Re: [siprec] Can an MS object span several CSs in a CSG?

["Elwell, John" <[e-mail]>]

 

> -----Original Message-----
> From: Parthasarathi R (partr) [mailto:[e-mail]] 
> Sent: 24 May 2011 23:14
> To: Charles Eckel (eckelcu); Ram Mohan R (rmohanr); Elwell, 
> John; [e-mail]
> Subject: RE: [siprec] Can an MS object span several CSs in a CSG?
> 
> Hi Charles,
> 
> One of the usecase in my mind is discussed in
> http://www.ietf.org/mail-archive/web/siprec/current/msg01890.html. The
> details are as follows:
> 
> B2BUA acts as SRC. A, B, C are participants within single B2BUA. A
> creates single RS for a CSG.
> 
> 1) A calls B through B2BUA. B2BUA creates RS towards SRS with 
> CSG1, CS1,
> MS1 (A's media stream), MS2 (B's media stream), Participant1 as A &
> Participant2 as B.
> 2) B connects with C through B2BUA
> 3) B transfer the call of A & B to C using REFER, B2BUA converts REFER
> to RE-INVITE towards A & C and A & C are connected. B2BUA updates RS
> with CS2, Participant1 as A & participant2 as C, MS1(A's 
> media stream),
> MS2(C's media stream). There is no update on RS1, CSG1, MS1, MS2. MS2
> will become MS2 with the new association and in terms of 
> format, it will
> associate with <send> tag
[JRE] What harm is done (what do we lose) if, following transfer, A's media stream is called MS3 and C's media stream is called MS4? MS3 can reference the same SDP m-line (through a=label) as MS1, and likewise MS4 could reference the same SDP m-line as MS2, if we are concerned about recycling media descriptions in RS SDP.

John (as individual)

> 
> Thanks
> Partha  
> 
> -----Original Message-----
> From: Charles Eckel (eckelcu) 
> Sent: Wednesday, May 25, 2011 1:39 AM
> To: Ram Mohan R (rmohanr); Parthasarathi R (partr); 'Elwell, John';
> '[e-mail]'
> Subject: RE: [siprec] Can an MS object span several CSs in a CSG?
> 
> Hi Ram,
> 
> I think that is many cases, they will be treated as separate 
> MSs due to
> the complexities you mention. However, I am trying to understand if
> Partha feels allowing an SRC to treat them as a single MS is still
> required. If not, then what is a use case? A concrete example 
> would help
> me, and potentially others, to better understand the motivation behind
> Partha's requirement for modeling media from multiple CSs as a single
> MS.
> 
> Cheers,
> Charles
> 
> > -----Original Message-----
> > From: Ram Mohan R (rmohanr)
> > Sent: Tuesday, May 24, 2011 9:36 AM
> > To: Charles Eckel (eckelcu); Parthasarathi R (partr); Elwell, John; 
> > [e-mail]
> > Subject: RE: [siprec] Can an MS object span several CSs in a CSG?
> > 
> > Charles,
> > 
> > I did bring about this specific usecase of MMOH/MOH stream being 
> > played to different participants earlier and suggested that 
> they have 
> > to treated as a same MS across multiple CSs (potentially recorded
> using multiple RSs).
> > Refer 
> > http://www.ietf.org/mail-archive/web/siprec/current/msg01886.html
> > 
> > We had several discussions on it and it and several folks were in 
> > favor of treating it as separate MS as there would be 
> complexity in DB
> design.
> > 
> > Regards,
> > Ram
> > 
> > 
> > > -----Original Message-----
> > > From: [e-mail] [mailto:[e-mail]] On 
> > > Behalf Of Charles Eckel (eckelcu)
> > > Sent: Tuesday, May 24, 2011 9:11 PM
> > > To: Parthasarathi R (partr); Elwell, John; [e-mail]
> > > Subject: Re: [siprec] Can an MS object span several CSs in a CSG?
> > >
> > > Hi Partha,
> > >
> > > Is an example of this the same music on hold audio stream 
> existing 
> > > as the same MS within multiple CSs? If so, then I understand your 
> > > requirement to be that the SRC be able to indicate multiple 
> > > instances of this audio stream within several CSs as 
> being the same 
> > > MS. Is that correct?
> > >
> > > Thanks,
> > > Charles
> > >
> > > > -----Original Message-----
> > > > From: [e-mail] 
> [mailto:[e-mail]] On
> > > Behalf Of Parthasarathi R (partr)
> > > > Sent: Tuesday, May 24, 2011 4:26 AM
> > > > To: Elwell, John; [e-mail]
> > > > Subject: Re: [siprec] Can an MS object span several CSs 
> in a CSG?
> > > >
> > > > John,
> > > >
> > > > I agree that it is not mandatory to consider recorded 
> stream of a 
> > > > specific participant in several CS within the same CSG as one
> > > recorded
> > > > stream but SIPREC protocol design MUST NOT restrict a 
> SRC in case 
> > > > it wishes to design in such a way.
> > > >
> > > > Thanks
> > > > Partha
> > > >
> > > > -----Original Message-----
> > > > From: [e-mail] 
> [mailto:[e-mail]] On
> > > Behalf
> > > > Of Elwell, John
> > > > Sent: Tuesday, May 24, 2011 1:06 PM
> > > > To: [e-mail]
> > > > Subject: [siprec] Can an MS object span several CSs in a CSG?
> > > >
> > > > We seem to have consensus that a Media Stream object 
> represents a 
> > > > recorded media stream, contributed to by one, several or all 
> > > > Participants. However, Partha also wrote:
> > > >
> > > > "2) Each MS lifetime related to CSG because participant 
> may move 
> > > > from one CS to another CS within single CSG and also 
> CSG will span
> 
> > > > across multiple RS."
> > > >
> > > > I am not sure we had resolved this during earlier 
> discussions on 
> > > > the scope of an MS object. Although the same Participant can 
> > > > participate
> > > in
> > > > several CSs within the same CSG, I don't think the 
> recorded media 
> > > > streams need to be considered the same. Any other views?
> > > >
> > > > John (as individual)
> > > > _______________________________________________
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