[Asterisk-Users] Help with Understanding CODEC

[Nitesh Divecha]

Hello All, 
 
Need some small help understanding the CODEC part of Asterisk and my
endpoints. 
 
All my endpoints are Snom IP Phone and they come with G711a/u and G729A.  
 
So far I got mix messages from people that if your endpoints got G729A or
G723 codec already, I don't need to buy any licensing for the CODECS. 
 
But my question is "What about the server it self?" Because if I set my
priorities in the "sip.conf" file to use G723, G729 and rest disallow=all,
the voice stops working.  
 
So in short I do need licensing for G723 and G729 to be installed on the
Asterisk box it self? And how many do I need? 
 
Please help! 
 
Neel