on last week I have seen a strange traffic behavior on upload throughput, there is a bust of traffic every hour, looking on historic traffic 1 week ago was abou flat:
End of January behavior
Yes, it is correct. Traffic always depends on network usage. Now network is tested so big part of traffic is the test traffic. In the future traffic will depend on clients network usage.
The node itself runs some hourly processes like sending orders etc. But these peaks seem to be bigger than that. Could also be a customer doing hourly backups. Who knows. You can use the debug tools explained in this topic to see what your node is doing during that time.