[R-C] Charter update

Michael Welzl michawe at ifi.uio.no
Mon Aug 13 09:40:21 CEST 2012


Folks,

I sense a lot of tacit approval  ;-)

Is this now ready to be shipped to the IESG?


Okay, I'm trying to be provocative, to get some feedback... but seriously, I think that there wasn't a lot of debate (in the sense of disagreement) about the charter, just constructive suggestions. I do believe that I have incorporated most, if not all of them in this version. So I'd like to try using a deadline: could we say that I ship this off on Wednesday 15 August unless I receive suggestions for changes by then?

Cheers,
Michael



On 10. aug. 2012, at 13:02, Michael Welzl wrote:

> See below for an update of the charter:
> 
> - some minor fixes, e.g. wording in the list of deliverables
> - the most significant change: updated milestone list
> 
> Comments?
> 
> Cheers,
> Michael
> 
> 
> *******************************************************************************************
> 
> 
> RTP Media Congestion Avoidance Techniques (rmcat)
> 
> Status: Proposed Working Group
> Last Updated: 2012-08-10
> 
> Chair(s):
> TBD
> 
> Transport Area Director(s):
> Wesley Eddy <wes at mti-systems.com>
> 
> Transport Area Advisor:
> Wesley Eddy <wes at mti-systems.com>
> 
> Mailing Lists: TBD (until establishment, we use rtp-congestion at alvestrand.no)
> 
> Description of Working Group
> 
> In today's current internet, part of the traffic is delivery of interactive real time media, often in the form of sets of media flows using RTP over UDP.
> There is no generally accepted congestion control mechanism for this kind of data flow.
> With the deployment of applications using the RTCWEB protocol suite, the number of such flows is likely to increase, especially non-fixed-rate flows such as video or adaptive audio. There is therefore some urgency in specifying one or more congestion control mechanisms that can find general acceptance.
> 
> Congestion control algorithms for interactive real time media may need to be quite different from the congestion control of TCP: for example, some applications can be more tolerant to loss than delay and jitter. The set of requirements for such an algorithm includes, but is not limited to:
> 	• Low delay and low jitter for the case where there is no competing traffic using other algorithms
> 	• Reasonable share of bandwidth when competing with RMCAT traffic, other real-time media protocols, and ideally also TCP and other protocols
> 	• Effective use of signals like packet loss and ECN markings to adapt to congestion
> 
> The working group will:
> 	• Develop a clear understanding of the congestion control requirements for RTP flows, and document deficiencies of existing mechanisms such as TFRC with regards to these requirements.
> 	• Define interactions between applications and RTP flows to enable specifying requirements such as per-packet priorities.
> 	• Determine if there is an appropriate means to define standard RTP/RTCP extensions for carrying congestion control feedback, similar to how DCCP defines congestion control mechanisms, and if so, document such extensions as standards-track RFCs.
> 	• Develop techniques to detect, instrument or diagnose failing to meet RT schedules due to failures of components outside of the charter scope, possibly in collaboration with IPPM.
> 	• Develop a mechanism for identifying and controlling groups of flows.
> 	• Define evaluation criteria for proposed mechanisms, and publish these as an Informational RFCs.
> 	• Find or develop candidate congestion control algorithms, verify that these can be tested on the Internet without significant risk, and publish one or more of these as Experimental RFCs.
> 	• Publish evaluation criteria and the result of experimentation with these Experimental algorithms on the Internet
> 	• Once an algorithm has been found or developed that meets the evaluation criteria, and has a satisfactory amount of documented experience on the Internet, publish this algorithm as a Standards Track RFC. There may be more than one such algorithm.
> 
> The work will be guided by the advice laid out in RFC 5405 (UDP usage guidelines) and RFC 2914 (congestion control principles).
> 
> The following topics are out of scope:
> 	• Circuit-breaker algorithms for stopping media flows when network conditions render them useless; this work is done in AVTCORE;
> 	• Media flows for non-interactive purposes like stored video playback; those are not as delay sensitive as interactive traffic;
> 	• Defining active queue management; modifications to TCP of any kind; and
> 	• Multicast congestion control (common control of multiple unicast flows is in scope).
> 	• Topologies other than point-to-point connections. Implications on multi-hop connections will be considered at a later stage.
> 
> The working group is expected to work closely with the RAI area, including the underlying technologies being worked on in the AVTCORE and AVTEXT WGs, and the applications/protocol suites being developed in the  CLUE and RTCWEB working groups.
> It will also liaise closely with other Transport area groups working on congestion control, and with the Internet Congestion Control Research Group of the IRTF.
> 
> Deliverables
> 	• Requirements for congestion control algorithms for interactive real time media - Informational RFC
> 	• Evaluation criteria for congestion control algorithms for interactive real time media - Informational RFC
> 	• RTCP extensions for use with congestion control algorithms - Standards-track RFC
> 	• Interactions between applications and RTP flows - Informational RFC
> 	• Identifying and controlling groups of flows - Standards-track RFC
> 	• Techniques to detect, instrument or diagnose failing to meet RT schedules - Informational RFC
> 	• Candidate congestion control algorithm for interactive real time media - Experimental RFCs (likely more than one)
> 	• Experimentation and evaluation results for candidate congestion control algorithms - Informational RFC
> 	• A recommended congestion control algorithm for interactive real time media - Standards-track RFC
> 
> Milestones
> 	• NN NNNA: (chartering + 1 month) Publish first drafts of requirements and evaluation criteria
> 	• NN NNNB: (=A) publish first drafts of RTCP extensions for use with congestion control algorithms and interactions between applications and RTP flows
> 	• NN NNNC: Adopt first congestion control candidate as WG draft
> 	• NN NNND: (B + 2 months) Publish first draft of identifying and controlling groups of flows
> 	• NN NNNE: (A + 4 months) Submit requirements and evaluation criteria to IESG as Informational
> 	• NN NNNF: (B + 6 months) Submit RTCP extensions for use with congestion control algorithms to IESG for Standards-track publication, and submit interactions between applications and RTP flows to IESG as Informational
> 	• NN NNNG: (E + 2 months) Submit first congestion control candidate to IESG for Experimental publication
> 	• NN NNNH: (D + 6 months) Submit identifying and controlling groups of flows to IESG for Standards-track publication
> 	• NN NNNI: (G + 3 months) First draft of evaluation results
> 	• NN NNNJ: (=I) First draft of standards-track congestion control
> 	• NN NNNK: (=J) First draft of techniques to detect, instrument or diagnose failing to meet RT schedules
> 	• NN NNNL: (K + 6 months) Submit techniques to detect, instrument or diagnose failing to meet RT schedules to IESG as Informational
> 	• NN NNNM: (J + 8 months) Submit congestion control to IESG for Proposed Standard
> (time from chartering to end of charter is 18 months)
> 
> 
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