The article describes the main disadvantages of modern mathematical models of TCS. А recursive flow model for MPLS networks, based on a sampling of incoming traffic is adjusted. Restrictions that allow to take into account packet loss when sending traffic over the network are modified and added. As the objective function is proposed to use the valuable information transfer rate, which allows to take into account not only prioritize traffic by class of service, but also on traffic source and destination points.
flow model, quality of service, valuable information transfer rate, packet losses