<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On 8 Dec 2013, at 10:40, Sebastian Moeller <<a href="mailto:moeller0@gmx.de">moeller0@gmx.de</a>> wrote:</div><blockquote type="cite"><font color="#000000">...</font><br><span class="Apple-tab-span" style="white-space:pre"> </span>Is that really true? given enough concurrent flows, critical flows might be delayed purely be the round robin scheduling of equally "worthy" packets in fq_codel, so some residual priory system might still make sense…</blockquote></div><div><br></div><div>Sebastian - you are describing a property that we've measured in large scale (countrywide) deployed networks, it is also the underlying property that is causing mobile network operators issues with packet based networks as backhaul, as well as several other mission critical environments we've had dealings with.</div><div><br></div><div>When I pointed out that such service approaches will create extreme non-stationarity (in the particular case 2+ seconds) - the designers said - not their problem, not in their brief from management, they were told to bandwidth share.</div><div><br></div><div>It is not just that the 2+ seconds can exist, but that the overall system (under the right offered traffic pattern) WILL display that dynamic property.</div><div><br></div><div>Neil</div><div><br></div></body></html>