Most phones will show you as "roaming" if you're off your providers cell towers. ie, I have a 2degree's SIM here in hamilton and it always shows that im roaming. Some phones let you disable data while roaming, is that what you're after?
Don't know about the iphone tho, surely it has something like that?
On the iphone up in the top left hand side in the title bar if your in the broadband zone it will show up with 2degrees if you are outside the zone it will show up with Voda nz
Edit: also they send you a text message when you move into a Vodafone sector. Which is starting to to get really annoying as I know when I am not in a broadband zone. when ever I go home for the night I get a text from 2 degrees
if you have purchased a broadband zone pack and haven't got a national pack they will lock you so that you can't use data outside of the broadband zones until you text 'unlock' to 233. that way you wont get charged the casual rate of 50c per Mb when roaming.
the reason they can't offer the packs everywhere is that they have to pay Vodafone when you are roaming, its just like the RED network for Vodafone DSL. You pay less when you are on a Vodafone DSLAM compared to being through Telecom wholesale.
Any posts are personal comments and not that of my employer
Thanks. I am at the airport and the network is showing as Voda NZ so looks like the iPhone is different to my old nokia which would show vodafonenz for a split second when it first turned on then changed to show 2degrees.