Subject: Re: [idn] Reality Check

From: John C Klensin <[email-masked]>
Date: Mon, 16 Jul 2001 05:28:43 -0400

--On Sunday, 15 July, 2001 22:35 -0500 "Eric A. Hall"
<[email-masked]> wrote:

> As an aside, it is possible to upgrade many of the legacy
> protocols to UTF-8 without actually changing the protocol
> semantics, simply by using out-of-band negotation features.
> Finger, Echo, Gopher, etc., all of them could be upgraded. Not
> by this WG of course, but the work that this WG performs will
> dictate how that work eventually happens.
> 
> For example, if there's an out-of-band negotiation for "use
> UTF-8" that is glued onto finger, then the output can be
> internationalized, but the query inputs will also need to be
> internationalized for maximum functionality. This will include
> IDNs (with Finger in particular).

Eric,

Could you elaborate on what you propose to do with "out of band
negotiation" in these cases.  I can certainly understand a
protocol in which you call me, ask if my server is upgraded, and
then put it on a list, but such things traditionally have lousy
scaling and long-term properties.  It is difficult for me to
imagine how you would add anything out of band to finger, whois,
or other "one connection, one exchange" protoocols.  What did you
have in mind?

    john

---

From: "Eric A. Hall" <[email-masked]>
Date: Mon, 16 Jul 2001 09:03:59 -0500

> It is difficult for me to imagine how you would add anything out of
> band to finger, whois, or other "one connection, one exchange"
> protoocols.  What did you have in mind?

Using transport-layer options to negotiate over compression, encryption,
charset and other per-session characteristics.

With finger, for example, the client and server could use TCP options to
negotiate over the charset, without having to change the finger protocol
semantics whatsoever.

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

---

From: John C Klensin <[email-masked]>
Date: Mon, 16 Jul 2001 13:35:17 -0400

--On Monday, 16 July, 2001 09:03 -0500 "Eric A. Hall"
<[email-masked]> wrote:

> 
>> It is difficult for me to imagine how you would add anything
>> out of band to finger, whois, or other "one connection, one
>> exchange" protoocols.  What did you have in mind?
> 
> Using transport-layer options to negotiate over compression,
> encryption, charset and other per-session characteristics.
>...

Ok, that is fair, although I personally believe that moving
applications options (such as most of the above) down to the
transport layer would introduce layering problems that we would
come to very seriously regret in the future.
  
> With finger, for example, the client and server could use TCP
> options to negotiate over the charset, without having to change
> the finger protocol semantics whatsoever.

Yep.  Although I think that institutionalizing that type of layer
violation would be much more likely to wreck the Internet than
anything we could do with the DNS.  Remember that the corollary
to the end to end principle that we don't change the transport
core to accomodate particular applications is considered by many
to be the key doctrine that has preserved our ability to quickly
innovate and test new ideas.

Just my impression, however.

     john