[Asterisk-Users] RE: Caller ID

[Gavin Hamill]

On Monday 03 May 2004 00:02, Paul Crick wrote:

> Hmm.. but wouldn't reversal detection help those people who are in the UK
> and want to receive caller ID?

Yes and no. If we could leave the FSK modem running all the time, then 
hardware support for the polarity switch wouldn't be as vital.

> www.sinet.bt.com

Aye, I've poked through that and changed some of the Hz values in callerid.c, 
but it's getting the code triggered that's the tricky bit! :)

> I bow to the greater knowledge of the true techies on the list.. 

Me too! :)

> I guess European caller ID is one of those big problems, with lots 
> of countries using lots of different protocols - I think some scandinavian
> countries even use on-hook DTMF..

I've been looking through the Asterisk source today a lot, and the actual 
problem with UK CLID seems to be * was designed solely for the USA model of 
"once we get a ring, despatch a new thread to listen for CLID".

So, yes if it were possible to detect the polarity switch, that would be 
enough to trigger a 'ring' event in *, and then the CLID code could 
trigger :)

> Easy answer: Get a digital circuit! :-)

:) You ain't experienced the danger of me with a soldering iron :)

gdh