Re: [idn] Debunking the ACE myth

["Eric A. Hall" <ehall@ehsco.com>]

> delivering to a file is a protocol.  not all protocols involve
> direct interaction between the producer and the consumer.

If there is no direct interaction, there has to be an out-of-band
negotiation. However you do this is entirely up to you. Until you come up
with a mechanism that works reliably however, I would suggest that SMTP
should not be upgraded.

The dual-mode model helps you deliver on whatever you decide you can|wan't
to do. It won't break anything on it's own.

The example you cited is a broken SMTP implementation, and has absolutely
nothing to do with the DNS model.

> Version tags don't help if the browser doesn't understand the version.
> (we realized that MIME-Version was essentially useless only after
> RFC 1341 made it mandatory.  by the time we realized this, it was
> too late to deprecate it - too many UAs refused to recognize MIME
> without it.)

Thanks for proving my point; the only time that there will be bleed-over
is when the applications fail. You can use your MIME experience to prevent
this from happening again.

The dual-mode protocol won't break anything. Applications that implement
it poorly will.

> > > on-the-fly format conversion adds it own set of problems.
> >
> > Such as?
> 
> It introduces errors that are difficult to trace and to fix.

ACE even moreso.

> It adds complexity (for example into MTAs) that shouldn't be
> modifying their payloads. It forces intermediaries to be aware
> of their payloads' formats when those formats should be transparent.

If you want to insist that MTAs should track message formats on a
per-destination basis, that is your call.

-- 
Eric A. Hall                                        http://www.ehsco.com/
Internet Core Protocols          http://www.oreilly.com/catalog/coreprot/