inbound can be handled various ways

1.  you can create separate contexts similar to [gdincoming] that set a 
particular campaign (which you would create in dialeradmin, and assign 
agents too).

2.  you can point your DID's to [gdincoming] that will do a lookup against
all the existing campaign tables to find a match, if so it will set that 
campaign and use those members, OR, if it does not find a match, it will 
create an entry in the INBOUND table, and will search for members of the 
INBOUND campaign.