[Asterisk-Users] VoIP hackers gut Caller ID

[Steve Kennedy]

On Wed, Jul 07, 2004 at 07:57:36AM -0800, rich allen wrote:

> this is really simple, companies like Nortel, Lucent need to change 
> their code for caller id, if the number should be blocked then dont 
> transmit it to the far end switch

Err, not quite right.

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).


Steve

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