R: [Asterisk-Users] VoIP hackers gut Caller ID

[Manuel Wenger]

> hi...
> 
> here in Italy is almost impossible to set an
> invalid cid, if is out of your allowed space.
> ie. if you have X numbers on your PRI,
> you can only set one of these. nothing more.
> on bri you simply cannot do nothing.
> 
> just my 2 cents.


In Switzerland CLI is also impossible to spoof - by default. If you ask the BRI/PRI provider, and you have an ISDN connection with DDI, they enable "CLIP Special Arrangement", which allows to add a presentation number to the real CLI. So you can't really abuse of it, because your "real" number is always transmitted together with your "pretend-to-be CLI".

The advantage of this is that anyone can change his CLI, for example to make outgoing calls and show a 0800 number in the customer's cell phone. We use this feature in our company, because our customers know us by our 0800 number, not the "real" number hiding behind it.

The disadvantage is that not all networks accept presentation numbers, for example Orange Mobile. In this case, the caller's real CLI will be displayed instead of the presentation number.

If you get yourself an SS7 link that's a different story, but in this case you're supposed to be a "trusted entity", and you shall not spoof and play with numbers that you're not allowed to use. IMHO, trusted entities with SS7 links that abuse of that power should simply be disconnected from the public network. Not every kid with a couple $1000 spare should be allowed to play with this.

-Manuel


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