I'd be okay with exponential-smoothing. It's better than what is there. Not quite as good as moving average. Brian > -----Original Message----- > From: sipping-bounces@xxxxxxxx [mailto:sipping-bounces@xxxxxxxx] On > Behalf Of Dale Worley > Sent: Thursday, February 05, 2009 5:13 PM > To: SIPPING > Subject: Comments on draft-niemi-sipping-event-throttle- > 07.txt > > The concept is interesting. I think that the draft could be improved > in some ways: > > - The names of the parameters are not so easy to remember. I would > suggest "min", "max", and "average". > > - More thought probably needs to be put into the real algorithm, which > accommodates possibly having all 3 parameters set, as well as various > subsets. > > - I expect it would be useful to have more explicit language specifying > how the subscriber requests particular parameters, how the notifier > agrees or not to those values, how they get un-set, etc. It seems that > a request/response negotiation is expected, and there are a lot of grey > areas, but I think it would help to explicate the possibilities. > > - Similarly, language should be added to make it clear that the > notifier SHOULD do what is asked, and the subscriber needs to be > prepared for behavior much different from what is asked. > > - In regard to averaging, it turns out that you can make a spreadsheet > to apply the average rule. For example, the attached spreadsheet (if > it comes through), is the case: average = 10 sec, period = 100 sec, an > initial event at 0 sec. The graph panel shows the successive timeout > values. You can change the average and period values and the > spreadsheet will update the results. > > - A little fiddling suggests that setting period to 10*average gives > good results -- the timeout values quickly converge to the desired > interval. Plugging that into the formula of section 6.2 gives > > timeout = average * (count of notifications in last 10*average) / 10 > > - Brian Rosen suggests a moving average instead of the interval-count. > But an easier formula to implement is an exponential-smoothing formula: > > timeout = > (1 + alpha - beta) * (last timeout value) > - alpha * (interval since last notification) > + beta * average > > That has the same general properties -- if a stimulated event causes > the interval since the last notification to be small, it increases > timeout for the next few notifications. But it requires remembering > only two numbers about the past: the last timeout and the time of the > last notification. > > Dale _______________________________________________ Sipping mailing list https://www.ietf.org/mailman/listinfo/sipping This list is for NEW development of the application of SIP Use sip-implementors@xxxxxxxxxxxxxxx for questions on current sip Use sip@xxxxxxxx for new developments of core SIP
