Subject: RE: [Sipping] Use of P-Asserted

From: De Leo Walter <[email-masked]>
Date: Tue, 20 Apr 2004 10:20:15 -0300

Thank you for your answer. It is very useful to me to know your opinion.
More inline
Regards.

-----Mensaje original-----
De: Cullen Jennings [mailto:[email-masked]] 
Enviado el: Lunes, 19 de Abril de 2004 12:09 a.m.
Para: De Leo Walter
CC: [email-masked]'
Asunto: Re: [Sipping] Use of P-Asserted

Not sure I fully understand but I think what you are saying sounds like a
reasonable way to use it.

By UAC's in the trust domain I assume you mean GWs, Call Agents, and B2BUA,
that are trusted not IP Phones sitting on someone's desk. [WDL]  That's
correct. We are talking of Call Agents, GW and B2BUA service platforms.

On 4/16/04 7:38 AM, "De Leo Walter" <[email-masked]> wrote:

Cullen: 

I have one concern about a use of a P-Asserted Identity header that some
folks are using. It is, from my point of view out of the scope of RFC 3325,
but I think it is a reasonable use.  The use I am referring to is the
following:

Calls initiated by UACs inside the trust domain include the P-Asserted
Identity (they are part of the network who asserts the identity) header in
their own INVITEs.

I refer specifically to this scenario: 

Suppose a SIP an ingress Media Gateway Controller, a B2BUA Service Platform
and an egress MGC. 
Calls initiated (from the SIP viewpoint) by ingress MGC or B2BUA carry the
P-Asserted Identity header inserted by themselves. The egress Media Gateway
Controller maps allways the content of the P-Assertd Identity header to the
ANI field in corresponding ISUP message and the presentation restriction
information in the Privacy Header to the corresponding ISUP field.

So the egress MGC has always the same policy, INVITES which don't have a
P-Asserted Identity header are not trusted, and if they have one either it
comes from a UAC authenticated by a proxy in the Trust domain or it comes
from inside the Trust domain itself and are, hence, trusted. (I am asuming
the communication inside the trust domain is safe).

Do you see any problem in this use of P-Asserted Identity header. 

I write to you because you are co-author of RFC 3325. I hope not having
disturbed you with this question. I copy the sipping list just in case
someone else has seen this use of P-Asserted Identity header and has
something to say.

Best Regards. 

Walter D. De Leo