You're not necessarily wrong, but uIP may not be the best example of a good minimal TCP implementation. I've seen it routinely put the wrong value into the TCP

You're not necessarily wrong, but uIP may not be the best example of a good minimal TCP implementation. I've seen it routinely put the wrong value into the TCP window-size field. This creates an illusion of packet loss, causing senders to retransmit and performance to drop exponentially to zero. As a workaround, I wrote a custom tool that avoids sending more than one TCP segment at a time: https://github.com/dlitz/dlink-firmware-uploader/blob/581b64654cdbc8bda1e674c42d1cc9a4ba4a7953/upload.py#L47 https://github.com/dlitz/dlink-firmware-uploader/blob/581b64...