SUMMARY
The subject matter of the article is information and communication networks (ICN) of critical infrastructure systems (CIS). The goal of the work is to create methods for managing the data flows and resources of the ICN of CIS to improve the efficiency of information processing. The following tasks were solved in the article: the data flow model of multi-level ICN structure was developed, the method of adaptive distribution of data flows was developed, the method of network resource assignment to multi-server nodes was developed. The following methods used are –methods of mathematical statistics for random processes, the theory of queuing systems, methods of optimization theory and operations research. The following results were obtained – the principles of managing the distribution of network traffic in the ICN of CIS were formulated and the practical requirements arising in the efficiency of data transmission were determined. The possible approaches to the formulation and solution of the listed problems were suggested according to the developed general approach to network management. The multi-level information structure was investigated. The mathematical model of data flows of a multilevel information structure of the network was developed; it has a three-level unstratified structure and consists of a number of subnets and groups of nodes. The method for adaptive management of data flows distribution was developed; this method includes the stratified two-level management which is based on the development of a multidimensional space of the network state and management parameters taking into account user activities. The management is carried out at the first level by setting the basic parameters of the network, at the second – by operational management with constant basic parameters. The method for distributing the resources of a multi-server information processing node was developed, as server systems are considered as a set of single-line queuing systems and information about the distribution of the bandwidth of communication channels is used. Conclusions: using the method of the adaptive management of traffic distribution enables reducing the time for processing system transactions and total costs for maintenance. The use of the method resource distribution of the server node in the course of re-engineering CIS processes minimizes the costs of servicing the data flows.