Re: [sip] extensions of "handling" parameter of Content-Disposition header

Hello,

see further explanation below.

for some reason the initial mail was sent again, sorry about that.

Kind regards

Ivo Sedlacek
Siemens
PSE CZ TMM MMA8
phone: +420 5 3877 6532
email: [email protected], [email protected]

Mailcode: tL3PbjBL

-----Original Message-----
From: ext Paul Kyzivat [mailto:[email protected]] 
Sent: 23. září 2008 6:46
To: Sedlacek Ivo
Cc: 'ext Eric Burger'; 'SIP IETF'
Subject: Re: [Sip] [sip] extensions of "handling" parameter of
Content-Disposition header

Sedlacek Ivo wrote:
> > Hello Eric,
> >
> > thanks for your mail.
> >
> >>  What precisely is the use case behind your request?
> >
> > The use case is to initiate sharing of a resource (stored at an external
> > server) to participants of a tightly coupled conference (RFC4353).
> 
> Can you give a concrete example of what this means?
> I'm still totally in the dark about what you are trying to do.

There is a SIP based multiparty conference with a focus - every participant
is connected using a SIP dialog to a central focus, which mixes/switches
Media sent by the participants.
One of the participants wants the focus to fetch e.g. a picture / an audio
clip from an HTTP server / an RTSP server and play it to the conference
participants using their media streams negotiated in SIP dialogs.
Hope this makes this use case clearer.

> > After the tightly coupled conference is established, a participating
> > client sends a SIP request containing a MIME body of MIME type
> > message/external-body (RFC2017) towards the focus. The "URL"
> > parameter of the Content-Type header of the MIME body contains URL of
> > the resource to be shared. The "handling" parameter with value "xyz" of
> > the Content-Disposition header of the MIME body indicates to the focus
> > that this is not a regular message/external-body but it is a request to
> > initiate sharing of the resource to participants.
> >
> > When the focus receives a SIP request with the MIME body of MIME type
> > message/external-body with the "handling" parameter of Content-Dispotion
> > header set to "xyz", the focus will start sharing the resource indicated
> > by the URL of the MIME body of MIME type message/external-body.
> 
> I have no clue what it means for the focus to share the resource.

As mentioned above - by "sharing the resource"  I meant the focus is
fetching the picture / audio clip from the HTTP server / the RTSP server and
distribute it using the MSRP / MSRP media streams agreed in the SIP sessions
to the participants.

