first 15 seconds of FASP transfer

If we zoom in and look at the first 15 seconds of the transfer we can see more details. One of these is that we can see that after a few packets are sent from the client to the server, that the server starts to linearly increase the rate at which it is sending packets. However, after some time it stops increasing its rate and the sending rate goes up and down by small amounts. A second detail is that we can see that there were some intervals where the client did not send packets to the server and it is during these intervals that the server reduced its sending rate.

First ~15 seconds of the transfer
Plot of the first ~15 seconds of the FASP transfer

33001 is the source UDP port of server
42132 is the source UDP port of the client

Transcript

So let's zoom in on that a little bit.  What do we notice here? We noticed that the rate that the server sends is initially slow; it linearly ramps up until it is sending out this higher rate, but every once in a while, there are examples such as this, and here and here where the rate it is sending at is much lower.  And we know that, of course, it is having to compete for some traffic with other nodes who are sending traffic along the same path.