Re: [MMUSIC] POF/PAN: SDP group attribute in a POF/PAN?

On Mon, Oct 21, 2013 at 1:00 PM, Christer Holmberg <
christer.holmberg@ericsson.com> wrote:

>  Hi,
>
>
>
> >> one also needs to specify the location of the m- line mid value in the
> >> group:BUNDLE mid value list.
> >
> > I don't believe that's true.
> >
> > The only ordering consideration that I'm aware of for group:BUNDLE is
> > that the first indicated mid is the one that the transport information
> > is taken from.
>
>
>
> If, for whatever reason, the Answerer does not/cannot choose the first in
> the list, it shall try the next in the list, etc.
>
>
>
> But, that only becomes an issue when the BUNDLE address has yet not been
> negotiated - or when one tries to re-negotiate it (discussed below).
>
>
>
> > By the time we're into partial exchanges, the transport
> > information for all the lines in the same bundle should be identical.
>
>
>
> ...assuming we don't also want to re-negotiate the BUNDLE address with the
> POF, in which case the POF might contain that new address.
>
>
>
> But, as we discussed earlier, and as you also indicated at the end of your
> e-mail, maybe using POF for transport re-negotiation is something we can
> disallow.
>
+1. Another side affect with this is, if the POF corresponds to m=line
whose mid is the first entry in the a=group:BUNDLE and this POF changes the
C= and Port field. Even in this, the BUNDLE draft might want to add a
requirement that it is disallowed for POF/PAN scenario.

> > To ensure a common view of groups, we probably want to define things
> > such that new lines added to a group are appended to the list. Is there
> > any reason you can think this doesn't work for BUNDLE?
>
> I need to think about it, but nothing comes to my mind at the moment.
>
>
>
> And, if both endpoints add a new m- line to the BUNDLE group at the same
> time, I guess the order in which they mids are appended to the list could
> be based on the order in which the m- lines themselves are added to the SDP
> state.
>

The draft discusses on the rules to append the m=lines based on the
lexically ordering of their mid values and the same rules applies here as
well. This would form common view in this case.

>
> > To be clear, let's set aside the prospect of changing transport
> > addresses for a BUNDLE: I don't think it's unreasonable to require a
> > full offer/answer exchange to do that kind of thing.
>
>
>
> I agree.
>
>
>
> Regards,
>
>
>
> Christer
>
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