Re: Length of labels (RE: [idn] IURL vs URL, IDNS name vs DNS name)

[tinwee@pobox.org.sg]

Yes, but don't we have to  handle the transition period where some
have changed and others haven't? and so shouldn't we try to opt
for solutions where those who want to upgrade or have upgraded
can do so, and those who lag behind won't get royally screwed up?
Can we please opt for solutions where the change is minimal to the
existing DNS infrastructure?

Tin Wee

"Donald E. Eastlake 3rd" wrote:
> 
> In other words, it would be just about as easy, and much safer, to
> define a new UTF8 or whatever label type for DNS as it would be to
> fundamentally change the "ASCII" label type to have a different length
> limit.  (Yes, I'm quite aware that arbitrary binary values can be put
> in "ASCII" DNS labels but applications screw up royally on nulls and
> the like and the case folding can screw you pretty badly.)
> 
> If you are willing to contemplate software mods to everything that has
> to touch idn's, a new label type to add to the existing "ASCII" and
> recently defined bit string "binary" labels is probably the cleanest
> thing.
> 
> Donald
> 
> From:  Harald Tveit Alvestrand <Harald@Alvestrand.no>
> Message-Id:  <4.2.0.58.20000214235943.0275d510@dokka.maxware.no>
> Date:  Tue, 15 Feb 2000 00:05:55 +0100
> To:  Jonathan Rosenne <rosenne@qsm.co.il>, idn@ops.ietf.org
> In-Reply-To:  <NDBBIFGHGLJILJGHOEELKEIKCEAA.rosenne@qsm.co.il>
> References:  <1046892284.950234664@p2.jck.com>
> 
> >At 19:00 11.02.00 +0200, Jonathan Rosenne wrote:
> >
> >>The UCS could be encoded using A-Z 0-9. On average each non-ASCII character
> >>would require 3 to 4 characters. All we need to change is to allow longer
> >>names in DNS and to provide a viewer which decodes these creatures back to
> >>UCS or the local code page.
> >
> >Unfortunately the limit of 63 octets per domain name component is enshrined
> >in a 6-bit length field in RFC 1035, section 4.1.4 (the 2 upper bits are
> >used as a flag to indicate pointers or "something-elses"), so "all we need
> >to change" to get this length increased is every single piece of DNS
> >software on the planet.
> >
> >Not that we might not come to that anyway...
> >
> >                          Harald
> >
> >--
> >Harald Tveit Alvestrand, EDB Maxware, Norway
> >Harald.Alvestrand@edb.maxware.no