True, however when you're leaving the building, the most common case ought to be that you stop being able to ping the upstream router. Easy for the phone to fin

True, however when you're leaving the building, the most common case ought to be that you stop being able to ping the upstream router. Easy for the phone to find out, since single-hop ICMP doesn't need a long timeout. There are other possible failure modes, of course, but fixing the common case has value.