Is there a « standard » protocol for a device connected to a Wifi network to detect when the WAN/uplink connection is dead, and behave as if there was no Wifi at all?
Here is a use case I’m seing for such a protocol:
Given a mobile device that can do Wifi or 3G.
When the device is in the vicinity of a known (or open) Wifi network, it connects to it in order to get access to the Internet.
Now, if the DSL (or any other broadband access) connection on the Wifi router is dead, then my device can’t connect to the Internet, and it will stay connected to this Wifi network trying endlessly to get Internet connection through this Wifi router.
In these cases, the Dead-WAN-Detection protocol could instruct the device that the Internet/uplink connection is dead (although the Wifi connection is up), and the device could react by switching to 3G in order to get Internet connection.
Then, when the uplink connection get back on the Wifi router, the router could broadcast a signal indicating that the connection is up, and the device would then switch back from 3G to Wifi for its Internet connection.