[Asterisk-Users] Confused on G723 and G729

[Matt]

I see that G723 and G729 require a license to be used, or can be used
(in the case of G723) in pass-through mode only.

My question is.. if my voip terminator supports G723 and G729 only, do
I still need a license?  Or is that considered "pass-through"?  If so,
do I need to do anything special to get it to work?

I'm also a litle confused about why G723 can do pass-through but can't
do voicemail access?  What's the difference, or the logic behind this?