Just watched an ATLAS result that postponed it's upload after 110 of 122 MB and nearly 15 minutes.
My router's traffic monitor switched between 100% (a few seconds) and 0% speed (several minutes).

The internet connection was unused except for the upload of a 60 MB LHCb result at full speed.


The rest of the ATLAS upload was then finished within a few seconds and a few minutes later the same host downloaded a fresh ATLAS task (300 MB) at normal speed.