> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Adam
> Roach
>
> Yes, the authors of RFC 3168 analyze what happens when a router is
> acting outside of specification, potentially with malice. But is TSV
> actively engaged in specifying how to duplicate information in a
> different part of the message in the hope that these non-conformant,
> potentially malicious intermediaries won't find it?
>
> No, they aren't. Because that would be patently ridiculous. Recognizing
> the potential for an attack doesn't necessarily force the definition of
> comically[1] ill-conceived and easily defeated countermeasures.
>
> Assume the draft on the table is published and implemented. How long
> before someone decides that their SBC "needs" to modify the
> "P-Original-To" header field? And when they do, will we just define
> another header field to squirrel away yet another copy of this
> information? (Should we go ahead and define "P-Original-P-Original-To"
> right now?)

This implies I'm trying to hide/tunnel the information from intermediaries to 
get around their policies.  I'm not.

SBC's (and others) modify the From/To URI for a bunch of reasons.  One of those 
reasons is relationship hiding, and for any such policy there is clearly no 
point in trying to avoid/bypass it, as they'll just go delete or modify any new 
headers as you point out.  There is nothing we can do for such cases, imho.

But for a lot of cases they're not modifying To/From for that reason - they're 
modifying it to either "fix" them for specific interop reasons, or to hide 
topology (ie, when it contains IP Addresses or hostnames).  Those are the cases 
I'm trying to get the information through.

-hadriel
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