It seems to be possible to set a timeout value when doing an Ajax request in plain javascript. see How to detect timeout on an AJAX (XmlHttpRequest) call in the browser?
It is also possible when using jQuery's ajax implementation, & other similar frameworks I assume. see Set timeout for ajax (jQuery)
Browsers seem to have rather vague specification regarding their default timeout. see Browser Timeouts
Hence one might "hey, I'm going to set a timeout to my ajax request so all the users will have the same timeout".
But then, the next question follow: would it actually override the browser's timeout in all cases?
When I say "all" cases, I mean for instance, if the browser timeout value is smaller than your ajax request timeout value.
I suspect it does not.
And I also suspect it is best practice to always have a timeout error handler to make sure that whatever happens you can display a relevant message that will save hours of work to your support team, & money to your company. see Determine if $.ajax error is a timeout
Thanks in advance