Scientific results of the DCCN-2021 conference held in V.A. Trapeznikov Institute of Control Sciences of Russian Academy of Sciences and RUDN University on September 20-24, 2021 are presented. One of the important lines of research of ICS RAS is the development of theoretical foundations for design of advanced telecommunication networks and practical implementa-tion of large-scale projects of broadband wireless networks design. In this regard, for many years ICS RAS has organized the international conference on “Distributed Computer and Communications Networks: Control, Computation, Communications”. DCCN-2021 brought together researchers and developers from academia and industry across various countries, working in the area of theory and applications of distributed computer and telecommunication networks, mathematical modeling, methods of control and optimization of distributed systems, by offering them a unique opportunity to share their views as well as discuss the perspective developments and pursue collaboration in this area. The popularity of the conference is con-stantly increasing. Despite pandemic restrictions, in 2021, more than 240 participants from 26 countries presented 151 papers. The global reach of the conference, in particular, is emphasized by the list of plenary speakers, which includes leading experts in the field of theory and practice of telecommunication networks from USA, Israel, Hungary, Portugal, Italy, India and Russia.