Description: The analysis of approaches of mathematical design of the informatively-telecommunication systems is conducted on the whole, and possibilities of mathematical design of modern telecommunication networks by the GERT-net in particular. The mathematical model of multiservice communication channel is developed on the basis of exponential GERT-net. Analytical expression is got for the calculation of closeness of distributing of time of transmission of report in the channel of connection of network of NGN. A theorem is proved about impossibility of generation of poles of the second and third order, certain as a result of mathematical design, by a polynomial.
Keywords: multiservice communication channel, mathematical model, count, networks of NGN, GERT-net