To efficiently monitor the link performance in an OpenFlow network with a single measurement box (referred to a “beacon”), this paper presents a measurement scheme that calculates a set of measurement paths from the beacon to cover all links in the network based on the controllable feature of individual measurement paths in the OpenFlow network and comprehensively estimates the performance of all the physical links from round-trip active measurements. The scheme has a novel feature that minimize the maximum number of exclusive flow-entries for active measurements on OpenFlow switches by utilizing common packet header values in the probing packets to aggregate multiple entries into a single entry to save the resources in OpenFlow switches and controller. We demonstrate the effectiveness and feasibility of our solution through simulations and emulation scenarios.

This paper presents an IP performance management system having the triple frameworks of performance measurement, topology monitoring and data analysis. The system infers the causal location of the performance degradation with a network tomographic approach. Since the Internet is still highly prone to performance deterioration due to congestion, router failure, and so forth, not only detecting performance deterioration, but also monitoring topology and locating the performance-degraded segments in real-time is vital to ensure that Internet Service Providers can mitigate or prevent such performance deterioration. The system is implemented and evaluated through a real-world experiment and its considerable potential for practical network operations is demonstrated.

Since congestion is very likely to happen in the Internet, locating congested areas (path segments) along a congested path is vital to appropriate actions by Internet Service Providers to mitigate or prevent network performance degradation. We propose a practical method to locate congested segments by actively measuring one-way end-to-end packet losses on appropriate paths from multiple origins to multiple destinations, using a network tomographic approach. Then we conduct a long-term experiment measuring packet losses on multiple paths over the Japanese commercial Internet. The experimental results indicate that the proposed method is able to precisely locate congested segments. Some findings on congestion over the Japan Internet are also given based on the experiment.