RINGLM: A Link-Level Packet Loss Monitoring Solution for Software-Defined Networks

Monitoring packet losses at links is beneficial to network management and service quality improvement. Software-defined networking can conveniently obtain flow statistics. However, the packet loss rate of a link or path cannot be directly measured by acquiring the statistics of an ongoing flow. In addition, monitoring the packet loss directly based on statistics inquiries brings considerable extra overhead to the controller. In this paper, we propose a two-way link-level packet loss monitoring solution for the software-defined networks. We propose a packet loss probe structure consisting of distributed rings. The proposed probe structure contains every monitored directed link once and only once, thereby avoiding the mutual interference between different probe flows and thereby improves probe accuracy. We further study two optimization problems of the ring-based packet loss probe structure. The two problems build probe structures, with minimal maximum ring delay, for all the network links and selected network links. The two optimization problems are very complex, and we approximately solve them in polynomial time. A packet loss positioning algorithm, based on flow statistic inquiries and the symmetry design of probe rings, is also proposed. Our proposed solution can effectively monitor link-level packet loss but brings low and controllable overhead to the controller.