Re: [Bloat] Detecting bufferbloat from outside a node

[Neil Davies <neil.davies@pnsol.com>]

Toke


On 27 Apr 2015, at 15:22, Toke Høiland-Jørgensen <toke@toke.dk> wrote:

> Neil Davies <neil.davies@pnsol.com> writes:
> 
>> You'll find the way that ∆Q can be decomposed into basis set of ∆Q|G,
>> ∆Q|S and ∆Q|V - helps work out which parts of the budget get eaten up
>> by different elements of the network design/architecture.
> 
> Right, I got that part. What I'm missing is how you define the actual
> measure for ∆Q -- but that is application dependent? E.g. for web sites
> it might be load time, for VoIP it might be MOS score?
> 
> -Toke


For VoIP the aspects of ∆Q that are of interest (after the total one way delay) are the 
delay variance and loss rate - take a look at https://ivanovic.web.cern.ch/ivanovic/articles/open-2004-007.pdf 
(which is the tech report behind what was published in SPECTS'03 (Beuran, R., Ivanovici, M., Dobinson,
 B., Davies, N., Thompson, P.: Network Quality of Service Measurement System for
Application Requirements Evaluation)

In other aspects it might be "time to first frame" (VoD) or "possibility of a buffer starvation event per operating hour" (VoD)
the QoE (Qualty of Experience) metric needs to be one that has a relationship with the users' perception.]

Neil