Zusammenfassung
Network monitoring is a complex task and is always a trade-off between
granularity of information and the performance impact of the monitoring
itself on the network. SDN controllers, such as the ONOS SDN controller
make this challenge easier as they can supply centralized information over
the whole network. In our previous work we mathematically analyzed the
built-in detection mechanism of ONOS and revealed a lack of detection
performance and the vulnerability of this process to jitter. These results
were also verified by measurements. In this paper we present an Active
Probing extension for the ONOS SDN controller that overcomes these
shortcomings by emitting probing packets that are transmitted through the
network. Statistics over a history of those packets allow for the detection
of packet loss. The evaluation by the means of measurements proves the
benefits in terms of detection performance and controller load of this
application. Furthermore, our extension is able to detect jitter being
present in the network and to automatically adapt the probing process to
these conditions.
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