Volumetric (Distributed) Denial of Service attacks remain one of the major threats for any organization, capable of saturating most Internet access links through the usage of botnets and amplification techniques. The only effective mitigation mechanism today is the redirection of the network traffic towards scrubbing centers; this protects the Internet pipe of the victim, but does not prevent wasting resources in other parts of the network.In this paper, we leverage the cloud-native design of the 5G architecture to monitor traffic statistics at the edge of the network, which are then processed by a powerful Analytics ToolKit (ATk). Our work is based on the framework designed by the ASTRID project, which allows to automatically change the inspection probes while chasing a better balance between the granularity of the collected data and the overhead. We demonstrate our approach for an NTP amplification attack; the ATk is first trained with historical data and then used to detect deviations from the expected traffic profile, by switching between normal/warning/alert states. Our preliminary results show that it can correctly distinguish between periodical fluctuations of requests and attacks and tolerate a few data losses.