check with the Operator if you BB data plan includes the blackberry.net APN access only or it implies the usage of WAP APN usage as well.
if you can use blackberry APN only - it implies usage of
- BB service
- browsing (through BB Internet browser only)
- Instant messaging
- facebook and twitter apps usage
- some other things that go through blackberry.net only
Streaming is not included in blackberry.net APN, which means you have to have an additional source of data usage (for WAP/Internet usage).