Re: Simple Digest, Vol 102, Issue 4
venu Y <[email protected]> Fri, 12 Oct 2012 10:34:04 +0530
| Newsgroups | gmane.ietf.simple |
|---|---|
| Message-ID | <CAN+uxjKmOB7LZeGzkHPUFZnzt0MY5yOSC3C5L1mkoSQqUU_t6w@mail.gmail.com> |
Hi, For file transfer we can uniquely identify the session, based on 'a=file-selector' attribute. But for IM/MMS/Screen sharing... it's very unpredictable. Will it solve all the problem if instead of m=message, if we have m=im m=screen-share m=ftp etc., or Using 'SIP Tags' in the OFFER will solve most of the issues.. but will the order of the Tags and 'm=' line are in sync or not is the issue? Thanks and Regards -Venu On Fri, Oct 12, 2012 at 12:30 AM, <[email protected]> wrote: > If you have received this digest without all the individual message > attachments you will need to update your digest options in your list > subscription. To do so, go to > > https://www.ietf.org/mailman/listinfo/simple > > Click the 'Unsubscribe or edit options' button, log in, and set "Get > MIME or Plain Text Digests?" to MIME. You can set this option > globally for all the list digests you receive at this point. > > > > Send Simple mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > https://www.ietf.org/mailman/listinfo/simple > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Simple digest..." > > > Today's Topics: > > 1. Re: How to identify application type of MSRP session. > (Adrian Georgescu) > 2. Re: How to identify application type of MSRP session. > (Paul Kyzivat) > 3. Re: How to identify application type of MSRP session. > (Adrian Georgescu) > 4. Re: How to identify application type of MSRP session. > (Paul Kyzivat) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 10 Oct 2012 22:53:53 +0200 > From: Adrian Georgescu <[email protected]> > To: Paul Kyzivat <[email protected]> > Cc: [email protected] > Subject: Re: [Simple] How to identify application type of MSRP > session. > Message-ID: <[email protected]> > Content-Type: text/plain; charset=us-ascii > > > On Oct 9, 2012, at 5:24 PM, Paul Kyzivat wrote: > > > On 10/9/12 1:16 AM, Prasun Bheri wrote: > >> Thanks Paul and Adrian. > >> Does it not create inter-op issues? > >> What is the best approach to inter-opp with other msrp implementations. > > > > Certainly it could. > > > > Can you please provide a real life example about how this can happen? > > > > The issue arises when you try to multiplex multiple "applications" on a > single AOR and, I gather, a single dialog. Standardizing such usage would > seem to require a new higher level application framework on top of sip. One > such framework that comes to mind is IMS. > > I am using such single dialog scenario with MSRP and I am not able to find > any issue with it. Can you please expand what issue you are referring to. > > Adrian > > > > > Thanks, > > Paul > > > >> Thanks & Regards > >> Prasun > >> > >> On Mon, Oct 8, 2012 at 8:14 PM, Paul Kyzivat <[email protected] > >> <mailto:[email protected]>> wrote: > >> > >> On 10/8/12 3:11 AM, Prasun Bheri wrote: > >> > >> Hello Group, > >> I would like to use MSRP for various applications such as IM/File > >> Transfer/Screen sharing etc. > >> > >> What is the right way to identify, which MSRP session belongs to > >> which > >> application? > >> > >> Looking at SDP in SIP INVITE all applications could have same > >> accept-types. > >> > >> > >> AFAIK there are no specific standards for this, but there are > >> mechanisms you can use. > >> > >> E.g. you may use the a=label attribute in sdp to associate an m-line > >> with a label that is significant to an application. > >> > >> Thanks, > >> Paul > >> > >> > >> _________________________________________________ > >> Simple mailing list > >> [email protected] <mailto:[email protected]> > >> https://www.ietf.org/mailman/__listinfo/simple > >> <https://www.ietf.org/mailman/listinfo/simple> > >> > >> > > > > _______________________________________________ > > Simple mailing list > > [email protected] > > https://www.ietf.org/mailman/listinfo/simple > > > > > > ------------------------------ > > Message: 2 > Date: Wed, 10 Oct 2012 17:22:13 -0400 > From: Paul Kyzivat <[email protected]> > To: Adrian Georgescu <[email protected]> > Cc: [email protected] > Subject: Re: [Simple] How to identify application type of MSRP > session. > Message-ID: <[email