It might be different if you're already inside the network. My understanding of one provider's 3G network is that it assigns everyone a 10.x.x.x private address, then has several layers of NAT to get to the outside world. That precludes any incoming connections from the internet, but it doesn't necessarily stop one device connecting to another internal to the 10.x.x.x network.
Posted Nov 11, 2009 23:45 UTC (Wed) by drag (subscriber, #31333)
[Link]
You could still have people reach you if your running a tunnel to a external
server.
But remember that the iPhone has Wifi capabilities and like most consumer
mobile devices it will probably happily latch itself to any network that
presents itself to the phone.