Steve Underwood wrote:

Depends what you are after. Speex offers the quality of G.729 at around 
the same processing load. However, nobody seems to want to pay for the 
processing load of G.729. Almost everything uses G.729A. Half the 
processing load, but significantly poorer quality.

VoIP is mostly a race to the bottom, and people wonder why it makes no 
money for provides. :-\

And, at the wholesale level, it makes no sense whatsoever to compress calls
any more: bandwidth is so cheap (and has been for a while) that the loss in
call quality - especially from tandem compressions - and the increased
processing requirements and other bits of expense do not stack up. Case in
point: we moved a route from G.711 to G.729, and saw the ACD drop from
over 10 to under 7 minutes. It was a route to mobiles, so the audio was being
recompressed with the GSM codec on its way to the handsets. Economically,
had we carried on using G.729, we'd have lost about 30% of our margin on
that route.

--Dave

-- 
David Knell, Director, 3C Limited
T: 020 8114 5002  F: 020 3002 7257  M: 07773 800623
http://www.3c.co.uk