What happen if full line?

Hi all.
I have a voice system that have a server, a Sangoma E1 card A104d QUAD T1/E1, 4 E1 connect to my card, and my server have installed Asterisk 1.4.18.
As i known, each port (E1) has 30 channel so my card has 120 channels.
I want to ask that what happens if there is more than 120 calls to my system ?
and Is there a way that we can handle more than 120 call without buying another Sangoma card ?

thank you very much.

I guess you certainly need to buy another E1 card to handle more calls.

If you are trying to generate more than 120 calls with only Quad E1 card (120 channels) system will not allow you to do so. Calls wil be dropped.