I. Introduction
A multi-criteria problem associated with the design of engineering communications can be formulated in gen-eral as follows: from a variety of options it is necessary to choose a design solution under given constraints that provides a minimum of total costs. One of important constraints is that that the projected network topology must satisfy a given reliability threshold. Another for-mulation consists in replacing the optimized criterion with reliability (with a transition from minimizing to maximizing the objective function) and replacing the threshold indicator with cost. Such problems are NP-hard, which was investigated [1]. In this paper, the reli-ability indicators of engineering network are analyzed.