wispr xml, WiFi Auto-Join feature

Hallo,

do anyone knowing how the feature "Auto-Join" within a WiFi profile exactly work?

I Know already following things:

Apple check with the Agent "CaptiveNetworkSupport-173 wispr" following URL "http://www.apple.com/library/test/success.html", If a "success" Text will removed the device knows: "I have free Internet Access"

If no "success" text comes back, the device knows, there is a Landing Page from a HSIA Provider between iphone and Internet and a Webauthentication take place.

The Landing Page will be opened in a separate window (not safari App) whrere the user type in its login credentials.

I have read in another Apple Guide the login credentials will be cached by the feature. In this case the user doesn't have to type in the credentials one more time.

In some tests with an HP MSM Controller (HSIA Gateway) this was not take place.

I need a detailed technical description of this feature...

Very thanks for you help!

Regards René