As far as i can see there are two gsm interfaces:
gprs0 - it is data transmission
phonet0 - I'm capturing something here when gprs connection is disabled and i'm getting or reciving sms (haven't try calls)

Wireshark is not recognizing the protocol, instead it identifies it as here http://wiki.wireshark.org/SLL
At info section there are 2 types of packets:
1)Unicast to us
2)Sent by us

and of course some hexadecimal value.
I'm guessing that it can see gsm probably encrypted packets (I have read that encryption is weak somewhere)

So do you have any idea how to make those packets more human-readable?