[asterisk-users] ISDN - Busy signal on 3rd call

[Paulo Santos]

Paulo Santos wrote:
> Hello,
> 
> Following my first mail about this issue [1], I think I know now what
> the problem is.
> 
> When I have both lines being used and a third call comes in, the person
> calling doesn't get a busy tone, he gets something like line unavailable.
> 
> I've been debugging mISDN and I think the reason is because asterisk is
> sending the release cause as 0.
> 
> 	P[ 3]  --> channel:0 mode:TE cause:0 ocause:0 rad: cad:
> 
> The request from the telephone company's switch seems correct, a SETUP
> message (if 08 is Q.931, 05 is SETUP).
> 
> 	02 ff 03 08  01 04 05 a1  04 03 80 90
> 	a3 18 01 80  6c 0b 01 83  39 31 36 33
> 	39 31 37 34  32 70 03 c1  38 34
> 
> I've changed misdn.conf so it sends a release cause as 17 (user busy),
> but I get the same behaviour - cause:0 ocause:0.
> 
> Anyone knows how can I force asterisk to send cause 16 or 17 in this
> situation?
> 
> Thanks in advance.
> 
> Best regards,
> Paulo Santos
> 
> misdn.conf: http://pastebin.com/FmgECqkU
> misdn debug: http://pastebin.com/Tg6wPKBD
> 
> [1]
> http://www.mail-archive.com/asterisk-users@lists.digium.com/msg244330.html
> 

Ok, I've encountered a similar issue on a different installation but
instead of being PTP it's PTMP. Plus, it's a setup with 2 BRI lines with
call forwarding between them - main number of BRI1 forwards to secondary
number of BRI2 when busy/unavailable and vice-versa.

I've called the phone company and confirmed that call waiting is
disabled, yet I get a message in misdn debug saying:

	P[ 2]  --> Call Waiting on PMP sending RELEASE_COMPLETE

I don't know if this is the actual call waiting feature or if it is just
an information of some kind.

In the misdn debug I get this: http://pastebin.com/D7wv0qqm

The P[ 2] is the port of the BRI line I called in the first place, then
it is forwarded to P[ 1] where I get an error:

	P[ 1] Decoding FACILITY failed! (-1)

And the same issue I said in the previews email:

	P[ 1]  --> channel:0 mode:TE cause:0 ocause:0 rad: cad:

I changed isdn_lib.c and now I'm sending ocause:17 (user busy). I've
done this in the PTP line mentioned in the previews email as well.

For the PTP line it appears to have worked, I have the regular busy
signal. It worked only after the first time I tried to place a 3rd call.
Now the 3rd call doesn't even reach Asterisk, which was what I wanted
from the phone company in the first place.

On the PTMP line it didn't work, I still don't get the busy signal.

Maybe cause 17 isn't the right one? And what can be that "FACILITY"
mentioned in the debug?

Thanks in advance.

Best regards,
Paulo Santos