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Voice Service in Integrated Networks
Yeftsifeyeu, Aliaksandr ; Polívka, Michal (referee) ; Škorpil, Vladislav (advisor)
The master’s thesis presents routing protocols, SIP handshake, describes modern VoIP networks and its features. Thesis is primary focused on networks with integrated MPLS. The most known advantages and disadvantages were described of modern network based on such technology. Further, networks and a router with installed Cisco Call Manager Express 7.1 were configured, which is provided by CISCO. For recreating of fully working telephone network IP PBX10 has been used from SMC Networks. For connection between different phones within these integrated networks, SIP trunk was configured on SMC PBX10 as well as on router, which is connecting three configured Cisco IP phones. Each phone has its own number according to the dial plan. For calls from one network to another the special pattern has been established, so the number of each caller can be easily identified by added digit. On one of the CISCO routers was shown a configuration of MPLS and OSPF protocols. With an analyzer VePAL TX300e, the lab network has been measured to analyze QoS parameters of the network according to standard RFC 2544. Thesis also gives references to lab devices, which have been used accordingly to the work.
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Analysis of Audio Codecs Applied in IP telephony
Hlavica, Michal ; Szőcs, Juraj (referee) ; Škorpil, Vladislav (advisor)
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.
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Automatic Attendant application using Asterisk PBX
Benýšek, Jiří ; Krajsa, Ondřej (referee) ; Kovář, Petr (advisor)
Application of IP telephony is still more and more popular. This technology is designed for large companies as well as for home or office use. If customer needs to use advanced features of the private branch exchanges, he had to purchase more expensive solutions than common equipment. These professional products may be replaced by open source solutions, which can fully replace them. Private branch exchange Asterisk is one example of these products. Bachelor’s thesis is focused on IP telephony, treats of basic principles and network protocols used by this service. This thesis then describes the public branch exchange Asterisk, its possibilities for use in call centers and administration of call queues using this PBX. After theoretical analysis, this thesis deals with installation and configuration of this PBX. It includes installation of necessary operating system, additional packages containing necessary libraries and modules needed for correct function of the PBX. Configuration of Asterisk such as creation of user accounts of SIP protocol and dialplan is described in the next chapter and then all of these functions are tested. Achieved practical results are presented in the last chapter of this bachelor’s thesis.
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Analysis of VoIP implementation in the WAN network of Třinecké železárny a.s.
Pieniažek, Ireneusz ; Skořepa, Michal (referee) ; Molnár, Karol (advisor)
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.
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Communication systems based on IP telephony
Zimek, Josef ; Kapoun, Vladimír (referee) ; Herman, Ivo (advisor)
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.
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Economic and technical aspects of the use of IP telephony in the segment of small and medium-sized businesses
Holásek, Lukáš ; Doležel, Michal (advisor) ; Buchalcevová, Alena (referee)
This work is focused on the introduction of VoIP technology in the environment of small and medium-sized company from techno-economic perspective. The work introduces the VoIP technology in terms of functionality, but also with economic aspects of IP telephony. The aim is to determine whether the transition to VoIP technology may reduce corporate telecommunication costs while contributing to the development of corporate communications. Readers are shown the advantages, but also what the limitations and difficulties are associated with the transition to VoIP technology. The beginning is devoted to basic characterization of classical phone technology, which is good to know when deciding if one should migrate to VoIP. The work also describes the development of the telecommunications market in the Czech Republic in the context of the payment of charges for telecommunications. The practical part analyzes the specific deployment of a VoIP solution to one of Czech companies.
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VoIP- IP network voice communication
BERAN, Václav
The possibility for using the VoIP technology as an alternative solution for the te-lephone system is very attractive. The main reason is the widely expanded computer sites and also their higher effectiveness. The main goal of the work is to describe the VoIP technology and create the first publication in Czech republic which deals with this theme in details. First of all I concentrate on the explanation of the basic words, conceptions and principles necessary to fully understand the whole field. The main scope of the work is VoIP technology which is described in third chapter. There are described also the methods of voice coding, signalling protocols (SIP, H.323, MGCP, IAX) and issues related with QoS. The work also covers the Skype program with descriptions of it's principles, installation and control.
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IP telephony for medium and large companies
Jirák, Tomáš ; Pokorný, Pavel (advisor) ; Jelínek, Jiří (referee)
In this graduation thesis wants introduce possibilities of voice transportation in IP networks like Internet. There are described behaviors of IP network, internet connectivity possibilities, voice protocols included Skype and economical outputs. There are mapped positives and negatives of technology including implementation issues. All economic comparisons are made to Telefonica O2 Czech Republic Inc., which is still telecommunication company with majority in the Czech Republic. There are compared samples of VoIP providers with preferences like company live time, lowest cost and guaranteed quality. Description starts with model situation and continues to real case studies. Case studies describe economic calculation, implementation and target analysis. There are three case studies: small company with fast migration in one time, medium company witch accelerated migration in two steps and large company with conservative and control migration in three steps.
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Možnosti vysokorychlostního připojení k internetu pro vybranou organizaci
Kinská, Marcela ; Toman, Prokop (advisor) ; Kubíček, Jovan (referee)
Tato práce si klade za cíl seznámit čtenáře s problematikou implementace vysokorychlostního připojení k internetu v podmínkách malé až střední organizace (SME). Poté, co čtenáři přiblížím technologie vysokorychlostního připojení vhodné pro nasazení v podmínkách SME, následuje hlavní část mé práce tvoří tématická oblast internetu v organizaci, obsahující možnosti využití vysokorychlostního připojení k internetu, tzv. služby internetu, stejně jako metodiku jeho výběru, kterou považuji za vlastní přínos své práce. Teoretickou část této práce jsem pak rozšířila o případovou studii. Na příkladu z praxe, reprezentovaného středně velkou organizací, uvádím nejen parametry současného i předchozích řešení vysokorychlostního připojení k internetu, ale analyzuji zde i současný stav využití internetu v organizaci. Praktickou část mé práce v závěru doplňuji o konkrétní doporučení, jak využití vysokorychlostní přípojky v podmínkách zkoumané organizace zefektivnit. Vycházím přitom ze znalostí nabitých v průběhu studia odborné literatury.
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Security of Enterprise VoIP Telephony Networks
Šolc, Jiří ; Pavlíček, Luboš (advisor)
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.
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