Incoming line identity and ALS

[Denis Kenzior]

Hi Chris,

> > CDIP (like CLIP) is issued after every RING/CRING.  Whereas CLIP returns
> > the calling line identity, CDIP returns the called line identity (e.g.
> > the phone number the remote caller dialed.)  According to the
> > specification it is not reported for outbound calls.
>
> It seems that my phone doesn't support CDIP, although it does support
> line-2/ALS which is a bit odd. I'll investigate more on that..

Many Phase 2+ devices only supported ALS and the rest of the CPHS standards.  
CPHS was largely merged into the 3G GSM standards.  If you're interested, 
google Common PCN Handset Specification.  This is where ALS comes from.

>
> One thing I'm not certain about is whether CDIP would report which
> line received the call, or which number the calller dialed as they
> could be different. I know other areas deal with routing information,
> but I wasn't sure which which number CDIP reported. It would be great
> for ALS support if it were the line that received the call, rather
> than the number dialed by the caller.. though that could be
> interesting in other situations.

This is entirely up to the network.  The likely scenario is that the network 
will normalize the number according to the network's rules.  While this sounds 
nice, it can still lead to some ambiguities.  E.g. in the US the following 
numbers (as presented in CLIP) are equivalent:
"15556677", 129
"15556677", 145
"5556677",129

> I'll do more investigation and try and come back with something more
> constructive

Sounds good.

Regards,
-Denis