resources. To headquarters can connect also remote workers from their home. In this case are used SSL certificates to authentication of user. This scenario is very required today.

This diploma thesis is focused on the implementation of the technology VoIP in the remote branch offices of a big company. There are used the current WAN lines, which have been so far used only for transfer of data. Implementation of IP telephony is extending the utilization of those lines and at the same time the costs for running of the telephone services are reduced. There are described the models for proposal and also the proposal for solution of IP telephony for a specific company.

Issue of this diploma thesis is focused on analysis of audio codecs used within IP telephony. Attention of teoretical part is given mostly to audio codecs according to ITU-T recommendations, but also to signaling protocols used here. For practical part of analysis is chosen router Cisco 2821 and IP phones Cisco 7975G. Configuration is done over operating system Cisco IOS. Chosen signaling protocol is SCCP. For analysis itself are chosen 2 analysers – L-580FX and Fluke NetTool. These are used in combination with program Wireshark. Analysed parameters are latency, packet lost, bandwidth, jitter and mean opinion score. Measured values are presented in graphs and tables and they are discussed. Next output of the thesis is laboratory excercise, which deals with analysis of audio codecs.

This master thesis presents, examines, designs, implements, and evaluates with respect to energy efficiency a secure and robust VoIP system. This system utilizes a Session Initiation Protocol (SIP) infrastructure assisted by a cloud service, specifically focusing on small to medium sized enterprises (SME) and homes. This research focuses on using inexpensive, flexible, commodity embedded hardware (specifically a Linksys WRT54GL wireless router for the local site with a customized operating system, specifically DD-WRT). The idea is to reduce the local site's power consumption to very low levels by examining which functions can be done in a cloud service rather than at the local site. The thesis presents the design of a low-power IP telephony system for the local site and the cloud site. A number of different usage scenarios and desirable features are described. The methodology for conducting a set of experiments is defined to perform stress-testing and to evaluate the low- power IP telephony system's design. The experiments concern the overall power consumption of the local site under various configurations, the VPN link's call capacity, the QoS metrics for the VoIP calls, the session request delay (SRD) and the registration request delay (RRD). The results from these experiments show that there is a potential for significant power savings when using the proposed design for an IP telephony system. / Detta examensarbete presenterar, undersöker, utformar, implementerar, och försöker att utvärdera ett säkert och robust VoIP-system med energieffektivitet. Detta system använder en Session Initiation Protocol (SIP)-infrastruktur med hjälp av en molntjänst med särskild inriktning på, små, och medelstora företag (SME) och hemmanvändare. Denna forskning fokuserar att använda en prisvärt, billig, flexibel, med program inbyggd hårdvara (speciellt en Linksys WRT54GL trådlös router för den lokala platsen med ett anpassat operativsystem DD-WRT). Tanken är att minska energiförbrukningen på, den lokala platsen till mycket låga nivåer genom att undersöka vilka funktioner, som kan köras på, ett molntjnst snarare än på, den lokala platsen. Avhandlingen presenterar utformningen av ett IP-telefonisystem på, den lokala platsen med ett lågt strömbehov och på, molntjänsten. Ett antal olika användningsförhållanden och önskvärda egenskaper är beskrivna. Metodiken för att genomföra en rad experiment definieras för att utföra stresstester och för att utvärdera designen av IP-telefonisystem med ett lågt effektbehov. I försöken experimenteras den totala energiförbrukningen av den lokala platsen under olika konfigurationer, VPN-länkens samtalskapacitet, QoS-mätning för VoIP-samtal, Session Request Delay (SRD) och Registration Request Delay (RRD). Resultaten från dessa experiment visar att det finns en potential för betydande energibesparing när du använder den föreslagna designen för en IP-telefoni system.

Approved for public release, distribution is unlimited / Recent advances in information technology communications have brought about increases in bandwidth and processing speeds to encourage the growth of Internet Protocol Telephony (IPT), a method of transmitting voice conversations over data networks. Many organizations are replacing portions of their traditional phone systems to gain the benefits of cost savings and enhanced feature sets through the use of IPT. The Coast Guard has an interest in exploiting this technology, and has taken its first steps by implementing IPT at Headquarters Support Command in Washington D.C. This thesis investigates the successful implementation practices and security policies of commercial, educational, and government organizations in order to create recommendations for IPT security policies and implementation practices relevant to the Coast Guard. It includes the discussion of the public switched telephone network, an overview of IPT, IPT security issues, the safeguards available to counter security threats, the tradeoffs (e.g., voice quality, cost) required to mitigate security risks, and current IPT security policy and implementation guidance. It is supported by the study and analysis of the IPT system at Coast Guard Headquarters. The Coast Guard gains an understanding of the advantages, limitations, and security issues that it will face as it considers further implementation of IPT. / Lieutenant, United States Coast Guard

