Thanks Roman. > So did you apply both of that, and what was the effect?
I will create a new environment this afternoon and test the MTU changes mentioned earlier and investigate the outcome. > What are the other point that you test against, is it another VPS (better if > you could try with that), or your home connection? The iPhone is connected via Wifi to the home network, which is 500 Mbps / fibre. I have a code snippet on the iPhone that downloads a 1 GB test file from my AWS bucket (London) for 10 seconds. Then measures totalBytesWritten / time elapsed / (1024.0 * 1024.0) * 8.0. Which is the formula for Mbps as far as I am aware. Client (iPhone) --> server (VPS) --> S3 (AWS) = 117 Mbps Client (iPhone) --> S3 (AWS) = 506 Mbps I run this once the Wireguard connection is established and I get 117 Mbps. Then I disconnect the VPN and run the same code again to fetch the test file without VPN that comes down to 506 Mbps. Client (iPhone), server (VPS) and S3 (AWS) are all in located London, UK. I have run your iperf test. On the VPS the Lost/Total Datagrams is 0%. On the client (Mac) the Lost/Total Datagrams is 0.13%. This test proves that the ISP isn't messing around with UDP. [ 5] local 192.168.1.101 port 62103 connected to xxxxx port 5201 [ ID] Interval Transfer Bitrate Jitter Lost/Total Datagrams [ 5] 0.00-1.00 sec 59.5 MBytes 499 Mbits/sec 0.034 ms 0/44538 (0%) [ 5] 1.00-2.00 sec 59.7 MBytes 500 Mbits/sec 0.012 ms 0/44677 (0%) [ 5] 2.00-3.00 sec 59.3 MBytes 497 Mbits/sec 0.021 ms 15/44400 (0.034%) [ 5] 3.00-4.00 sec 60.0 MBytes 503 Mbits/sec 0.015 ms 0/44913 (0%) [ 5] 4.00-5.00 sec 59.5 MBytes 499 Mbits/sec 0.020 ms 0/44588 (0%) [ 5] 5.00-6.00 sec 59.3 MBytes 498 Mbits/sec 0.018 ms 219/44662 (0.49%) [ 5] 6.00-7.00 sec 59.6 MBytes 500 Mbits/sec 0.065 ms 0/44633 (0%) [ 5] 7.00-8.00 sec 59.6 MBytes 500 Mbits/sec 0.037 ms 0/44614 (0%) [ 5] 8.00-9.00 sec 59.6 MBytes 500 Mbits/sec 0.024 ms 0/44633 (0%) [ 5] 9.00-10.00 sec 59.2 MBytes 497 Mbits/sec 0.024 ms 339/44686 (0.76%) - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Jitter Lost/Total Datagrams [ 5] 0.00-10.01 sec 596 MBytes 500 Mbits/sec 0.000 ms 0/446756 (0%) sender [SUM] 0.0-10.0 sec 657 datagrams received out-of-order [ 5] 0.00-10.00 sec 595 MBytes 499 Mbits/sec 0.024 ms 573/446344 (0.13%) receiver For now I'm out of ideas. I will try to play around with MTUs this afternoon and see what happens. Thanks, > It could be your home provider has different speed limits (shaping) in place > for UDP. Should be possible to test this with: > > iperf3 -s # on VPS > > iperf3 -u -b 500M -c <VPS IP> -R # on the other side > > And then see how many "Lost/Total Datagrams" (xx %) you get. A high percentage > would indicate that the actual top speed for UDP is less than 500Mbit by this > value. > > -- > With respect, > Roman