If the service is paid up, there will be a ringing sound on the line. It doesn't matter if the receiving phone is online or not. I don't know how the messaging service determines if a phone is active.

If that was the plane detected over the Straight of Malacca, it would have been heading WSW. The only thing reachable near that route is Sri Lanka. The next landmass is North Africa, roughly a 1000 Km longer distance from point last seen then to Bejing. This is shaping up to be a Tom Clancy novel.
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Hope for the best and prepare for the worst.

The object in life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane