VoIP Mailing List Archives

[max.bridgewater at gma...]

Guys,

This question might be a bit off-topic, so please bear with me as i could hardly find a better place to solicit some help.
I suspect caller authentication can be challenging in the broader context of VoIP/SIP. Now, if we restrict the set of calls to those coming from the GSM network, is there a way to tell if the Caller Id is coming from the right source?  It doesn't need to be a bulletproofed solution. For instance, if i can already say that a given call is certainly coming from a GSM network (and that the call metadata weren't tampered with), i could maybe rely on the GSM authentication mechanism.

Any idea?
Max.

[dave at 3c.co.uk]

Hi Max,

I think that the answer is generally no - for example, I'm trivially
easily able to place a call to my GSM phone with any CLI that I choose.
If you can work around that, then consider the case where I divert my
GSM phone to you - the call to you will come from the GSM network, but I
can still set an arbitrary CLI.

Cheers --

Dave