[asterisk-users] Dahdi/callerid issue

[Gordon Henderson]

On Mon, 18 Jan 2010, evert at disruptor.nl wrote:

> Hi All,
>
> Maybe someone knows this, im using dahdi in combination with a TDM400,
> where 2 analog PSTN lines are connected.
> The weird thing is tho that when someone calls the analog lines it goes
> perfectly fine, the line comes in and all works ok.
> Except:
> Sometimes the callerid from the caller is not the complete number, but
> only a few random numbers from that phonenumber, and sometimes its
> complete.
> My personal guess its something with the timing or so, but no clue exactly
> where to look on that part.
>
> The versions im using:
>
> Asterisk 1.6.1.12
> Dahdi 2.2.0.2
> \-- Echo Cancelling engine: MG2
>
> Maybe someone has an idea, i really dont atm.
> Its btw a dutch phoneline.

Dutch caller ID - it's weird. Seems to be transmitted in DTMF before the 
line rings, so answering it isn't going to help at all, and by the time 
you get the ring, it's too late anyway.

I can't find anything definitive (and am not going to look more), but 
searching found this:

   http://www.ainslie.org.uk/callerid/cli_faq.htm

which led to this - which is for the Danish system, but it suggests it's 
not too different from the Dutch system.

   http://www.blichfeldt.dk/faq/clip.htm

   "The Danish implementation of CLIP uses simple DTMF-signalling,
   transmitting the A-subscriber number (from the exchange) to the
   B-subscriber, just before ringing."

I'd start by looking at the configs and making sure you have the correct 
settings in the configs to make sure the line impedances, etc. are set 
right for you.

E.G. in the UK, I want to see that my FXS device is using UK signalling 
and the way I do it is by putting

   options wctdm opermode=UK

in a file in /etc/modprobe.d and setting the right values in 
/etc/dahdi/system.conf:

   loadzone=uk
   defaultzone=uk

Work out what's right for .nl and it'll be a good start.

Gordon