Fabio: On Wed, Sep 9, 2020 at 1:05 PM Fabio Ugo Venchiarutti <f.venchiarutti@xxxxxxxxx> wrote: > Even if network datagrams moved at the speed of light and with no > serialisation/forwarding delay (which they don't), you're still going to > deal with several thousand KMs of distance; I'm positively surprised > you're getting such short round-trip times as it stands. Light travels at about a foot per nanosecond in air/vacuum, 20 cm per nanosecond in glass IIRC, so you can RTT 10cm per nanosecond in fiber. This amounts to 100km per millisecond. 1200 to 1600 km in 12-16 ms. East-1/2 are N.Virginia / Ohio, which can be from 240 to 950 km apart ( on a quick google maps measure, not several thousands ), depending on the exact place. And Amazon has really fast pipes going between their regions, so this is not surprising. I have 55ms from ireland (eu west 1) to N.Virg., and they are 5500 km over the great circle. Francisco Olarte.