[Asterisk-Users] Cisco ATA Advanced CallerID

Armand A. Verstappen armand at nl.envida.net
Thu Jul 24 14:12:49 MST 2003


Hi Pauline,

On Thu, 2003-07-24 at 22:21, Pauline Middelink wrote:
> > > The Gesko Ikarus 1200S analog telephone has advanced callerid
> > > capabilities. When used with an ATA186, it show the username
> > > and the phonenumber of the caller. (or whatever you let *
> > > tell it)
> > > 	http://www.gesko.be/idgg004.htm

> > Thank you for the pointer. From the quick glance I got, it supports
> > dutch (DTMF style) CLIP, and the newer CNIP to receive the name part. Do
> > you happen to know if this phone is switchable to FSK signalling? I did
> > not see the tell tale trace 'also works on UPC cable phone network' in
> > the add.
> 
> Well, since the ATA we are using is in default mode (US, hence FSK)
> I presume the phone can do FSK.

makes sense.

> Looking at the bits in the ATA, I only see sizes for number and text
> on the FSK mode setting, on DTMF it only has a number length. Can I
> conclude from this limited data that DTMF can't do text?

Yes, you are correct. CLIP only presents the number of the caller. it
uses DTMF based signalling.

I'm playing with a devkit, split up over two installations:

(analog) PSTN---X100P---asterisk---Quicknet----analog phone

(isdn)   PSTN---Fritz!Card---asterisk---TDM40B---analog phone

now, on the analog side, I don't get the caller-id, because it is sent
as CLIP-DTMF, and asterisk is looking for FSK. on the isdn installation
I do get the caller id information (again, numeric only) from PSTN,
using either isdn4linux or chan_capi, but on the analog phone, I don't
get this callerid passed on, because the phone is looking for CLIP-DTMF,
but receives FSK from the TDM40B.
Because UPC uses FSK-signalling on their cable phone service, there are
some phones available in the Netherlands that are usable with asterisk.
It's just limiting the number of phones that can be used. The problem
with the X100P not being able to pick up caller-id can only be solved if
the hardware and drivers have certain capabilities, and the software is
capable of recognizing the CLIP information sent. 

I'm not sure if the X100P and TDM40B hardware is capable of detecting /
sending polarity switch. This is what is used in DTMF-CLIP to signal
that caller-id info is coming, it is sent _before_ the first ring.

The Number info is then sent as DTMF <D><num-1><num-2>...<num-n><C>.
There's a number of countries that use basically the same protocol, but
some use <A> and <#> for start and end signalling, and other variants.

> Now all i have to figure out is how to confince the ATA to sent the
> callerid BEFORE the first ring instead of between rings, because i'm
> so close to the phone, i pick it up in the first ring and than the
> display has no name.. :(

That sounds like FSK indeed. DTMF CLIP sends it information before the
first ring. 

Funny thing about the DTMF-CLIP spec is that the first ring will be sent
_after_ sending the caller-id info, but that transmission of caller-id
is to be aborted if a call is answered before sending is complete... ;-)

>     Met vriendelijke groet,
    ...en aan eenieder die mij een warm hart toedraagt
      _geen_ stomp in de maagstreek ;-)

-- 
Envida                     http://www.envida.net/
Armand A. Verstappen       Graadt van Roggenweg 328
armand at nl.envida.net       3531 AH Utrecht
tel: +31 (0)30 298 2255    Postbus 19127
fax: +31 (0)30 298 2111    3501 DC Utrecht
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