Re: Communication means in draft-ietf-impp-cpim-pidf-05

Paul Kyzivat <[email protected]> wrote on 09/08/2002 19:12:11:

> Mark Day wrote:
> > 
> > I think the relevant point for interoperability is that 
implementations
> > should avoid assuming that another party splits presentities/tuples in 
the
> > same way. For example, it's perfectly reasonable for the user agents 
of one
> > system to display presentities as "people" and tuples as "devices" 
while the
> > user agents of another system displays presentities as "people's 
devices"
> > and suppresses tuples (since maybe each presentity only ever sends 
one).
> 
> I'm with you this far.
> 
> > But if those systems are interoperating, it would be bad if they 
applied
> > those same display techniques to the information received from the 
other
> > system.
> 
> How could they do otherwise? The act of inserting a gateway 
> between the two systems doesn't change the behavior of the other 
> components of those systems. Or are you saying that as part of 
> establishing interoperation, each system must enhance its 
> intrinsic model to embrace the concepts of the other? That seems 
> much less likely to happen than the installation of gateways.

In order to support an IMPP compliant gateway, a system has to be aware 
that IMPP employs a two level hierarchy of presentity and tuple. A system 
that employs an identical two level scheme will have no problem mapping 
to/from IMPP. A system that employs a different scheme will either have to 
be prepared to map between its own scheme and IMPP (this may be 
nontrivial) and/or support a different form of display for IMPP 
presentities/tuples. I think that Mark is simply asking that people design 
now for the latter.

Nick




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