It is important to evaluate the performance of large com-munication networks prior to their deployment, in partic-ular if economic interests are involved. In wireless multi-hop mesh networks, a communication message is transferred from a source to a destination via multiple nodes. Typi-cally the message can be transferred via multiple routes in a mesh network, because several nodes are in communica-tion range. During the design phase of such a communica-tion network, specific characteristics need to be considered in order to avoid boundaries like bottlenecks and dead-end problems of the deployed system. Hence these kinds of prob-lems must be avoided prior to the network deployment. In this paper, we present a system design framework for the OMNeT++ simulation environment, which is able to iden-tify potential bottlenecks and maximum loads of multi-hop networks. The process is presented via a realistic use case scenario for an Energy Management Application, in which geographic routing algorithms are used to identify the short-est route to a destination. The results of the performance evaluation enabled us to support the communication design process with information about reliability, data rate and routing schemes.