protected]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > On 10/10/12 4:53 PM, Adrian Georgescu wrote: > > > > On Oct 9, 2012, at 5:24 PM, Paul Kyzivat wrote: > > > >> On 10/9/12 1:16 AM, Prasun Bheri wrote: > >>> Thanks Paul and Adrian. > >>> Does it not create inter-op issues? > >>> What is the best approach to inter-opp with other msrp implementations. > >> > >> Certainly it could. > >> > > > > Can you please provide a real life example about how this can happen? > > > > > >> The issue arises when you try to multiplex multiple "applications" on a > single AOR and, I gather, a single dialog. Standardizing such usage would > seem to require a new higher level application framework on top of sip. One > such framework that comes to mind is IMS. > > > > I am using such single dialog scenario with MSRP and I am not able to > find any issue with it. Can you please expand what issue you are referring > to. > > Presumably you are encoding some "application identifier" somewhere, to > distinguish between file transfer, screen sharing, etc. (E.g. you could > be using a=label for this.) > > This will work fine as long as you have control over the top level "meta > application" at each end, and thus can assure that both ends agree on > how to interpret which application is intended. > > But it will stop working as soon as you bring in some different > application at one end that doesn't understand your application > identifiers. > > So as long as you only want a proprietary solution there is no problem. > When you want to open it up you can either convince everybody else to > follow your defacto proprietary "standard", or you can come back here > and create a real standard. > > Thanks, > Paul > > > Adrian > > > >> > >> Thanks, > >> Paul > >> > >>> Thanks & Regards > >>> Prasun > >>> > >>> On Mon, Oct 8, 2012 at 8:14 PM, Paul Kyzivat <[email protected] > >>> <mailto:[email protected]>> wrote: > >>> > >>> On 10/8/12 3:11 AM, Prasun Bheri wrote: > >>> > >>> Hello Group, > >>> I would like to use MSRP for various applications such as > IM/File > >>> Transfer/Screen sharing etc. > >>> > >>> What is the right way to identify, which MSRP session belongs > to > >>> which > >>> application? > >>> > >>> Looking at SDP in SIP INVITE all applications could have same > >>> accept-types. > >>> > >>> > >>> AFAIK there are no specific standards for this, but there are > >>> mechanisms you can use. > >>> > >>> E.g. you may use the a=label attribute in sdp to associate an > m-line > >>> with a label that is significant to an application. > >>> > >>> Thanks, > >>> Paul > >>> > >>> > >>> _________________________________________________ > >>> Simple mailing list > >>> [email protected] <mailto:[email protected]> > >>> https://www.ietf.org/mailman/__listinfo/simple > >>> <https://www.ietf.org/mailman/listinfo/simple> > >>> > >>> > >> > >> _______________________________________________ > >> Simple mailing list > >> [email protected] > >> https://www.ietf.org/mailman/listinfo/simple > >> > > > > > > > > ------------------------------ > > Message: 3 > Date: Wed, 10 Oct 2012 23:54:14 +0200 > From: Adrian Georgescu <[email protected]> > To: Paul Kyzivat <[email protected]> > Cc: [email protected] > Subject: Re: [Simple] How to identify application type of MSRP > session. > Message-ID: <[email protected]> > Content-Type: text/plain; charset=us-ascii > > Hi Paul, > > I can see what you mean now. My understanding is that when interpreting > the SDP one could do something like: > > 1. If one does not understand an m line, it will not use it and any a > lines related to it > 2. If one does understand an m line, will look necessarily at all a lines > to figure out more details it understands and discard the ones it does not > > Are these assumptions good to have interoperability with other SDP > end-points? > > Adrian > > On Oct 10, 2012, at 11:22 PM, Paul Kyzivat wrote: > > > On 10/10/12 4:53 PM, Adrian Georgescu wrote: > >> > >> On Oct 9, 2012, at 5:24 PM, Paul Kyzivat wrote: > >> > >>> On 10/9/12 1:16 AM, Prasun Bheri wrote: > >>>> Thanks Paul and Adrian. > >>>> Does it not create inter-op issues? > >>>> What is the best approach to inter-opp with other msrp > implementations. > >>> > >>> Certainly it could. > >>> > >> > >> Can you please provide a real life example about how this can happen? > >> > >> > >>> The