Subject: [Slim] Discussion of "lang" attribute in MMUSIC WG

From: Bernard Aboba <[email-masked]>
Date: Fri, 22 Jul 2016 13:35:35 +0200

We had a short discussion of the history of the "lang" attribute within the
MMUSIC WG meeting today (July 22).

Colin Perkins pointed out that the text for the "lang" attribute originated
in RFC 2327 which was published in April 1998, and did not change much if
at all in RFC 4566 (published in July 2006). Therefore it would appear that
the RFC 4566bis revision to that text is the first time that this language
has been modified in 19 years.  This may be indicative of minimal
implementer interest.
When asked whether anyone at the MMUSIC WG had implemented the "lang"
attribute, there was no response.

Since the "lang" attribute text in question predates SIP (RFC 2543), as
well as Offer/Answer (RFC 3264), it was likely to have been originally
intended for use in multicast conferencing (which was mainstream at the
time) rather than in SIP-based Offer/Answer, which came later.

---

From: Randall Gellens <[email-masked]>
Date: Fri, 22 Jul 2016 13:13:50 -0700

Hi Bernard,

At 1:35 PM +0200 7/22/16, Bernard Aboba wrote:

>  We had a short discussion of the history of the "lang" attribute 
> within the MMUSIC WG meeting today (July 22).

Thanks very much for following up.

>  Colin Perkins pointed out that the text for the "lang" attribute 
> originated in RFC 2327 which was published in April 1998, and did 
> not change much if at all in RFC 4566 (published in July 2006). 
> Therefore it would appear that the RFC 4566bis revision to that 
> text is the first time that this language has been modified in 19 
> years.  This may be indicative of minimal implementer interest.
>  When asked whether anyone at the MMUSIC WG had implemented the 
> "lang" attribute, there was no response.

When I started the human language in real time communications draft, 
I searched all RFCs and I-Ds for any reference to 'lang' and could 
only find one, in an expired draft.  So, it does appear to not be 
used.  Which is good because there's less risk of confusion or 
conflict with our new attributes.

>  Since the "lang" attribute text in question predates SIP (RFC 
> 2543), as well as Offer/Answer (RFC 3264), it was likely to have 
> been originally intended for use in multicast conferencing (which 
> was mainstream at the time) rather than in SIP-based Offer/Answer, 
> which came later.

That makes a lot of sense, and fits with how I interpreted the 
wording defining the attribute (that multiple values meant multiple 
languages were used in the media).

--Randy

-- 
Randall Gellens
Opinions are personal;    facts are suspect;    I speak for myself only
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