LR: VUgen web_set_timeout function unrealistic?

I understand that VUGen's web_set_timeout function allows me to set a timeout value higher than the usual value (which seems to be 120 seconds).

What I do not understand: Doesn't this imply that all users would have to set their browser http POST timeout config value to a new, higher value? Don't I then test with a (simulated/virtual) user configuration that no real-world user would/could use?

Wouldn't I also require all proxies between the user and the webserver to be configured with an at-least-as-high timeout value to use a custom timeout value in the browser? Otherwise my user's transactions will fail while my load test would pass?

Context: Load test of an browser- (Ajax) based frontend wi开发者_StackOverflow中文版th VUGen 9.51. Browser times out on web server request with Error -27728 Step download timeout (120 seconds) has expired when downloading non-resource(s), and I hesitate using the web_set_timeout fore obvious reasons.

Each browser has a different time-out value defined. This value can also be changed rather easily by users.

Have a look at http://support.microsoft.com/kb/181050 for info on IE timeouts.

In short it says:

Internet Explorer imposes a time-out limit for the server to return data. 
By default, the time-out limit is as follows:

Internet Explorer 4.0 and Internet Explorer 4.01    5 minutes
Internet Explorer 5.x and Internet Explorer 6.x    60 minutes
Internet Explorer 7 and Internet Explorer 8        60 minutes

Internet Explorer does not wait endlessly for the server to come
back with data when the server has a problem. 

Also many services that are used today are machine-to-machine services (othen SOAP requests are used for this) and they may have time-outs that are interface specific.

The place in VuGen where this is set from the UI is from the "Run-Time Settings | Preferences | Options" - in this list there are the following timeouts that can be set:

HTTP-Request connect timeout     default 120 seconds
HTTP-Request response timeout    default 120 seconds

In practice however, if a normal web-ui takes more than 5-10 seconds to respond to user clicks then the service will be considered slow by the users.

The exception here is SAP EP where 30+ minutes of waiting for simple thins is OK ... :)