While trying to debug a bandwidth problem on a 3G connection, I tried speedtest.net, which ranks fairly high when one searches for “bandwidth test” on various search engines. I was getting very strange results, so I started wondering if my ISP might be bandwidth-throttling all traffic except the one from speedtest.net tests. After all, that’s on a 3G network, and another french 3G ISP (SFR) apparently uses Citrix ByteMobile to optimize the QoE by minifying HTML pages and recompressing images on-the-fly (amongst other things).
So, I fired wireshark, and discovered that no, it’s just speedtest being a bit naive. Speedtest uses its own text-based protocol on port 8080. Here is an excerpt of a download speed test:
> HI
< HELLO 2.1 2013-08-14.01
> DOWNLOAD 1000000
<Â DOWNLOADÂ JABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFG
Yeah, right: sequences of “ABCDEFGHIJ”. How course, extremely easy to compress, which apparently happens transparently on 3G (or is it PPP? but I tried to disable PPP compression, and it did not see any change).
It’s funny how digging into problems that look promising at first sight often results in big disappointments :-(
I tend to use and recommend testmy.net, which uses large blocks of random data.
Vodaphone also use ByteMobile. I understand that in Europe it can be disabled on request (1.2.3.50/ups/ or http://accelerator.t-mobile.co.uk/), here in Australia the javascript injection (http://1.2.3.4/bmi-int-js/bmi.js) can be disabled by:-
;in page code
bmi_SafeAddOnload= function() {};
OR
if (‘bmi_SafeAddOnload’ in window) {
var el= document.createElement(‘div’);
el.style.border= ‘dashed red 2px’;
el.appendChild(document.createTextNode(
‘Warning. Your wireless ISP is using a crap image recompression system ‘+
‘that will make pictures look like mud and which may stop this site ‘+
‘from working, and removes metatags. There may be a way for you to ‘+
‘disable this feature. Please see your internet provider account ‘+
‘settings, or try using the HTTPS version of this site.’
));
document.body.insertBefore(el, document.body.firstChild);
}
; at the server
Header merge Cache-Control no-transform
; or in the browser by manipulating headers (using an Iceweasel extension).
cache-control
no-transform
As for speed tests, I’ve tried a lot of them and IMHO the best Open ones are from MLabs:-
http://www.measurementlab.net/tools/ndt (requires java).
http://code.google.com/p/ndt/source/ (cli version)
A HTML5 version is being developed:-
http://code.google.com/p/ndt/source/detail?r=387&path=/trunk/HTML5-frontend/
Kind regards
Ref:- http://www.programmierer-forum.de/bmi-speedmanager-und-co-deaktivieren-als-webmaster-t292182.htm#3889392