隨著資訊通訊技術的快速發展，Internet已成為全世界最重要的資料乘載工具，以IP為基礎的多媒體通訊架構，逐漸取代傳統電話的溝通模式，成為企業快速佈署與協同運作的最佳選擇。透過整合通訊系統（Unified Communications, UC）的導入，企業可以將網路電話、視訊會議、電子郵件、即時通訊與行動裝置等通訊系統整合在同一個平台上，以大幅提升企業協同運能力，並有效的提升企業運作效率。 現今企業內部充斥著各種溝通工具，從傳統的電話、傳真到Internet興起後的MSN與Skype，這些工具廣泛的運用在商務運行中，其目的皆為了增加溝通效率並節省溝通成本，但這些雜亂無章的溝通方式若未能有效整合，將衍生許多資訊安全與系統相容性問題。 UC的觀念已在許多國際大型企業中獲得驗證，而台灣這個充滿創造力的科技島，在資通訊運用的腳步必須與世界接軌，妥善運用自身優勢，以確保在這波國際化浪潮中，持續保持競爭優勢。本研究經由個案訪談大型銀行業、電子製造業與顧問服務業，以科技接受模型為架構，分別探討個人、組織、技術、任務與環境等五大構面所組成的外部變數，對於UC系統採用之有用與易用認知影響，找出影響企業採用整合通訊系統的相關因素，以做為未來企業在採用整合通訊系統時之參考。 關鍵字：Unified Communications，UC，IP Phone，整合通訊系統，TAM，科技接受模型，VoIP，網路電話 / Along with the fast development of the information technology technique, combined with the adoption of Internet that made the Internet the most important transmission tool for communications, the IP-based multi-media communication framework has gradually replacing the traditional fixed-line telephone systems and has become the optimum option for the enterprises for their business establishments and their organizational synchronization. By applying the Unified Communications (UC), enterprises are able to integrate their IP Telephony, Video Conference, e-mail, Instant Message and Mobile Communication devices into the same platform; as a result, the systematic integration has greatly advanced the level of synchronization and improved the efficiency of the business operation. The multiple communication equipment being used such as the traditional telephone, fax, MSN and Skype are for the purposes of enhancing the efficiency of communication and reduce costs. However, the information security and compatibility amongst different systems may become problematic if the integration is not being carefully organized. The adoption of UC was proven to be a success by many international enterprises that has integrated it into their business practices. Therefore, Taiwan, with its good reputation of an island of technology and one who is renowned with its creativity, should keep up to speed with the world in adopting the prevalent information technology. We should keep maintaining our competitive advantage that we have developed over the years. This Study was conducted through interviews with large bank, electronic product manufacturer and consulting services company. The research was based on the TAM framework to analyze the five aspects of the external variables namely, individual, organization, technique, mission and environment. In addition, this Study intends to seek a result that will provide an enterprise a future reference about the factors that can influence in making a decision on the feasibility and applicability of adopting the Unified Communications. Key Words: Unified Communications, UC, IP Phone, TAM（Technology Acceptance Model）, VoIP（Voice over Internet Protocol）, IP Telephony

This thesis focuses on enterprise VoIP telephony network security. Introduces brief comparison of old analog and digital voice networks and IP telephone networks with special focus on VoIP system security. The goal of the thesis is to identify the risks of implementation and operation of VoIP technologies in enterprise environment and so thesis brings some conclusion how to minimalize or avoid these risks. First two chapters briefly introduce the development of telephony technologies with differentiation of enterprise telephone network from public telephone networks. Further it describes individual technologies, digitalization of voice, processing the signal and VoIP protocols and components. Third chapter focuses on infrastructure of telephony networks with special interest for architecture of IP telephony and ways of establishing call processing. It describes data flows for further security risk analysis, which this technology came with. Fifth chapter is about enterprise security standards in common and is trying to describe information security management system (ISMS) adopting VoIP technology. Individual security threats and risks are described in sixth chapter, along with known methods how to avoid them. Final parts of thesis concludes of two real situation studies of threats and risks of VoIP technologies implemented in environment of small commercial enterprise and medium size enterprise, in this example represented by University of economics. These chapters conclude theoretical problems shown on practical examples.

<p>It is very probable that VoIP will soon replace the ordinary telephone. Beside all advantages of the digital voice-connection it is linked to the danger of spam on the telephone. A lot of approaches have been developed to solve the problem of VoIP spam. Because some of these solutions are based on access to personal information of its users, a broad discussion about the best and most ethical approach has started.</p><p>This thesis analyzes the users’ point of view towards the VoIP spam problem and the extent of users’ willingness to offer private information in order to avoid VoIP spam. It presents results from a qualitative and a quantitative research as well as approaches for a most realistic- and most promising VoIP solution. These new approaches are based on the results of the research.</p><p>The main points of the results showed that users were not willing to offer private information to companies and that they were not willing to pay any amount of money for VoIP spam solutions. Users held governmental organisations and telephone operators responsible for finding a solution against VoIP spam.</p>