Hi,
before forwarding a call (INVITE) from the PSTN with flag "privacy=full" in the Remote-Party-ID hf to a none-voice-licensed carrier I need to make sure that the calling party number is completely wiped out from the SIP requests.
I see this number at three places: the Remote-Party-ID hf itself, the
From hf and the Contact hf.
The Remote-Party-ID hf can simply be dropped or replaced by something anonymous.
The From hf can be rewritten using uac_replace_from.
But what about the Contact hf? This field is, as far as I can see, required for routing purposes, to tell the called party side where to send replies. So, if I would manage it to rewrite the field, I would have to make sure, the replies sent to the rewritten address once again will be rewritten to target for the meant destination.
Is there a best practice for this item?
Thanks, Wolfgang
Hi,
you're right, but here the source is the GW and the destination is another SIP proxy with SIP phones behind it. And since we are terminating calls out of the PSTN to this other SIP proxy, ran by a company without voice-license, I need to remove any hint to the identity of the caller before handing over the call to that second SIP proxy.
Wolfgang
Bogdan-Andrei Iancu wrote:
Hi,
I see what you are trying to do. I have some idea about masking the contact hdr, but you still have to deal with VIA :D.....
about Contact...since the contact provided by the GW is the same (let's assume that), before forwarding to the foreign proxy, you may replace the GW contact with a contact pointing to your server and containing a token easy to recognize (maybe a username?). On the way back, if you find the funny contact you inserted (which will be RURI or Route), you have to restore it to the GW contact....
never tried this, but it might work....
regards, bogdan
Wolfgang Hottgenroth wrote:
Wolfgang,
usually there are two ways to go when you want to protect a GW: 1) make it invisible (want you are trying to do) 2) make it inaccessible = set it a private network, accessible only via the proxy; from outside, only private, unroutable/useless IPs will be visible ;)
basically the major factor is if you control the GW or not...
regards, bogdan
Wolfgang Hottgenroth wrote: