[asterisk-biz] Overhead for g.729

Hey Folks..I know this is a simple question, so I apologize. 

I'm trying to spec out how many concurrent calls we can do w/Asterisk on a Meg of bandwidth w/SIP and G.729.  My developer is tell me G729 will use 32 Kbps.   Could that be correct? The codec only takes 8k.  Is there that much overhead.

Thanks for your patience with this!!

Chip

Chip Greenberg