I realise this might be an impossible question to answer, but here goes:
I have an embedded board that I've written a load of software for; this board can be sent a new firmware image (image here is not a picture, but an update of the software that will run on the board) via a web browser. The web browser is run on an ordinary computer and is served by the embedded board. So, you open a browser on a computer, type in the IP address of the embedded board, and the embedded board serves up a page to allow you to choose a new firmware image for this embedded board.
Now, I've been developing this on Linux; I mean the software for the embedded board and therefore the browser I have used has been on my Linux machines. When I try to repeat this on Windows it is dog slow!
Looking at it with Wireshark, the Windows machine sends out a packet containing new firmware data, the embedded board sends out an ACK 400μs (four hundred microseconds) later. The Windows machine immediately sends out the next packet and the ACK, again, is returned again after a few hundred microseconds.
However, the next packet after this four-packet burst is sent five seconds later, and the rapid four packet sequence is repeated.
This continues, with four-packet bursts then five-second gaps. When you have a file of 586K, this makes it painfully slow.
If you send the file using a Linux machine, it takes a few seconds to send the whole image.
I have tried his on two Windows machines and two Linux machines with identical results. I haven't used Windows "properly" in years and I don't know my way around it at all. I'm wondering whether it might be a firewall issue (but then why would it let stuff through, albeit slowly?).
Can anyone throw any light on this or make any suggestions on why it would be please? I'd love to be able to tell my customer just to use Linux, but I don't think that would go down well! ;~)
Edit:
I've added pcap files in case they help. Please note, I stopped the Windows one part way through as it's so slow. The Linux one completes the file transfer. Windows Slow upload pcap