In this paper we introduce a two-phase dynamic loadbalancing technique for P2P computing systems. The first phase consists of mapping a P2P network onto a hierarchical topology based on 1-D space tessellations. This hierarchy is called TreeP (Tree based P2P architecture). The second phase consists of balancing the load among the peers using the PSLB (Positional Scan Load-Balancing) technique, which is well suited for regular topologies. We study this technique and optimize its implementation on the TreeP topology. This technique is simple, efficient, scalable, and does not introduce a considerable overhead as shown in the experimental results and theoretical study.