Multiple lines

Alright simple question I am sure…

I have an asterisknow setup all updated and running great!!! I am using broadvoice as my provider and so far they have been great as well, i have setup two trunks from broad voice both work.

Here is my issue. If a person calls the same trunk at the same time or near the same time the first one gets thru but the second goes straight to voicemail. In most pbx setups it would roll over to the next line available and ring that line. How do I set that up to do that…