The T-mobile ONE plan gives you unlimited data while roaming in 140+ countries — for about $70 / month. It’s maybe more expensive than buying SIM cards in each individual country, but by reducing the amount of SIM card buying and swapping, it’s a pretty good value.
That’s pretty sweet, except… when we had a layover in Tokyo’s Narita airport, my international SMS and Voice worked, but not my Data.
The same thing happened in Hong Kong — SMS and Voice worked, but not Data.
I need Data!!!!
I called T-mobile support, and the agent walked me through everything, confirming my APN settings, and then we tried connecting manually to each of the specific mobile network operators in Hong Kong.