Summary:ASTERISK-15178: G723 codec has digitzed voice
Reporter:Scott Johnson (globalnetinc)Labels:
Date Opened:2009-11-19 20:04:52.000-0600Date Closed:2011-06-07 14:00:27
Versions:Frequency of
Description:I am using an audiocodes mp202b asterisk and a digium tc400b.  When I call the asterisk box and get prompts all sounds well.  When asterisk has to bridge the 723 rtp stream to ulaw for the sip provider the voive becomes very digitzed and poor.

mp202b(723)=> asterisk - works.
mp202b(723)=> asterisk(ulaw)=> sip provider - fails

it produces poor quailty both ways
Comments:By: Leif Madsen (lmadsen) 2009-11-19 21:11:05.000-0600

Please provide some additional information that would allow us to actually debug this issue.

By: Scott Johnson (globalnetinc) 2009-11-20 09:25:14.000-0600

do not know what addtitional info you would need.  this happens 100% of the time using these components.

audiocodes mp202b using g723 in either low or high bit rate
asterisk with tc400b transcoder
sip provider using ulaw

I have also verified it byt using another asterisk box and using ulaw between them.  the voice is digitized.  acts like the problem that was just solved for me on g726.

what would you like for info?

By: David Woolley (davidw) 2009-11-23 06:20:02.000-0600

For a start, what do you mean by "digitised", as all speech is digitised on Asterisk (and most public telephone networks).

I would have thought that the correct place for support for the tc400b would be Digium's commercial support channels.

You actually meant G.723.1, not G.723.  That appears to be a rather low bit rate vocoder codec so it should sound somewhat machine like, especially if you are using the 5.3kb/s variant.  GSM, also a vocoder system, uses more than 13kb/s.  There is a half-rate GSM, but I believe most people think the sound quality unacceptable.

By: Scott Johnson (globalnetinc) 2009-11-23 11:34:00.000-0600

Assuming I am not a complete idiot, I understand all voice on a VoIP system has been digitized.  This codec is being done incorrectly.  The audio quality is not understandable.  the problem is much like the g726 problem I submitted.  You may want yo take a look at 15504 which was eventually closed by 16230.

By: Leif Madsen (lmadsen) 2009-12-21 10:11:21.000-0600

Per kpfleming, this appears to be a Digium support issue with the TC400B board, so I'm going to close this issue and encourage you to contact Digium support. Sorry for the delay here, as I didn't clue in this was likely a commercial support issue.