Recursive Diagonal Torus (RDT) is a class of interconnection network consisting of recursively overlaid twodimensional square diagonal tori for massively parallel computers with up to 216 nodes. Connection structures of the RDT vary according to the assignment of upper rank diagonal tori into a node. Although traditional simple assignment called RDT(2,4,1)/ shows enough performance under the uniform traffic, the congestion of low rank tori degrades the performance when local communication is dominant. In this paper, RDT(2,4,1)/ torus assignment is proposed, focusing on improving the performance for local communication. With a simplified simulation algorithm, result shows that RDT(2,4,1)/ improves the average distance compared with RDT(2,4,1)/ assignment when considering local area.