Re: length restrictions on IDN label
"Adam M. Costello" <[email protected]>
| Newsgroups | gmane.ietf.idn |
|---|---|
| Message-ID | <[email protected]> |
Soobok Lee <[email protected]> wrote: > If UTF8-encoded, that valid 8bit label will exceed 63 octets limits > (up to 168 octets or more) True. > which is imposed by RFC1035 even upon non-ASCII 8bit labels . Yes, but labels in DNS containing octets >= 128 are not internationalized labels, because internationalized labels use only octets <= 127 in DNS. Labels in DNS containing octets >= 128 are mysterious creatures that have no standard interpretation as text (because ASCII is the only text encoding used by the DNS standard). > IDNA section 6.3 does not rule out that utf8 encoded labels may be > used in DNS wire protocols in the future. In which case the specification of those future wire protocols will need to deal with the fact that UTF-8 forms of internationalized labels can have more than 63 octets. (255 is an upper bound, though not the least upper bound.) AMC