issue arises when you try to multiplex multiple "applications" on > a single AOR and, I gather, a single dialog. Standardizing such usage would > seem to require a new higher level application framework on top of sip. One > such framework that comes to mind is IMS. > >> > >> I am using such single dialog scenario with MSRP and I am not able to > find any issue with it. Can you please expand what issue you are referring > to. > > > > Presumably you are encoding some "application identifier" somewhere, to > distinguish between file transfer, screen sharing, etc. (E.g. you could be > using a=label for this.) > > This will work fine as long as you have control over the top level "meta > application" at each end, and thus can assure that both ends agree on how > to interpret which application is intended. > > > > But it will stop working as soon as you bring in some different > application at one end that doesn't understand your application identifiers. > > > > So as long as you only want a proprietary solution there is no problem. > When you want to open it up you can either convince everybody else to > follow your defacto proprietary "standard", or you can come back here and > create a real standard. > > > > Thanks, > > Paul > > > >> Adrian > >> > >>> > >>> Thanks, > >>> Paul > >>> > >>>> Thanks & Regards > >>>> Prasun > >>>> > >>>> On Mon, Oct 8, 2012 at 8:14 PM, Paul Kyzivat <[email protected] > >>>> <mailto:[email protected]>> wrote: > >>>> > >>>> On 10/8/12 3:11 AM, Prasun Bheri wrote: > >>>> > >>>> Hello Group, > >>>> I would like to use MSRP for various applications such as > IM/File > >>>> Transfer/Screen sharing etc. > >>>> > >>>> What is the right way to identify, which MSRP session belongs > to > >>>> which > >>>> application? > >>>> > >>>> Looking at SDP in SIP INVITE all applications could have same > >>>> accept-types. > >>>> > >>>> > >>>> AFAIK there are no specific standards for this, but there are > >>>> mechanisms you can use. > >>>> > >>>> E.g. you may use the a=label attribute in sdp to associate an > m-line > >>>> with a label that is significant to an application. > >>>> > >>>> Thanks, > >>>> Paul > >>>> > >>>> > >>>> _________________________________________________ > >>>> Simple mailing list > >>>> [email protected] <mailto:[email protected]> > >>>> https://www.ietf.org/mailman/__listinfo/simple > >>>> <https://www.ietf.org/mailman/listinfo/simple> > >>>> > >>>> > >>> > >>> _______________________________________________ > >>> Simple mailing list > >>> [email protected] > >>> https://www.ietf.org/mailman/listinfo/simple > >>> > >> > >> > > > > _______________________________________________ > > Simple mailing list > > [email protected] > > https://www.ietf.org/mailman/listinfo/simple > > > > > > ------------------------------ > > Message: 4 > Date: Wed, 10 Oct 2012 18:48:27 -0400 > From: Paul Kyzivat <[email protected]> > To: Adrian Georgescu <[email protected]> > Cc: [email protected] > Subject: Re: [Simple] How to identify application type of MSRP > session. > Message-ID: <[email protected]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > On 10/10/12 5:54 PM, Adrian Georgescu wrote: > > Hi Paul, > > > > I can see what you mean now. My understanding is that when interpreting > the SDP one could do something like: > > > > 1. If one does not understand an m line, it will not use it and any a > lines related to it > > Yes, that is what you are expected to do. > You would want to reject the m-line in the answer with a zero port. > > > 2. If one does understand an m line, will look necessarily at all a > lines to figure out more details it understands and discard the ones it > does not > > Yes, this is also the expectation. > > > Are these assumptions good to have interoperability with other SDP > end-points? > > These are necessary but not sufficient for interoperability. > > If one side puts in a proprietary a-line that must be understood to > properly process the stream, and the other side doesn't understand that > line, ignores it, and then handles the stream in a different way, then > you still have an interoperability problem. > > For instance, suppose you support both IM and screen sharing via MSRP. > For one session you only intend to use screen sharing. You send off an > offer with the MSRP m-lline and your indication