The server-side code in `store_bandwidth` seems a bit copy-pastish. The `in_time` and friends is computed 3 times, once thrown away without any use, twice in a very similar way. It would be better to have just one run of computing it and optionally sum the existing data in DB to it by some kind of `map` trick, or calling the same summing function on all 4 arrays. Also, consider better way to handle invalid data (for example bucket with max. speed 0) from client. Ignore the one bucket? Or ignore the whole client? Anyway, the current try-except around the whole client is just a hotfix and should be improved. See #33.