RE: [Sip] Support for Multipart/MIME

["Dan Wing" <[e-mail]>]

The now-expired draft
http://tools.ietf.org/html/draft-jennings-sipping-multipart-02 explored
multipart/alternative.  One difficulty, however, is what does it mean to say
"can understand a part".

This is easy if one part is SDP and another part is SDPng.  If you
understand SDPng, you process it; if you don't, you process the SDP.

However, it's really hard if one part is SDP and another part is also SDP --
in some cases we would like the answerer to "pick the better SDP".  At the
time, we were considering multipart/alternative as a way to offer RTP
(RTP/AVP) and SRTP (RTP/SAVP), but we found it doesn't work well at all.
Since then, draft-ietf-mmusic-sdp-capability-negotiation is a superior
solution to sending an offer containing RTP and SRTP.  

I suppose we could avoid the difficulty by prohibiting identical
Content-Types in the alternatives.

-d


> -----Original Message-----
> From: Christer Holmberg (JO/LMF) 
> [mailto:[e-mail]] 
> Sent: Thursday, May 03, 2007 3:50 AM
> To: [e-mail]; [e-mail]
> Subject: RE: [Sip] Support for Multipart/MIME
> 
> 
> Hi,
> 
> Multipart/alternative is interesting. I guess that, for SDP, 
> it could be
> used to provide different "offer alternatives". I think it 
> would be good
> to compare it against some of the other grouping/alternative 
> mechanisms
> we have defined for that purpose.
> 
> Regards,
> 
> Christer
>  
> 
> > -----Original Message-----
> > From: [e-mail] [mailto:[e-mail]] 
> > Sent: 30. huhtikuuta 2007 19:13
> > To: [e-mail]
> > Subject: Re: [Sip] Support for Multipart/MIME
> > 
> >    From: Cullen Jennings <[e-mail]>
> > 
> >    I think the WG should consider an update to 3261 (likely 
> > done through  
> >    the process Keith has proposed) that makes this multipart/MIME  
> >    mandatory to implement.
> > 
> > I assume that the requirement is that if a message has a 
> > multipart/alternative body, and the UA is capable of 
> > understanding one part of the body, then it must be able to 
> > extract that part and use it to process the message.
> > 
> > Dale
> > 
> > 
> > _______________________________________________
> > 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
> > 
> 
> 
> _______________________________________________
> 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


_______________________________________________
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