At 05:36 PM 11/21/2007, Ted Hardie wrote:
At 4:18 PM -0600 11/21/07, James M. Polk wrote:
>\
>Ted -- This header parameter is for a PIDF-LO, yes -- but it
pertains to the SIP WG's expertise in knowing and agreeing with
SIP's ability to foresee the type of topology from UAC to UAS, and
each server (whether there even is one) in between. I'm not so
sure the SIP WG agrees that a UAC can make this determination, and
am soliciting their input here in a broad way.
>
>Can a UAC understand enough about the topology of the Internet to
understand where it is sending a request, including how SIP servers
may or may not act upon that request?
>
>I believe, if the answer is no, the the "recipient=" parameter is
a flawed SIP header parameter.
>
>If the answer is yes, then it stays with no further arguments from me.
I think we have fundamentally different ideas of how much understanding of the
topology this implies. My view is that the header as currently specified says
either "This is meant for the person answering the call/taking the session" or
"This is meant to help get the call through/get the session to the
right responder".
Within the latter case, it requires no knowledge at all of topology; it does
not distinguish among the many different routing elements which might be
trying to make that happen.
A UA that does not care whether it is used for routing can enter "both"
and all is well. A UA that *wants* it to be used this way can enter
"routing-entity".
The availability of "endpoint" as a separate possibility makes sure that
an endpoint can indicate that use by the routing system is not intended.
I think this is what we disagree about. Aside the emergency
scenario, it is there types of requests that I find it a little hard
to believe a UA will know that a "routing-entity" will not be needed
to get the message to the ultimate UAS. How can the UA logic know
that when calling Pizza Hut or a specific verses nearest garage needs
to have location used or not?
This almost makes a practical use of this parameter (and this
RFC(to-be) to RECOMMENDED that "recipient=both" is the default unless
the UAC _knows_ it doesn't want a server ("routing-entity") to view
the location.
If the SIP community believes "routing-entity" is too vague
and needs to be broken out, I do not see how the GeoPRIV could object or
why it would want to; certainly this working group should have the final word
on that. But collapsing things so that entering "endpoint" is
not an indicator to the routing entities that they should just pass
things along
would find opposition (at the very least from me). That would break a pretty
fundamental assumption that users are in control of the pidf-lo distributions.
Hope you have a great Thanksgiving,
Ted
_______________________________________________
Sip mailing list https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [EMAIL PROTECTED] for questions on current sip
Use [EMAIL PROTECTED] for new developments on the application of sip
