Tech question on TETHERING

Hello!

This is not the standard rumbling on how expensive tethering is gonna be
I was just wondering, how are operators able to detect you are using tethering and charge you accordingly.

Is it that the iphone connects to a different APN and thus tethering data goes thru a different server?

Anyone with the 3.0 GM or the developer seeds is able to check this out?

I'm just trying to think if it will be possible to by-pass this when you have a jailbroken iphone (since I use the tethering option using pdanet just once a month tops!!)

Thanks

 

the only way I can think of is switching APNs
well in fact I don't think there needs to be a switch at all.. I think phones can use several APNs at the same time.

for example, the APN for mms and for wap is different, and in my old phone I could use wap at the same time I was sending an MMS, meaning there were two sessions to two different APN.