asterisk users - Dec 2005 - Sipura 3000 Call waiting on the PSTN line

I have configured my SPA-3000 to direct all calls received over PSTN
interface to Asterisk. That is set up via a dial plan with S0 and works
fine. CID information is passed along as well. But I find it impossible
to setup call waiting on the PSTN line. I do subscribe to this service
from my PSTN provider (SBC). Once a PSTN call comes in, is forwarded to
asterisk and then to a phone at line 1, Sipura seems oblivious to any
other calls coming in on PSTN. When I dial my PSTN number with a second
call I don't see any activity on Sipura. I have set up remote logging
and the level is set to 3. But I still get no activity in the log for
the second call. Even the first call logs very little, but it logs
something. Has anybody been able to get call waiting on the PSTN line? 

Thanks,
Chip

> Has anybody been able to get call waiting on the PSTN line?
As far as I recall, you will only hear a tone in the audio stream when
a second call comes in. The Sipura does not detect or handle it, but
if you flash the line on the FXS interface after hearing the tone, the
Sipura will forward the flash to the FXO interface and hence switch to
the second call. I am positive this works when the call is picked up
on the local FXS port but I am not sure if it also works when the call
is picked up by a remote device.

This is how I had set it up:
PSTN -> FXO on Sipura 3K -> Asterisk (remote via DSL) -> FXS on Sipura
3K -> Phone

The call would be re-invited in this case so no RTP traffic goes via
DSL, only SIP traffic. Switching to second call with flash works in
this scenario. Additionally I also allowed the call to be received by
a remote device (RTP via DSL) but I am not sure if you can then use
Call Waiting (never tried it).

I don't think I'm expressing myself clearly here; if not, please ask.
Or correct me if I'm wrong.

Luki

cp wrote:
> I have configured my SPA-3000 to direct all calls received over PSTN
> interface to Asterisk. That is set up via a dial plan with S0 and works
> fine. CID information is passed along as well. But I find it impossible
> to setup call waiting on the PSTN line. I do subscribe to this service
> from my PSTN provider (SBC). Once a PSTN call comes in, is forwarded to
> asterisk and then to a phone at line 1, Sipura seems oblivious to any
> other calls coming in on PSTN. When I dial my PSTN number with a second
> call I don't see any activity on Sipura. I have set up remote logging
> and the level is set to 3. But I still get no activity in the log for
> the second call. Even the first call logs very little, but it logs
> something. Has anybody been able to get call waiting on the PSTN line? 
> 
The syslog feature in the spa3k does not take affect until after the 
spa3k has been power cycled. It's not a dynamic parameter change like 
most of the other config parameters are.

See other post on the call waiting topic.