Re: [MMUSIC] WGLC of draft-ietf-mmusic-rfc2326bis-29.txt

[Magnus Westerlund <[e-mail]>]

Hi,

I have to add a WG last call comment on my own document. This comes from
a discussion on the AVTCORE ECN for RTP document with Pete Resnick
regarding ABNF extension definitions and the qdtext definition of UTF-8.

Fist of all it doesn't provide any escaping of strings including " and
secondly its definition of UTF-8 and additional characters are in error.


>     quoted-string   =  ( DQ *qdtext DQ )
>     qdtext          =  %x20-21 / %x23-7E / %x80-FF / UTF8-NONASCII
>                        ; any UTF-8 TEXT except<">
>     DQ              =  %x22  ; US-ASCII double-quote mark (34)
>     UTF8-NONASCII    =  %xC0-DF 1UTF8-CONT
>                      /  %xE0-EF 2UTF8-CONT
>                      /  %xF0-F7 3UTF8-CONT
>                      /  %xF8-FB 4UTF8-CONT
>                      /  %xFC-FD 5UTF8-CONT
>     UTF8-CONT        =  %x80-BF
>
First of all, I don't think you should be including %x80-FF not in the
context of UTF-8. As you said, if you want binary content (or random
octets), you can always BASE64 the thing. This should be for strings,
and that means either US-ASCII or UTF-8 and nothing else.

I think you should incorporate definitions from 5234 (DQUOTE) and 3629
(UTF8-1, UTF8-2, UTF8-3, and UTF8-4) and simply make this:

quoted-string = ( DQUOTE *qdtext DQUOTE )
qdtext = %x20-21 / %x23-7E / UTF8-NONASCII
UTF8-NONASCII = UTF8-1 / UTF8-2 / UTF8-3 / UTF8-4

If you want to add the quoted-pair escaping mechanism, the simplest
would be:

quoted-string = ( DQUOTE *qdtext DQUOTE )
qdtext = %x20-21 / %x23-5B / %x5D-7E / quoted-pair / UTF8-NONASCII
    ; No DQUOTE and no "\"
quoted-pair = "\\" / ( "\" DQUOTE )
UTF8-NONASCII = UTF8-1 / UTF8-2 / UTF8-3 / UTF8-4

Cheers

Magnus Westerlund

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