Romanchuk V. Resource management methods and algorithms for multiservice information function-oriented corporate networks.

The dissertation is devoted to solving the actual scientific problem of ensuring the quality of provisioning of info-communication services by improving the efficiency of information exchange in multiservice information functional-oriented corporate networks on the basis of the creation of a method for adaptive control of structural parameters of network devices and the development of mathematical models and algorithms of servicing queues. The problem of adaptive structural and functional synthesis of the logical infrastructure of the corporate network has been formulated. The modified method for managing queues in multiservice nodes of the network is contributed. This method allows to increase the efficiency of network resource distribution based on the end to end quality of service through dynamic adaptation of buffer and channel resources. The structural and functional model of network device with resource virtualization has been proposed. This model allows to deploy several software analogs of hardware routers on the same physical machine for servicing different types of traffic. The entropy method of detection of network traffic anomalies has been proposed for increasing the stability of the corporate network system against cyber-attacks. The mathematical model of the functioning of the virtualized router has been presented. The model allows to determine the performance of the network and assess the scalability of the corporate infrastructure in accordance with the agreement on the level of service provisioning. A new generation virtual network test platform with software-driven routers has been deployed to enable the adaptive selection of queuing algorithms in the context of the emerging phenomenon of random traffic bursts, which are typical for multiservice networks of the new generation. The adequacy of the developed models has been confirmed through the investigation of probabilistic properties of traffic in multiservice corporate networks and comparison of the processing delay with the real hardware router. As a result of simulation and practical experiments, it has been proved that application of developed models and methods of corporate network resource management leads to improvement of the quality of service of real-time streams (on average, service delays have been reduced to 2 times and the probability of loss of packages by 3%). The study of the quality of service for streaming traffic has been conducted on the basis of the developed model of the software router through deploying virtual devices per traffic class. By conducting an experiment in a multiservice network, it has been proved that application of the developed models and the method of dynamic virtualization of the network device provide the possibility of assigning the minimum required volume of network resources to guarantee a given level of quality of service and gives the opportunity to increase the quality of streaming video traffic by 25-30% according to the criteria of delay and jitter. The gain on the quality of experience of the real time video content after the application of the proposed solutions for managing network resources by performing a full-scale experiment has been confirmed through experiments.