[Asterisk-Users] VoIP hackers gut Caller ID

[Alan Laird]

Steve Kennedy wrote:

>There are a few circumstances when called ID can be blocked (it's
>rumoured certain spook agencies have this ability), however if a "user"
>withholds CID, then it's just flagged at the local switch and passed
>switch to switch with the withold CLI flag. The terminating switch
>should then NOT pass on CLI if the withold flag is set on to an end-user
>line.
>
>Of course some agencies will get CLI passed even if the withold flag is
>set (in the UK, Police, fire, etc, potentially even ISPs for abuse
>purposes - but they are not meant to abuse the privilige).
>
>  
>
IIRC this is two distinct cases.  CID (by various names) is whatever the 
originating party (customer) wants to say it is in the case of a PRI.  
ANI is correctly populated at the RBOC when the call enters the SS7 
fabric.  This means that no matter what I stick in the CID field, a call 
to 911 will pull up the correct address based on ANI.

In my config I manipulate the outbound appearance for a variety of 
reasons and use 9, 99, 8, or 88 prefixing the outbound call to allow the 
user to control their call appearance.  This allows various classes of 
calls to have a useful number in case the person you called wants to 
return your call and go directly to your station or the correct call 
queue.  For example, when someone outcalls from the credit card 
verifications team the CID will allow the person called to return their 
call and bypass the IVR prompting.

Then again...  I probably have no idea what I'm talking about.

Alan