[niteriderxp]

If you use Dial Up Networking (DUN) to connect to the internet on your phone, you are more likely to transmit the DUN NAI when you authenticate. If they see you authenticate using your DUN NAI, they can charge you for it.

I did this a few years ago and to ensure I wasn't detectable I would change the DUN NAI in EPST to match the regular NAI. That being said Bluetooth DUN should work without any additional software if the DUN NAI has been changed. It will also give you a non-NATed public IP.

An annoyance that I have had with DUN is that you have to turn off all internet bound applications including Activesync before you dial up, otherwise they tend to disconnect your session.

In terms of VPN, I use PPTP to connect to work and never had any issues with it over ICS. Now if your company uses IPSEC, the protocol is a bit more complex and does not like traversing NAT.