Muhi-Aldeen H. Models and methods of providing quality of services in network with virtualization support

The actual scientific and applied problem is solved in the work, which consists in development of new and improvement of existing methods of analysis of distribution of network resources; assessment of the correctness of the functioning and provision of services in multiservice networks with NFV technology support. To solve the scientific-applied problem, the following methods were developed: the method of dynamic management of the composition of complex services by changing their components in NFV networks, which allows to form and manage the composition of the complex service, taking into account the current state of the complex services in the formation of the complex service, which leads to the required level of QoS; dynamic bandwidth allocation method for NFV networks based on the principles of residual bandwidth allocation and avoiding full load and overload of the transmission channel; dynamic replication method that increases the availability of services as the service grows in popularity on the NFV network. It is determined that the proposed method of load balancing can increase the efficiency of use of transmission channels by 7% and reduce the average delay by 16% in comparison with the dynamic algorithm of Central Queuing, and the application of the developed method of replication of services allows to increase the service availability by 14 times in case of overloads. In order to analyze the efficiency of the distribution of network resources, it is proposed to analyze the functional and non-functional properties of the service using a model approach. It is proposed to use the E-network apparatus as a mathematical simulation apparatus. It is suggested to analyze such algorithmic properties as: boundedness, activity, reachability and security.6. A dynamic replication method has been developed to increase the availability of services as the service becomes more popular on the NFV network. To model the change in network characteristics in the service delivery process, the application of network computing theory is proposed, on the basis of which a number of definitions have been made, which allow the most complete modeling of NFVI elements. NFVI behavior analysis methods are proposed in two time models: continuous time: load and service curves and discrete time: arrival and departure function. Algorithm for reservation of resources in the provision of services based on the use of elements of the theory of network computing. The method is based on algorithms for analysis and estimation of the limit indicators of delay and speed of processing, which are characteristic for each node. A practical example of reserving resources using RSVP. The method of dynamic replication of services in networks with support of functions of virtualization of network resources is developed, which through the use of network computing theory allows to increase the availability and efficiency of rendering services by timely formation, deleting of copies of different types of services and their rational distribution between fragments of the network. The proposed mathematical models and methods can be used in the development, implementation and maintenance of cloud-based multi-service networks using network function virtualization technology.