Re: [Dart] draft-dart-dscp-rtp - way forward

["Black, David" <[e-mail]>]

Harald,

I'm about to submit a -05 with the indication that the single DSCP recommendation
for SCTP and DCCP may be revised.  The RTCP multi-stream optimization text will
still be in there with Colin's clarification about "received" streams.  I'm about
to vanish for about 3 weeks, but could put in a revised -06 over the weekend 
if you can quickly convince Colin.

Thanks,
--David

> -----Original Message-----
> From: Harald Alvestrand [mailto:[e-mail]]
> Sent: Friday, August 29, 2014 6:49 AM
> To: Ben Campbell; Black, David
> Cc: [e-mail]
> Subject: Re: [Dart] draft-dart-dscp-rtp - way forward
> 
> I think the text in -04 looks reasonable.
> 
> I would like to do two things:
> 
> - The justification for "single DSCP" in SCTP and DCCP is "we don't know
> what will happen".
> A logical consequence is that this recommendation might change as the
> result of further study, so we might want to add near the bottom of
> section 5 a sentence saying "This recommendation may be revisited if
> experiments and analysis shows compelling reasons to change it."
> 
> - I still think the ban against RTCP multi-stream reporting optimization
> is completely wrong. The reports will correctly reflect the differing
> packet loss behaviours of the incoming RTP streams, and that's all they
> should be required to do.
> 
> I regard the latter as somewhat important. The former is more a matter
> of taste (if we're arguing based on ignorance, allow for the case where
> ignorance becomes knowledge).
> 
> 
> On 08/28/2014 10:25 PM, Ben Campbell wrote:
> > Okay, works for me.
> >
> > Thanks!
> >
> > Ben.
> >
> > On Aug 28, 2014, at 3:15 PM, Black, David <[e-mail]> wrote:
> >
> >>> If we think we can close this as not a real issue (or at least not an
> issue we
> >>> plan to address), but there's some risk it might come back up at IETF LC,
> then
> >>> that's fine. But if we are saying there is an open issue that needs
> closure,
> >>> but we can close it during IETF last call, then I have reservations. The
> >>> version that goes to IETF LC should be one that the working group believes
> to
> >>> be as complete is it's going to get.
> >> In private discussion, both Harald and I favored saying less (rather than
> more)
> >> about RMCAT in this DART draft.  For that reason I think "at least not
> >> an issue we plan to address" is a valid characterization of this item.
> >>
> >> Thanks,
> >> --David
> >>
> >>> -----Original Message-----
> >>> From: Ben Campbell [mailto:[e-mail]]
> >>> Sent: Thursday, August 28, 2014 3:44 PM
> >>> To: Black, David; Harald Tveit Alvestrand
> >>> Cc: [e-mail]
> >>> Subject: Re: [Dart] draft-dart-dscp-rtp - way forward
> >>>
> >>> (as chair)
> >>>
> >>> On Aug 28, 2014, at 1:12 PM, Black, David <[e-mail]> wrote:
> >>>
> >>>> [E] Open issue: Harald Alvestrand's concerns about "differential
> treatment"
> >>>> wrt Section 5.1 .  I don't completely understand these concerns, and
> suspect
> >>>> that they may require an email discussion across the DART and RMCAT WGs
> >>>> to sort through.
> >>>>
> >>>> --> Deferred - Harald wanted to think about this, and I've seen nothing
> >>>> --> further.  I'd suggest that IETF Last Call as an appropriate
> opportunity
> >>>> --> to share any further thoughts, so I don't think there's anything to
> be
> >>> done
> >>>> --> about this now.
> >>> I have mixed feelings on this.
> >>>
> >>> If we think we can close this as not a real issue (or at least not an
> issue we
> >>> plan to address), but there's some risk it might come back up at IETF LC,
> then
> >>> that's fine. But if we are saying there is an open issue that needs
> closure,
> >>> but we can close it during IETF last call, then I have reservations. The
> >>> version that goes to IETF LC should be one that the working group believes
> to
> >>> be as complete is it's going to get.
> >>>
> >>> David, thoughts?
> >>>
> >>> Harald, do you care to comment further?