Re: [MMUSIC] BUNDLE DECISSION: SDP Answer Restrictions

Hi Christer

  Please find my comments in line.

On Fri, May 24, 2013 at 5:32 AM, Christer Holmberg <
christer.holmberg@ericsson.com> wrote:

>  Hi,****
>
> ** **
>
> At the interim meeting yesterday, we agreed on some restrictions regarding
> creating SDP answers containing bundle group(s).****
>
> ** **
>
> Note that the restrictions 1-3 are simply alignments with RFC 5888, and
> are listed simply for clarification purpose. Restrictions 4 is BUNDLE
> specific. Restriction 5 is also alignment with RFC 5888, as m- lines with
> port zero are not allowed within groups, but we will need some
> clarification text saying that a new offer will have to be sent in order to
> remove a stream (either from a bundle group, or completely from the
> session).****
>
> ** **
>
> (Note that the text below is not necessarily the wording that will go into
> the draft)****
>
> ** **
>
> In an SDP answer:****
>
> **1)      **a BUNDLE group MUST NOT be created, unless it was included in
> the associated offer****
>
> **2)      **an m- line MUST NOT be added to a BUNDLE group, unless it was
> included in a BUNDLE group in the associated offer****
>
> **3)      **an m- line MUST NOT be added to another BUNDLE group than the
> group in which was included in the associated offer****
>
> **4)      **an m- line MUST NOT be removed from a BUNDLE group if, in the
> associated offer, an identical port number was indicated for all m- lines
> in a BUNDLE group****
>
> **
>
  [Suhas]  .. RFC5888 doesn't clarify what does removing means. Hence, I
would be happy to see 4)
                  If a m-line is removed ( not rejected) in the Answer,
then the m-line should include a unique port that doesn't collide with port
associated with any BUNDLE groups.

5)      **an m- line MUST NOT be rejected if, in the associated offer, an
> identical port number was indicated for all m- lines in a BUNDLE group****
>
> **
>
 [Suhas]. I agree with Paul here. Rejecting a m-line MUST be allowed by the
answerer by setting port to zero and removing mid from the BUNDLE group
attribute line. This is special case where BUNDLE should be satisfied if
            a) Either all the port are identical
            b) Ports in the BUNDLE group can be zero (if rejected).

>  **
>
> ** **
>
> Note that there is also a discussion regarding bundle offers, e.g. when
> restrictions when adding new m- lines to a bundle. Based on the outcome of
> that, there may be some additional answer restrictions, e.g. regarding the
> change of bundle transport parameters. But, let’s deal with that in the
> offer thread.
>

 [Suhas] Agreed.

> So, if anyone OBJECTS to the restrictions above, please indicate so.****
>
> ** **
>
> Regards,****
>
> ** **
>
> Christer****
>
> ** **
>
> ** **
>
> ** **
>
> ** **
>
> ** **
>
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