I. Introduction
Amount of data traffic between every pair of network ingress/egress points is called traffic matrix. Ingress/egress points may be edge routers, PoPs, or ingress/egress links of the network. Understanding traffic matrices is crucial for network operation. For example, it can be used to understand current network status, and to design network (e.g., capacity design, topology design) in mid to long-term [1] [2].