[Asterisk-Users] TDM04B + Voicemail poor Quality

[Rich Adamson]

> Recently, I installed TDM04B 4 FXO card on to my Asterisk box and  
> installation went perfect.
> 
> The only problem I am facing is the Voice mail has very poor quality  
> when any users leave voice message via PSTN line.
> 
> We can not hear either from the extension nor from the WAV email  
> attached.
> 
> Has anyone experienced this problem before, please help?

Yes, its well known. See bug #2023 in the bug tracker.

Kevin would like to address this along with addressing missed frames
(common complaint when attempting to use spandsp) before the next
formal Stable release. But, its too early to guess whether that 
will actually happen (as of right now).