Pre-Congestion Notification (PCN) Architecture

Note: This ballot was opened for revision 09 and is now closed.

(David Ward) Discuss

Discuss (2009-02-24 for -)
This idea appears to have the issue that if the variance introduced by new sessions coming on exceeds the tolerance in the marking zone (eg, if there is plenty of capacity for one HDTV stream but not enough for two, and someone turns on a second TV while the first is watching a show), that can impact the application in the existing channel. The simulations have tested the ability of the system to operate when properly operated and properly configured; they have not seriously considered avalanche scenarios.

Avalanche scenarios are a variation of the "mother's day" problem, on a millisecond time scale; in real time applications such as voice and especially video it is possible to outrun an essentially infinite bandwidth pool during short time scales. Consider concerns with realtime video conferencing and the very careful planning  to ensure that the network can handle that class of traffic - on a 45 MBPS link with three data streams that nominally run 5 MBPS standing and ~12 MBPS at peaks (I-frame). There are demonstrated issues in picture quality due to conniption fits in the network and as a result force  more careful traffic pacing.

I think this is fine in parts of the network where avalanche scenarios are unusual but, that has to be clearly stated and that the idea does not work in other use cases.

(Lars Eggert) Yes

(Ron Bonica) (was Discuss) No Objection

(Ross Callon) (was Discuss) No Objection

(Pasi Eronen) (was Discuss) No Objection

(Adrian Farrel) (was Discuss) No Objection

Comment (2009-04-03)
Clearing my Discuss now I have found Section 12.3.

Can I suggest that you rebrand sections 12 and 13 not as appendixes. Also that you so not use the first person plural in the text of secition 12. I think the RFC is supposed to represent at least WG consensus and so the first person is a little ambiguous.

(Russ Housley) No Objection

Comment (2009-02-23 for -)
  The Gen-ART Review by Francis Dupont on 2009-02-23 provides many
  minor suggestions.  Please review them.

(Cullen Jennings) (was Discuss) No Objection

(Chris Newman) No Objection

(Dan Romascanu) (was Discuss) No Objection

(Mark Townsley) No Objection

(Magnus Westerlund) No Objection