<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">I met with the FreeNet Liberec admins earlier this week, and am just starting to get the first IRTT / SmokePing probe data from a few backhaul routers. I’ll see if I can get snapshots of the SmokePing pages public somewhere, but for now...<div class=""><br class=""></div><div class=""><a href="https://www.heistp.net/downloads/jerab_ping.pdf" class="">https://www.heistp.net/downloads/jerab_ping.pdf</a></div><div class=""><br class=""><div class=""><div class=""><a href="https://www.heistp.net/downloads/jerab_irtt.pdf" class="">https://www.heistp.net/downloads/jerab_irtt.pdf</a></div><div class=""><br class=""></div><div class="">On this router, there are various “events” that occur with RTT spikes, and in general, UDP RTT maximums appear quite a bit higher than those for ICMP. I speculate that at least some of these events may be bloat, but can’t be sure yet.</div><div class=""><br class=""></div><div class="">This router is an old ALIX with kernel 2.6.26, but on the other hand it does have hfsc + esfq (a variant of sfq with host fairness) deployed, so if it’s actually controlling the queue, one might suspect that sfq it could control inter-flow latency at least somewhat.</div><div class=""><br class=""></div><div class="">I feel the need for better data than this, but this is at least a first look for me at bloat in an ISP’s backhaul. The “elaborate” plan is to gather data for a while, deploy sqm in a couple places (I hope for cake, but the kernel will need to be upgraded on this one), and see what happens… :)</div><div class=""><br class=""></div><div class="">Pete</div></div></div><div class=""><br class=""></div></body></html>