Increasing HTTP file transfer times

This was a very hard problem to diagnose and find out about. I have to admit that the other problems may be unexpected, but they aren't very hard to solve – however this one was. It was only down to my persistence at finding a solution that led me to cracking it in the end.

Context

I was implementing a HTTP server for an application written in Qt that would add a Representational State Transfer (REST) interface to a redesigned product for my customer. The new release should have transformed their, as yet desktop-only and Windows-only application into a cross-platform, distributed, client-server application using an HTTP API for communication.

The specifics of my customer&apos...