[R-C] RTCWEB Congestion Control Standardization

[Tim Panton]

On 10 Oct 2011, at 10:22, Magnus Westerlund wrote:

> Hi,
> 
> I want to lift an important non-technical topic for discussion. Namely,
> what is needed in the specifications and how to get that to happen.
> 
> 
> It is clear that RTCWEB can't be the home to specify any new congestion
> control algorithms or procedures. That needs to be defined elsewhere.
> 
> Looking at what is available from a specification point of view, I think
> the only that is fully specified for RTP is TFRC in DCCP.
> 
> The technical discussion appears to be desiring something else. Thus I
> think we need to have the discussion of how to get that written up in a
> specification eventually. What is the plan here? From my perspective we
> will need something that is acceptable to get the RTCWEB's RTP usage
> specification through IESG. Especially as we have identified clear
> security threats to no having congestion control in the browser part
> preventing significant over uses.
> 
> So what are our alternative here?
> 
> 1) Pick TFRC for now while developing something better? Possibly ensure
> that the RTP mapping gets published in a reasonable time frame.
> 
> 2) Try to write clear requirements on the implementation, but no
> specification and hopes that goes through?
> 
> 3) Develop something and delay the publication of any part that needs
> this until it is done?
> 
> 4) ?
> 
> Regarding 3), I don't see how that is going to complete in less than 2
> more likely 3 years. Spin up a TSV WG, develop a solution. Simulate and
> discuss corner cases for a while before getting good enough out.
> 
> So what are your views on this issue?

I would go for 2) 

If at all possible we should come up with requirements that are such
that they can be independently implemented at each end of the
P2P 'connection' - any necessary interaction between the ends should 
be part of a pre-existing specification (SRTP, RTCP or whatever) which
we can reference.

This would leave the browser vendors clear to implement those requirements
however they see fit while minimising risk of interop problems between
browsers.

I don't know if this is do-able from a technical standpoint.

Tim.