In the last decade, the Internet of Things (IoT) technologies have brought a lot of applications in different fields. Many communication technologies have been developed in order to connect everything to each other and to the Internet. Besides, the long-range power-efficient wireless technologies have emerged such as LoRa (Long Range), which enables transmission over long distances with low energy consumption and can work within p2p, star or mesh topologies. In this paper, we analyze a model of a mesh topology for the LoRa network, which is attracting more interest in the applications of Smart City and Smart Agriculture. While the mesh topology is described by a graph, a method of route selection is considered based on the link quality related to Received Signal Strength Indication (RSSI) to find the optimal path from a source to a sink node. The network performance is evaluated by considering each node as a queueing system. As the analytic results, the routes are found from device nodes to the gateway, and the delivery latency is analyzed in the dependence on the load intensity and the number of relay nodes.