Monitoring System of Service Availability for IP Telephony Providers

Import 05/08/2014Diplomová práce řeší návrh a realizaci způsobu monitorování služeb a klientských zařízení využívajících SIP protokol. Pro realizaci jsem vybral vhodný dohledový systém a zvolil způsob ověření dostupnosti SIP klientů včetně funkčnosti propojení mezi poskytovateli SIP služeb. Součástí je rovněž monitorování kvality hovoru a praktická realizace monitorovacího systému s notifikací událostí e-mailem a SMS zprávou.The graduation thesis deals with the proposal and realization of the method of monitoring of services and client appliances using SIP protocol. For the realization I have chosen a suitable supervisory system and selected the way of checking accessability of SIP clients including the functionality of connection between SIP service providers. The part is also devoted to monitoring of the quality of conversation and practical realization of the monitoring system with the incident’s notification by e-mail and SMS.460 - Katedra informatikyvýborn

Robustness of VoIP Systems

Katedra telekomunikační technik

Voice over IP. Competition Policy and Regulation

Traditionally, there have been two separate telecommunications networks, one based on switches, the other based on routers. The switched network basically carried voice. The packet switched network basically carried data. Now voice is about to go packet switched too. Ultimately, both networks might merge. If that were to happen, the governance structure of either of these networks would have to change fundamentally. Currently, a large amount of packet switched traffic goes over the public Internet. The Internet is organised as a club good. There is an access fee, but no further fee for its actual use. Volume metering is technically feasible, but typically only bandwidth is controlled. In the switched network, a split price is standard. There is an access fee, plus a separate fee for each call. In a club good, by definition each side pays for part of the traffic. On the Internet, the receiver pays principle is thus applied. In most countries, the switched network is governed by the caller pays principle. Under that principle, there are termination charges. Each operator has a local monopoly over its customers. There is thus the possibility that telephony will in the future be controlled by the same principles. Actually, in that case the only remaining property right would be access to the network. In the opposite case, data traffic might be contaminated by the principles currently governing switched telephony. This would presuppose that operators succeed in introducing artificial property rights for the relationship with their customers, maybe even for the individual instance of communication. Technically, there are two main opportunities for this. In switched telephony, for technical reasons it is natural to give out telephone numbers to operators, not to clients. Through these numbers, they control their customers. Voice over IP operators try to implement the same scheme for packet switched voice traffic, although here the domain name system would be natural. Domains are accorded to end users, not to operators. A second conduit for artificially introducing property rights is technical standards. They are needed for defining addressees, for the management of real-time interaction, and for the digital coding of voice signals. By way of proprietary standards, the operator gains full control. Competition policy should not only see at the establishment of these fundamental governance structures. It should also check the potential for distorting systems competition between switched and packet switched telephony. Incumbents are having a host of potential strategies for creating new barriers to entry, and for distorting actual competition. Most critical are bundling strategies. Diagonally integrated incumbents might offer their clients to carry their traffic over IP where possible, and through their traditional network otherwise. That way they could turn their customer base in the traditional networks into a barrier to entry. Currently, this strategy can fully work for mobile telephony. In fixed telephony it is more difficult to implement as long as IP addressees are not earmarked.property right, club good, network externality, monopolistic competition, systems competition, packet switched telephony, network access, E. 164 numbers vs. IP addresses, caller pays principle vs. receiver pays principle, sip, codecs

