TCP is the standard data carrier of your network...
So your Nobex radio (I've never used the app so I'm just assuming here) will give you the choice to connect through BIS or TCP...BIS uses the encrypted data carrier through RIMs servers, where-as TCP is a "direct line" to the operators data service.
Anyway, you need to get hold of some APN settings from your carrier... or google "Vodafone [insert country here] APN settings"
and enter what it says into options -> advanced -> TCP