Progressive rendering and proxy servers

Question

This is my first post!!

Have a large amount of data that is rendered progressively (using classic ASP) and all works fine in IE and Firefox. However, when I view the exact same page from within a school environment (i.e. behind a firewall and via a proxy server) the page only renders progressively in Firefox. In IE (6, 7 and 8) the entire contents of the page are loaded (15 seconds!) before the whole lot is rendered at once.

I'm guessing it's something to do with how IE and the proxy are communicating but I don't know much about this?

Any help at all (other forums (this seems to be the one most likely!) or useful links) would be greatly appreciated.

Mark

Answer 1

Note, Fiddler itself is a proxy, so this can be a confounding factor.

You'll generally want to use a lower-level tool (like NetMon, www.fiddler2.com/redir/?id=netmon) to see what's going on.

It's possible (likely?) the the proxy server is buffering the entire HTTP response (as Fiddler will do unless you push the "Streaming" button) and scanning it for malicious content before returning it to IE all in one block. If it was only doing that for IE user-agents (and not for Firefox) that would explain what you're seeing.

Answer 2

Run Fiddler when and compare the behavior of each browser with and without the proxy.