Progressive rendering and proxy servers

Question

Hi

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

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

Answer 2

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 3

Thank you very much for this information. I installed Fiddler, and yes you are right, as it is a proxy it causes the page to load all in one block after 15 seconds. Interestingly, when in Firefox, I now also get the long pause before the page loads in a single block (this is different to how it responds when going through the proxy in a school).

I will go through the logs Fiddler generates and also try NetMon. Is there likely to be a solution that could be implimented by users? If I click the 'Streaming' button in Fiddler it does help but how does this work in a more general setup with standard proxies etc? Could the solution be to change some option on the proxy server, the browser itself or the by adding something to the asp code?

Thanks, Mark