Fault-tolerance improvement for core and edge of IP network

The fault-tolerance improvement for the core and edge of the IP network is proposed in the given paper. In solving the technological problem of the fault-tolerant IP routing during minimization of the object function it is necessary to solve either quadratic programming problem or mixed integer nonlinear programming problem with limitations defined. The proposed model also provides the support of load balancing functions on the virtual router interfaces and fault-tolerant routing in the core of the IP network with protection schemes of link, node and path, which has a positive impact on the availability and productivity of communications system as a whole.