> 
> I'm going to reserve judgment about this topic until I have an idea what
> you are trying to do.
> 
> 	Thanks,
> 	Paul
> 
> > If the focus received the SIP request with the MIME body of MIME type
> > message/external-body WITHOUT the "handling" parameter of
> > Content-Dispotion header set to "xyz", the focus would behave
> > differently - e.g. initiate the SIP requests towards the other
> > participants and include there the MIME body.
> >
> > Other considered method is to initiate sharing of the resource
> > using 5.2. Adding Participants of RFC4353 - the participating client
> > indicates to the focus to add the resource as added participant. The
> > focus applies a special policy when the focus detects the referred URI
> > is not a user.
> >
> > Kind regards
> >
> > *Ivo Sedlacek*
> > Siemens
> > PSE CZ TMM MMA8
> > phone: +420 5 3877 6532 <tel:+420543106532>
> > email: [email protected] <mailto:[email protected]>,
> > [email protected] <mailto:[email protected]>
> >
> > Mailcode: tL3PbjBL
> >
> >
> > ------------------------------------------------------------------------
> > *From:* ext Eric Burger [mailto:[email protected]]
> > *Sent:* 19. září 2008 22:04
> > *To:* Sedlacek Ivo
> > *Cc:* SIP IETF
> > *Subject:* Re: [Sip] [sip] extensions of "handling" parameter of
> > Content-Disposition header
> >
> > Absolutely.  Here is the deal:
> >
> > ;handling is a parameter that tells the UAS that is MUST (or MAY)
> > understand the body part in its processing of the SIP message.
> > "Understand" usually means "can process" the body part, but that is an
> > implementation issue.
> >
> > Content-Disposition is a parameter that tells the UAS what to do with
> > the body part.
> >
> > Now, looking at your question, Content-Disposition is probably not what
> > you want, either. You say, "to signal a particular action which the
> > sender requests from the recipient". That implies signaling.
> > Content-Disposition is not signaling. Content-Disposition is a hint to
> > the UAS as to what it should do with the body. If you want to signal an
> > action at the UAS, then you more likely want one of (new) INFO packages,
> > PUBLISH/SUBSCRIBE, or a new SIP header.
> >
> > What precisely is the use case behind your request?
> >
> >
> > On Sep 19, 2008, at 7:16 AM, Sedlacek Ivo wrote:
> >
> >> Just to be absolutely sure - do you mean that it is more appropriate
> >> to create a new disposition-type of the Content-Disposition header
> >> (rather than creating new "handling" parameter values)? Thanks.
> >>
> >> Kind regards
> >>
> >> Ivo Sedlacek
> >> Siemens
> >> PSE CZ TMM MMA8
> >> phone: +420 5 3877 6532
> >> email: [email protected] <mailto:[email protected]>,
> >> [email protected] <mailto:[email protected]>
> >>
> >> Mailcode: tL3PbjBL
> >>
> >> -----Original Message-----
> >> From: ext Paul Kyzivat [mailto:[email protected]]
> >> Sent: 19. září 2008 14:08
> >> To: Sedlacek Ivo
> >> Cc: [email protected] <mailto:[email protected]>
> >> Subject: Re: [Sip] [sip] extensions of "handling" parameter of
> >> Content-Disposition header
> >>
> >> I can't think why you would want to have added values for the handling
> >> parameter. IMO what you want to do would be better served by values of
> >> the Content-Disposition itself.
> >>
> >>         Thanks,
> >>         Paul
> >>
> >> Sedlacek Ivo wrote:
> >> > Hello,
> >> >
> >> > can anyone please give me an expert opinion on possible extensions of
> >> > "handling" parameter defined in RFC3204/RFC3459?
> >> >
> >> > Is it appropriate to extend and use the "handling" parameter of
> >> > Content-Disposition header of a MIME body inserted in a SIP request
to
> >> > signal a particular action which the sender requests from the
recipient?
> >> >
> >> > For example - if the "handling" parameter contained value "XYZ", the
SIP
> >> > request recipient would do a special action ActionXYZ using the MIME
> >> > body. If the MIME body was included in the SIP request without the
> >> > "handling" parameter, the recipient would NOT do the special action
XYZ
> >> > and instead would just store or render the MIME body.
> >> >
> >> > AFAIK, RFC3204 defines parameter "handling" of Content-Disposition
> >> > header of a MIME body with two defined parameter values "required"
and
> >> > "optional" and allows for possible future extensions. RFC3204 also
> >> > states "The handling parameter, handling-parm, describes how the UAS
> >> > should react if it receives a message body whose content type or
> >> > disposition type it does not understand". RFC3459 says "The protocol
> >> > described here is identical in functionality to RFC 3204 with respect
to
> >> > SIP.".
> >> >
> >> > Kind regards
> >> >
> >> > *Ivo Sedlacek*
> >> > Siemens
> >> > PSE CZ TMM MMA8
> >> > phone: +420 5 3877 6532 <tel:+420543106532>
> >> > email: [email protected] <mailto:[email protected]>
> >> <mailto:[email protected]>,
> >> > [email protected] <mailto:[email protected]>
> >> <mailto:[email protected]>
> >> >
> >> > Mailcode: tL3PbjBL
> >> >
> >> >
> >> >
> >> >
------------------------------------------------------------------------
> >> >
> >> > _______________________________________________
> >> > Sip mailing list  https://www.ietf.org/mailman/listinfo/sip
> >> > This list is for NEW development of the core SIP Protocol
> >> > Use [email protected]
> >> <mailto:[email protected]> for questions on current sip
> >> > Use [email protected] <mailto:[email protected]> for new developments
> >> on the application of sip
> >> _______________________________________________
> >> Sip mailing list  https://www.ietf.org/mailman/listinfo/sip
> >> This list is for NEW development of the core SIP Protocol
> >> Use [email protected]
> >> <mailto:[email protected]> for questions on current sip
> >> Use [email protected] <mailto:[email protected]> for new developments on
> >> the application of sip
> >
> >
> > ------------------------------------------------------------------------
> >
> > _______________________________________________
> > Sip mailing list  https://www.ietf.org/mailman/listinfo/sip
> > This list is for NEW development of the core SIP Protocol
> > Use [email protected] for questions on current sip
> > Use [email protected] for new developments on the application of sip
> 

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