The paper proposes an improved mathematical model of load balancing in the infocommunication network (ICN), corresponding to the Traffic Engineering (TE) concept principles. The model mathematically formalizes the case of ICN construction when each access network is switched simultaneously to not one but to several border routers to increase fault tolerance. Therefore, it is proposed to improve the load balancing level in the ICN according to the TE criterion by ensuring the distribution of traffic at the access level between several border routers that create a default virtual gateway. The proposed mathematical model is based on the conditions of implementation of single or multipath routing; load balancing at the access level; flow conservation at the access level and the network itself; overload prevention of communication links, which act as conditions for load balancing in ICN. Within the proposed model, the load balancing task in ICN is formulated as an optimization problem of mixed-integer linear programming. The results of the study confirmed the effectiveness of the proposed solution. Ensuring coordinated load balancing at both access and core network levels, in general, has increased network performance by 25.45% compared to a solution based on multipath routing, but without access level balancing, and 2.76 times compared to the model in which load balancing in the ICN was absent. Within the available load for each of the compared models, the use of the proposed solution allowed to reduce the upper bound of the network links utilization by an average from 20% to 60%. Lowering the upper bound of the network links utilization positively affects the quantitative values of the main Quality of Service indicators – the average end-to-end delay, jitter, and packet loss probability.
Traffic engineering in a computer network based on the multipath routing protocol