I am getting a strange repeat error when trying to upload a file to an outside server. This is happening on two different (entirely unrelated) servers. I had the same problem yesterday.

I wonder if the wise people on this forum could help me identify where the problem lies: with my ISP, my own router, or my own computer?

I am using FileZilla. In both cases, the files keep timing out after a set number of bytes. Fortunately, FileZilla is clever enough to restart from where it left off automatically, but it means that the files take a couple of hours to upload whereas they used to take a number of minutes.

The one server consistently times out after 180,224 bytes, and the other after 262,144 bytes. The timeout happens every time after the number of seconds set in Edit > Settings > Connection > nn seconds (so if I set it to 20 seconds, the timeout happens after 20 seconds). But the number of bytes is always the same.

Here is the error message for one of the files (the timeout set to 10 seconds):
Error:    Connection timed out
Error:    File transfer failed after transferring 180,224 bytes in 11 seconds
I have not had this problem before; the last time I tried was one month ago.

Do you have any idea what may be causing this problem?