Abstract- The research and development of the wireless mesh networks (WMNs) now still popular. P2P was an old virtual overlay network on top of physical network. Open chord as varian of chord is a tool based on distributed has table that can be used to build overlay. In swarm intelligence presented the particle swarm optimization (PSO) algorithm. One application of the algorithm named sensor PSO for square area sensor networks. We had modified this application for free rectangle area networks. In this paper we report a study how to build an overlay network based on Open Chord. The objective of our study is to use overlay network to efficiently find the resources currently available in the WMNs. Our application firstly read the output of Sensor PSO for building an underlay network, then built a virtual overlay on top of the underlay. The virtual overlay network resulted can be used for routing simulation.