asterisk users - Oct 2012 - How to avoid automatic answer with callwaiting=yes on fxs channels?

I will make an example:
A is an fxs phone with callwaiting=yes in chan_dahdi.conf

X calls A. A answers.
Y calls A. A hears the call waiting tone.

Now if A hangs up before X, then A rings again (which is what I want).
BUT if X hangs up first, then A automatically answers Y without even 
ringing. Is there a way to avoid it? If X hangs up first I want A to 
hear the busy tone until it hangs up too. Then I want A to ring again. 
Otherwise if both A and X hang up at the same time there is no way to 
know what happened.

Thanks,
Niccol?
-- 
http://www.linuxsystems.it

It seems fixing this issue and [1] would require significant efforts: 
https://issues.asterisk.org/jira/browse/ASTERISK-20556

Too bad, it means DAHDI is a no way for me, I will have to switch to SIP 
DECTs :(

Niccol?

[1]http://asteriskfaqs.org/2012/10/09/asterisk-users/asterisk-sends-wrong-fxs-idle-hints.html

Il 08/10/2012 13:20, Niccol? Belli ha scritto:
> I will make an example:
> A is an fxs phone with callwaiting=yes in chan_dahdi.conf
>
> X calls A. A answers.
> Y calls A. A hears the call waiting tone.
>
> Now if A hangs up before X, then A rings again (which is what I want).
> BUT if X hangs up first, then A automatically answers Y without even
> ringing. Is there a way to avoid it? If X hangs up first I want A to
> hear the busy tone until it hangs up too. Then I want A to ring again.
> Otherwise if both A and X hang up at the same time there is no way to
> know what happened.
>
> Thanks,
> Niccol?
-- 
http://www.linuxsystems.it