<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On 1 Feb 2012, at 17:33, Carlos Alvarez wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><br><br><div class="gmail_quote">On Wed, Feb 1, 2012 at 10:08 AM, Tim Bray <span dir="ltr"><<a href="mailto:tim@kooky.org">tim@kooky.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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9) Don't use low rate codecs. 711 all the way. Or 722.<br>
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</blockquote></div><div><br></div>I completely disagree. Most of our customers are on g729 and nobody was able to hear the difference when we tested that versus 711.<br clear="all"></blockquote><br></div><div>I think it is a bit different in Europe. People are used to really good phone lines which are always g711a all the way. All trunks have been digital for 30 years or more.</div><div><br></div><div>People can't put their finger on the difference on 729, but they know it is there. </div><div><br></div><div><br></div><div>In the UK many telemarketing calls are delivered from India to the UK using G.729 and G.723. There is a badge on the call (the sound of background call centre noise encoded) which makes you think you are about to have your life wasted.</div><div><br></div><div><br></div><div>My belief is that g729 calls last longer than g711 calls. I also believe that people ask for more clarifications. They say 'Can you repeat that?', 'Can you spell that please?', 'Sorry I missed that.' more often.</div><div><br></div><div>It would be an interesting thing to pull the data on or some some proper research.</div><div><br></div><div>In the early days of Skype I used to watch people come off a call and say 'That call was really hard work'. I think Skype have improved their systems since though.</div><div><br></div><div>I'm just into things sounding good. There was a time I could answer a call and tell you which VoIP provider the call came from. Some had a distinctive sound.</div><div><br></div><div><br></div><div>Tim</div><br></body></html>