that this is for screen > sharing. The other side ignores that and assumes that this msrp session > is for IM. It may then bring up a UI, and do all sorts of odd things. > > You can probably avoid many problems just by which media types you > support on the msrp session. In fact, you might be able to solve most of > the problems you are trying to deal with by having unique media types > for each of your applications. If not, then be careful. > > If you aren't already aware of it, you should look at RFC 5547. > > Thanks, > Paul > > > Adrian > > > > On Oct 10, 2012, at 11:22 PM, Paul Kyzivat wrote: > > > >> On 10/10/12 4:53 PM, Adrian Georgescu wrote: > >>> > >>> On Oct 9, 2012, at 5:24 PM, Paul Kyzivat wrote: > >>> > >>>> On 10/9/12 1:16 AM, Prasun Bheri wrote: > >>>>> Thanks Paul and Adrian. > >>>>> Does it not create inter-op issues? > >>>>> What is the best approach to inter-opp with other msrp > implementations. > >>>> > >>>> Certainly it could. > >>>> > >>> > >>> Can you please provide a real life example about how this can happen? > >>> > >>> > >>>> The issue arises when you try to multiplex multiple "applications" on > a single AOR and, I gather, a single dialog. Standardizing such usage would > seem to require a new higher level application framework on top of sip. One > such framework that comes to mind is IMS. > >>> > >>> I am using such single dialog scenario with MSRP and I am not able to > find any issue with it. Can you please expand what issue you are referring > to. > >> > >> Presumably you are encoding some "application identifier" somewhere, to > distinguish between file transfer, screen sharing, etc. (E.g. you could be > using a=label for this.) > >> This will work fine as long as you have control over the top level > "meta application" at each end, and thus can assure that both ends agree on > how to interpret which application is intended. > >> > >> But it will stop working as soon as you bring in some different > application at one end that doesn't understand your application identifiers. > >> > >> So as long as you only want a proprietary solution there is no problem. > When you want to open it up you can either convince everybody else to > follow your defacto proprietary "standard", or you can come back here and > create a real standard. > >> > >> Thanks, > >> Paul > >> > >>> Adrian > >>> > >>>> > >>>> Thanks, > >>>> Paul > >>>> > >>>>> Thanks & Regards > >>>>> Prasun > >>>>> > >>>>> On Mon, Oct 8, 2012 at 8:14 PM, Paul Kyzivat <[email protected] > >>>>> <mailto:[email protected]>> wrote: > >>>>> > >>>>> On 10/8/12 3:11 AM, Prasun Bheri wrote: > >>>>> > >>>>> Hello Group, > >>>>> I would like to use MSRP for various applications such as > IM/File > >>>>> Transfer/Screen sharing etc. > >>>>> > >>>>> What is the right way to identify, which MSRP session > belongs to > >>>>> which > >>>>> application? > >>>>> > >>>>> Looking at SDP in SIP INVITE all applications could have same > >>>>> accept-types. > >>>>> > >>>>> > >>>>> AFAIK there are no specific standards for this, but there are > >>>>> mechanisms you can use. > >>>>> > >>>>> E.g. you may use the a=label attribute in sdp to associate an > m-line > >>>>> with a label that is significant to an application. > >>>>> > >>>>> Thanks, > >>>>> Paul > >>>>> > >>>>> > >>>>> _________________________________________________ > >>>>> Simple mailing list > >>>>> [email protected] <mailto:[email protected]> > >>>>> https://www.ietf.org/mailman/__listinfo/simple > >>>>> <https://www.ietf.org/mailman/listinfo/simple> > >>>>> > >>>>> > >>>> > >>>> _______________________________________________ > >>>> Simple mailing list > >>>> [email protected] > >>>> https://www.ietf.org/mailman/listinfo/simple > >>>> > >>> > >>> > >> > >> _______________________________________________ > >> Simple mailing list > >> [email protected] > >> https://www.ietf.org/mailman/listinfo/simple > >> > > > > > > > > ------------------------------ > > _______________________________________________ > Simple mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/simple > > > End of Simple Digest, Vol 102, Issue 4 > ************************************** > -- With Regards Venu 93484 89945 [email protected] _______________________________________________ Simple mailing list [email protected] https://www.ietf.org/mailman/listinfo/simple