Wolf, what I can add from server side is that telematic unit configuration is extremely different. Amount of messages can be 1 mln or it also can be 10 millions in other configurations. Adding here various message parameters info the difference in size of data can be up to 100 times for the same period.
All of these can really impact on the processing speed. And on unit level it is not visible (e.g. no matter it is 0.1s or 5s), but in group reports this can be the reason of 2 mintes timeout for report execution.
So we are not the gods, we have limits and to enlarge them it is also important to configure devices that only important information is being sent to server.
At the dark side