International roaming plans from foreign carriers effectively bypass China's Great Firewall, making unfettered internet access seamless for visitors who use them.
Nathan explains that international roaming bypasses the Great Firewall because traffic routes through the visitor's home carrier before reaching the open internet, and his experience confirmed it worked flawlessly throughout the trip.
transcript
Nathan: And really in today's world, if you have a cell connection, that's not really an issue at all. It seems that the great firewall is basically, I think by design, just really not an issue for foreigners who come in with the cell connection. And I'm not an expert in exactly how all this technology works under the hood, but my understanding is that when you go in with an international roaming plan, you are connected, of course, to the local cell tower with your phone, but that your traffic requests actually route back to your home carrier first. Then they get processed out to whatever websites or services you're trying to use and then they get routed back from your home carrier to the Chinese local carrier and finally to your phone. And so you're bypassing all of these content filters just based on the fact that you're there with an international roaming plan.