Soloviov O. Method of VoIP network performance optimizing based on the choice of the voice call route

Soloviov O.V. Method of VoIP network performance optimizing based on the choice of the voice call route. – Manuscript. Thesis for the academic degree of the candidate of technical sciences in speciality 05.12.02 - telecommunication systems and networks. – National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute" of the Ministry of Education and Science of Ukraine, Kyiv, 2020. The booming VoIP market has led to increased competition in the market for these services and the emergence of more VoIP service providers that provide access to the same directions, but with different tariffs and different quality of service. At the same time, modern common and freeware voice traffic routing technologies in VoIP networks are not able to choose the route of voice call, considering the cost and quality of services of different available providers for the requested call direction at real-time. Thus, there is a conflict between the needs of VoIP network operators to maximize the effective use of the available variety of VoIP service providers (to provide their subscribers with quality services at a minimum cost and to increase the level of stability of their own network and to eliminate impact of degradation of service providers) and the actual capabilities of existing voice call routing technologies and methods in VoIP networks. Thus, the problem solved in this work is the lack of sufficient level of automation of routing voice VoIP calls that take into account not only the factors of cost or quality, but also their ratio, and the development of a method of VoIP network performance optimizing based on the choice of the voice call route. The main theoretical and practical results have been formulated and substantiated in this thesis, thаt represent the solution of an important scientific and practical problem of optimization the operation of VoIP systems by improving the technologies of dynamic routing of voice calls and the structural and functional organization of the core IP network, which leads to an improvement in the quality/cost ratio of VoIP communications and increase the level of automation of the VoIP system. Based on the analysis of the existing principles of building VoIP networks, it is proposed to improve the structural and functional organization of the core IP network to meet the requirements of VoIP networks deployed on its basis. A mathematical model for calculating of the metric for choosing of the provider is developed, taking into account the cost and quality parameters, both existing and for the first time proposed synthetic parameters that characterize the quality of communication in a short period. An algorithm for implementing an advanced technology for routing voice calls has been developed based on the generalized provider selection model. An imitation model of the voice calls in the VoIP routing and billing system has been developed, which allowed to analyze the obtained theoretical results and evaluate their impact on the VoIP system without interfering the operation of the communication system of existing operators. The obtained theoretical results are experimentally confirmed by the corresponding measurements of the quality indicators. Based on the research, practical recommendations have been developed to implement obtained results into the practice of development and operating of VoIP solutions, which based on a proposed Method of VoIP network performance optimizing. Key words: VoIP, IP-telephony provider, voice call routing, regression analysis, math modeling.