SIP/H.323 gateway with Asterisk PBX

Tato bakalářská práce se zabývá problematikou internetové telefonie a jejího užití v dnešním světě, který nabízí mnoho způsobů, jak komunikovat mezi lidmi. Internetová telefonie dává telefonování další rozměr a ukazuje nové možnosti využití protokolu IP. Práce se zaměřuje na nejvíce používaný protokol zprostředkovávající funkce technologie VoIP a to standard H.323 a ještě protokol SIP, který i když poskytuje stejné funkce jako H.323, je založen na jiném principu a díky své jednoduché struktuře připravuje dobré podmínky pro vznik nových aplikací a služeb v internetové telefonii. Pojednává se zde i o Open Source pobočkové ústředně Asterisk. Asterisk, nejen díky využití Voice over IP, poskytuje oproti standardním analogovým pobočkovým ústřednám řadu výhod a díky své modularitě a rozšiřitelnosti nabízí také mnohem více možností konfigurace. Základním protokolem, se kterým Asterisk pracuje, je Session Initiation Protocol (SIP). Standard H.323 není v základní instalaci Asterisku implementován, proto je nutné ústřednu vhodně doinstalovat a nakonfigurovat ji, aby se funkce ústředny rozšířila o práci s tímto standardem a dokázala provádět i překlad mezi protokolem SIP a standardem H.323. Výsledky, kterých jsem dosáhl, jsou uvedeny v kapitole „Dosažené výsledky“ a v závěru bakalářské práce.This Bachelor’s thesis is engaged in problems of the internet telephony and its usage in today´s world, which offers many techniques how communicate among people. The internet telephony gives telephoning other format and shows new possibilities of IP protocol´s usage. The thesis is focused on the most used protocol corveying functions of VoIP technology, it is the standard H.323 and also the SIP protokol, which even if provides the same functions as H.323 is based on the different principle and because of its easy structure, it prepares good conditions for rise of new applications and services in internet telephony. In this thesis the Open Source private branch exchange Asterisk is also discussed. Asterisk, not only thanks to the usage of Voice over IP provides against the standard analogue private branch exchange many advantages and thanks to its modularity and expansibility also offers much more possibilities of configuration. The Session Initiation Protocol (SIP) is the basic protocol, with which Asterisk works. The standard H.323 is not implemented in the basic installation of Asterisk, therefore it is necessary to do its suitable installation and congiruation, in order to expand exchange´s functions for work with this standard and also to be able to realize translation between the protocol SIP and the standard H.323. The results, which I accomplished, are presented in the chapters „Dosažené výsledky“ and in the conclusion of the bachelor’s thesis.

Competition in a Pure World of Internet Telephony

From the angle of competition policy, Voice over IP looks like a panacea. It not only brings better service, but it also increases competitive pressure on former telecommunications monopolists. This paper points to the largely overlooked downside. In a pure world of Internet telephony, there would be no charge for individual calls, nor for telephony, as distinct from other services running over the uniform network. Specifically, establishing property rights for either of these would be costly, whereas these property rights were automatic and free of charge in switched telephony. Giving voice over IP providers classic telephone numbers would enhance systems competition with switched telephony. But this would make it more difficult for clients to swap providers. The anti-competitive caller pays principle would extend to IP telephony.property right, non-linear pricing, pure bundling, club good, cross-subsidisation, packet switched telephony

Analysis of VoIP implementation in the WAN network of Třinecké železárny a.s.

Tato diplomová práce je zaměřena na implementaci technologie VoIP ve vzdálených pobočkách velké firmy. Je zde využito stávajících WAN linek, které byly dosud určeny pouze pro přenos dat. Nasazení IP telefonie rozšiřuje využití těchto linek a zároveň snižuje náklady na provoz telefonních služeb. Jsou zde popsány modely pro návrh, a také samotný návrh řešení IP telefonie pro konkrétní firmu.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.

Telecommunication System Analysis and Design in Manufacturing Company

Import 26/06/2013Bakalářská práce se zabývá analýzou, výběrem a návrhem implementace optimální varianty v oblasti telefonie firmy. Hlavním cílem práce je vyřešit požadavek společnosti na zvýšení nedostatečné kapacity současné telefonní ústředny. Přáním firmy je, aby nové řešení přineslo zvýšení počtu připojitelných linek, snížilo pravidelné náklady a otevřelo cestu k budoucímu rozvoji. V práci bylo navrženo pět variant řešení, dvě vycházejí z možností současné digitální telefonie a tři využívají technologii VoIP. Pomocí rozhodovací analýzy byla vybrána varianta pořízení vlastního serveru s instalací Asterisk. Byly popsány výhody tohoto řešení a navržen postup implementace. Práce by měla posloužit jako podklad pro efektivní rozhodnutí firmy.This thesis deals with the analysis, selection and implementation of optimal variants in the area of company telephony. The main goal of this work is to solve a company’s requirement to increase the currently insufficient capacity of its telephone exchange. The company’s objective is to have a new solution with more connected lines and decreased regular costs, which will lead to future development. There are five variants in this work. Two of them come from possibilities which current digital telephony offers and the three other variants use VoIP technology. Through the use of decision analysis the variant of the company buying its own server with Asterisk installation was chosen. The benefits of this solution were described and an implementation procedure was proposed. This work should serve as a basis on which the company can make an effective decision.155 - Katedra aplikované informatikyvýborn