[asterisk-users] twice normal beep before busy tone ??

Eric "ManxPower" Wieling eric at fnords.org
Thu Nov 6 09:54:44 CST 2008

It sounds like you have analog lines.  If that is the case, the silence 
you experience is Asterisk sending the DTMF down the line.  Asterisk 
collects the DTMF and when you are done dialing it retransmits those 
digits down the analog line.  I think each digit is by default 300ms. 
If you are dialing 10 digits you have a delay of 3.3 seconds while 
Asterisk is sending the DTMF.  None of the VoIP protocols have his 
issue.  ISDN PRI or BRI also does not have this issue.

Stefan Guenther wrote:
> Matt wrote:
> ------------------------------
>  >What this means is that if the call is busy, it will play busy tones,
>  >if the call is ringing it will play ringing, congestion, congestion
>  >etc.
>  >
>  >The reason you are hearing silence is that Asterisk doesn't know what
>  >the status of the call is before that.
>  >The cell phone provider will likely take up to 3 seconds to tell your
>  >machine what is happening with the call.
>  >If you use the 'r' option then it will play ringing tones even if the
>  >phone is busy.
>  >
> well that means, that if I have a "bad" phone line (meaning poor 
> quality) and I remove the "r", I will definitely have silence, when I 
> call cell phone numbers and may have silence on calls to normal phones.
> If I leave the "r" in the dial string, this removes the silence and adds 
> the ring tone, with the disadvantage that I will even hear the ring tone 
> on calls to busy numbers.
> If that is true, the whole problem is related to the quality of the 
> phone line, which prevents asterisk from getting the right status fast 
> enough.
> Regards,
> Stefan

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