An anomalous change in traffic distributions caused by an external inter-domain routing change leads to congestion of some network links, which then affects the network quality or disrupts traffic. Thus, network operators need to promptly deal with these problems by changing the routing policy or by soliciting the help of an involved or neighboring network operator through operator channels. In addition, they need to diagnose situations in which customers are affected by the incident or in which destinations become unreachable. Although this task is indispensable, understanding the situation is difficult since the cause lies outside the operators' network domains. To alleviate the load on operators, we developed a system for monitoring traffic shifts and the disruptions caused by BGP routing changes. It is challenging to extract information that is more valid from a large amount of BGP update messages and traffic flow records. By correlating these data, the system provides meaningful reports and visualized traffic statistics, and it enables operators to easily detect the cause of traffic changes and to investigate the extent of damage. We demonstrate the effectiveness of the system and evaluate its feasibility by applying it to an ISP backbone network. In addition, we present a case study of traffic changes that the system detected.

This paper presents a method of measuring the traffic of IP multicast streaming, such as IPTV, by using IPFIX and PSAMP. The IP multicast streaming service has recently become one of the popular network services, but no IP multicast operation method has been established yet. In particular, traffic measurement of IP multicast streaming encounters two challenges: as monitoring a multicast path tree and QoS measurement. There is no method to monitor them continuously in large-scale networks. Hence, we explore measurement structure suitable for large-scale networks, and then using IPFIX and PSAMP, we propose an efficient a network-level quality measurement method for IPTV and a method to extract multicast path tree data. In addition, we demonstrate the feasibility of the measurement method by evaluating a prototype system.