Question : activating call forwarding on busy on an ISDN Line with mISDN

Hello,

I use a Beronet 4 ports BRI card with Asterisk and mISDN. Everything works fine except this. I have 2 ISDN lines, every line can handle 2 calls at the same time. So, my plan is to automatically forward the calls incoming on the first line to the second line if the the first line is busy.

I am in Belgium and my provider is the national operator (Belgacom).

To realise this, as stated in my ISDN line manual, I do the following combination *67*#. I get a special tone, so I guess this part is working.

To make my tests, I use 3 mobile phones. When the third rings, here is the log :
P[ 2] --> Call Waiting on PMP sending RELEASE_COMPLETE P[ 2] GOT IGNORE SETUP P[ 2] CC_RELEASE_COMPLETE|CONFIRM [TE]

Then, I try to change my misdn.conf to "max_incoming=4" (in place of 2), I get then :
P[ 2] Jitterbuffer Underrun. Got 18 of expected 128 P[ 2] handle_frm: frm->addr:42000203 frm->prim:3f082 P[ 2] channel with stid:10010200 in use!
P[ 2] channel with stid:10020200 in use!
P[ 2] channel with stid:0 not in use!
P[ 2] handle_frm: frm->addr:42000203 frm->prim:30582 P[ 2] set_channel: bc->channel:0 channel:0 P[ 2] NO USERUESRINFO P[ 2] find_free_chan: req_chan:0 P[ 2] !! NO FREE CHAN IN STACK P[ 2] lib Got Prim: Addr 42000203 prim 30582 dinfo 40142
(...)

The third mobile get a normal ringing tone or a message from the provider telling the line is not reachable.

As I understand, he tries to use 3 channels on a line which can handle 2. I think my D channel should send the information to my provider that the line is busy, so call would be forwarded to the second line.

Any clue on how to achieve this?

What I tried:
exten => _0.,n,misdn_facility(calldeflect,081XXXXXXX) => get a "Decoding FACILITY failed! (-1)" error in Cli
exten => _0.,n,busy =>do nothing
exten => _0.,n,hangup(17)  =>do nothing (17 supposed to send "busy" error)

Maybe it is something specific to my provider (Belgacom), so, what should already help, is giving me something which works somewhere.

Thank you in advance.

Answer : activating call forwarding on busy on an ISDN Line with mISDN

Try to make an mISDN trace of the calls. When a call is correctly established, your provider should mark the channel as busy and don't send any other SETUP messages for that line. With the trace you will see if this is the case (which would mean that your provider is not detecting the correct establishment of the call, or even show you that the call is not being correctly established at all)

You could add these options to the [general] section of your misdn.conf:
debug=2

tracefile=/var/log/asterisk/misdn.trace

And then simulate your problem.