[Asterisk-Users] G729 vs. gsm

[Steve Underwood]

Michael D Schelin wrote:

> I have used G729 and it sounds almost as good as G711U. The problem is 
> the way Asterisk uses it. It does not sound robotic and it's not 
> suppose  to sound that way. Most Carriers want the calls to be in 
> g711u so thats why I use G711u otherwise I want to save money on 
> bandwidth. G729 on Asterisk adds latency. this could be one of your 
> problems. Also you will not get music on hold to play well with G729.

G.729 doesn't sound that bad. However, if you find it hard to tell G.729 
from G.711, I think you should have your hearing checked. :-) It really 
doesn't help people to assess what is right for them, if other people 
make these exaggerated and unreasonable claims. Even the people 
promoting G.729 give it a MOS far below G.711. You are certainly right 
about music on hold, but even voice plus a little background noise can 
sound bloody awful through G.729. Its performance is *very* dependant on 
compressing just a single human voice.

Regards,
Steve