Subject: RE: [Sipping] I-D ACTION:draft-fujimoto-sipping-header-lang-00.tx t

From: Adam Roach <[email-masked]>
Date: Thu, 12 Sep 2002 10:57:46 -0500

This is a really good start. The requirements section seems to be
spot-on what we need.

It's a bit odd to have the requirements and the solution specified
in the same document; you might want to split them out into separate
documents. I suspect you will be able to get consensus on the
requirements faster than the mechanism. Also, as a minor procedural
point, if this work is put on the charters, I think the requirements
will be specified in SIPPING, and the mechanism will be specified
in SIP.

Speaking to the mechanism, the current draft has the following
text, which acknowledges but rejects Unicode language tags:

    UTF-8 allows to represent any UCS-2/4 characters, including recent 
    proposed "language tag" which used to specifying the languages 
    information for following character strings. However, the deployed 
    SIP implementations may not have enough knowledge to handle them 
    correctly.  

Your assertion that most (if not all) deployed SIP implementations
don't support Unicode language tagging is almost certainly correct;
however, since *no* existing SIP implementations support the mechanism
proposed in your draft, it seems to be a wash. In other words,
this argument provides no motivation for discarding Unicode language
tagging.

I invite members of the SIP community to chime in with their opinion
on this topic. As I see it, the primary differences involved are:

- Selecting Unicode language tags would be more standard, inasmuch
  as the representation of languages in this fashion is likely
  to see far wider deployment than any SIP-specific solution. So,
  for example, if the receiving UA uses Unicode libraries that
  inherently understand language tags, it makes implementation much
  simpler.

- Shingo Fujimoto's proposal is more space efficient. For example,
  to encode a set of ISO639/ISO3166 (language, country) codes into
  a header takes only 9 additional octets, instead of the 24 that
  UTF-8 encoding of language tags would; encoding just the language
  takes 6 additional octets instead of 12.

/a

> -----Original Message-----
> From: Shingo Fujimoto [mailto:[email-masked]]
> Sent: Wednesday, September 11, 2002 22:17
> To: sipping-WG
> Subject: Re: [Sipping] I-D 
> ACTION:draft-fujimoto-sipping-header-lang-00.txt
> 
> 
> Hi, all.
> 
> This I-D is about the issue which discussed on SIP-ML originally.
> 
> You can see the previous discussion from SIP-ML archives:
> 
> http://www1.ietf.org/mail-archive/working-groups/sip/current/m
> sg06075.html
> 
> I would appreciate your comments on my I-D.
> 
> Best.
> 
> [email-masked] wrote:
> > A New Internet-Draft is available from the on-line 
> Internet-Drafts directories.
> > 
> > 
> > 	Title		: SIP Header Language Information Extension
> > 	Author(s)	: S. Fujimoto
> > 	Filename	: draft-fujimoto-sipping-header-lang-00.txt
> > 	Pages		: 6
> > 	Date		: 2002-9-10
> > 	
> > This draft explains the problem when we use the UTF-8 character set 
> > to represent the language text other than English. This draft also 
> > describes the requirements to solve the problems, and proposes the 
> > extended syntax to SIP protocol message syntax specification.
> > 
> > A URL for this Internet-Draft is:
> > 
http://www.ietf.org/internet-drafts/draft-fujimoto-sipping-header-lang-00.tx
t

-- 
======================================
         SHINGO FUJIMOTO
    FUJITSU LABORATORIES LIMITED
E-mail: [email-masked]

_______________________________________________
Sipping mailing list  https://www1.ietf.org/mailman/listinfo/sipping
This list is for NEW development of the application of SIP
Use [email-masked] for questions on current sip
Use [email-masked] for new developments of core SIP
_______________________________________________
Sipping mailing list  https://www1.ietf.org/mailman/listinfo/sipping
This list is for NEW development of the application of SIP
Use [email-masked] for questions on current sip
Use [email-masked] for new developments of core SIP

---

From: Shingo Fujimoto <[email-masked]>
Date: Tue, 17 Sep 2002 17:37:49 +0900

Thank you for your comments.

My comments are inline.

> will be specified in SIPPING, and the mechanism will be specified

Your are right. When the I-D is updated they will be two documents 
(requirements, and proposal).

Since I am kind of new comer in SIP community, I am not sure which 
WG should handle these problem.

> this argument provides no motivation for discarding Unicode language

I think major differece between "language tag" and my proposal is 
ease of ignorance. The inline language tag is hard to separate the 
language tagging and other parts.

I cannot provide enough evidence about this statement, but here is 
the 3rd party article which described why "language tag" is 
discourged in most cases.

http://xml.coverpages.org/languageIdentifiers.html#unicode

>   takes 6 additional octets instead of 12.

I hope SIP-WG will also pay attension to my proposal.

The URL for my I-D is:
http://www.ietf.org/internet-drafts/draft-fujimoto-sipping-header-lang-00.txt

Best.