Those tiered captive portals have unique requirements that conflict with OS behavior:
A) By default, they want to offer some limited Internet access, such as accessing a sponsored site (often a shopping site like Amazon) or streaming videos (from some server on the airplane LAN).
B) For premium, paying users, they want to offer (mostly) full Internet access
For this to work, they have to fool devices in Tier A into believing that they have Internet access, by spoofing responses from standard captive portal detection URLs like captive.apple.com. Otherwise, if the network fails the captive portal test, many devices won’t stay connected to the Wi-Fi network, preventing access to the sponsored sites or LAN streaming apps.
At the same time, they want users to be able to upgrade from Tier A (limited access) to Tier B (full access) at any time. So they enable these upgrades by serving a captive portal page... to every HTTP site _except_ the standard OS captive portal detection pages that would affect OS behavior.
That’s when the user needs to visit an HTTP site other than the standard captive portal pages. One like neverssl.com
It’s obviously a fragile solution and is becoming an increasingly poor experience as sites adopt HTTPS, HSTS, and other standards. At the same time, I don’t know of any upcoming solutions to the tiered captive portal problem. Does anyone know what should replace this?
