Re: [Sip] Support for Multipart/MIME

[Paul Kyzivat <[e-mail]>]

Dan,

If I follow what you are saying then I disagree with the use case.

I believe the Content-Language specifies the language of the text in the 
body part, not the language that might be conveyed in a media stream 
that is negotiated by the SDP in the body part.

	Paul

Dan Wing wrote:
> 
>> -----Original Message-----
>> From: Gonzalo Camarillo [mailto:[e-mail]] 
>> Sent: Wednesday, May 30, 2007 1:57 AM
>> To: Dan Wing
>> Cc: 'Paul Kyzivat'; 'Francois Audet'; [e-mail]; 'Christer 
>> Holmberg (JO/LMF)'
>> Subject: Re: [Sip] Support for Multipart/MIME
>>
>> Hi Dan,
>>
>> thanks for the pointers. It seems that we want to specify that, for 
>> multipart/alternative bodies whose content disposition is 
>> "session" (or 
>> early session), the content-types of all body parts MUST be different.
>>
>> However, multipart/alternative bodies with a different 
>> disposition type should follow the general MIME rules.
> 
> Yes, I concur.
> 
> You also brought up an interesting point with language.  One Might Consider
> it reasonable to have multipart/alternative, with several application/sdp
> parts which differ in language (and probably different m/c lines).  Your
> document should probably provide a pointer to SDP's a=lang and guidance
> towards its use in conjunction with SDP Capability Negotiation.  Sortof a
> 'you might be tempted to use MIME constructs where SDP should be used
> instead'.  That is, if there is agreement that a=lang and SDP Capability
> Negotiation is the right way to select language.
> 
> (I'm thinking of situations where, for example, you want to send an offer
> for an English, German, or French announcement ("The dam broke, please
> evacuate to higher ground") or an IVR or a human telephone operator).
> 
> -d
> 
>> Cheers,
>>
>> Gonzalo
>>
>>
>> Dan Wing wrote:
>>> Paul Kyzivat wrote: 
>>> ...
>>>>>    OPEN ISSUE 2: we know that we do not want two SDPs in a 
>>>>> 'multipart/
>>>>>    alternative', but is this valid generally with any 
>> content type?
>>>>>    Would it be possible to provide two alternative body 
>>>>> parts using the
>>>>>    same format and, thus, the same content type but in, 
>>>>> say, different
>>>>>    languages?
>>>> Its my understanding that the distinction is based on which can be 
>>>> understood, relative to Content-Type. It isn't apparent to me that 
>>>> making this decision based on other attributes is valid. For 
>>>> one thing the parts are supposed to be ordered by increasing 
>>>> richness.  If they differed by language this wouldn't be true.
>>> Multipart/alternative is the best we have, though.  And who 
>> is to say that
>>> image/jpeg is richer than image/gif, or that english is 
>> richer than latin?  
>>> Anyway, the following RFCs standardize the use of 
>> Content-Language and refer
>>> to using multipart/alternative when providing support for multiple
>>> languages:
>>>
>>>   http://tools.ietf.org/html/rfc3282
>>>   http://tools.ietf.org/html/rfc3066
>>>
>>> -d
>>>
> 


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