Re: [AVTCORE] I-D Action: draft-ietf-avtcore-rtp-circuit-breakers-01.txt

[Kevin Gross <[e-mail]>]

Because the circuit breaker is conservative, my assessment is that things
are clearly badly busted when the breaker trips. In this case, over the
duration of 3 RRs, not a single RTP packet has been delivered. If this is
due to moderate congestion or flow control, you'd expect at least a few of
the packets to get through. If none are getting through, there is either a
connectivity problem or possibly congestive collapse. In neither case is
reducing rate by a factor of 10 a useful response. Have I missed something?
What sort of failure scenario are you thinking of where the reduced rate
would be successful?

I am also concerned about scope. Circuit breakers are a safety net and
should not interfere with congestion management techniques as they are
developed. Circuit breakers should conservatively detect faults and trip.
They should not half-trip or automatically reset themselves.

On Tue, Feb 12, 2013 at 5:18 PM, Colin Perkins <[e-mail]> wrote:

> Section 4.1: Delete second paragraph. As disused in the session today, if
> things are messed up enough to trigger circuit breaker #1, reducing offered
> load is not likely a useful response. Section 4.3 contains a copy of this
> recommendation and is probably an appropriate recommendation for circuit
> breaker #3 described there.
>
>
> If this were a congestion control algorithm, I'd probably agree that we
> should be more aggressive in stopping transmission here, but the circuit
> breaker is supposed to be conservative when it fires, to encompass all
> reasonable congestion control behaviours. As such, I think it is better
> that the draft allow the option of reducing offered load as a response
> here, rather than mandate ceasing transmission immediately.
>
>