<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">+1 on measuring the latency on the load-generating connections.<div class=""><br class=""></div><div class=""><br class=""></div><div class="">Christoph<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On May 13, 2022, at 12:48 AM, Sebastian Moeller <<a href="mailto:moeller0@gmx.de" class="">moeller0@gmx.de</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta charset="UTF-8" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Hi Carl,</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><blockquote type="cite" style="font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">On May 12, 2022, at 23:04, Klatsky, Carl via Bloat <<a href="mailto:bloat@lists.bufferbloat.net" class="">bloat@lists.bufferbloat.net</a>> wrote:<br class=""><br class="">Its good that they are running the latency test also during the load test, but from what it looks like, they seem to be running the latency test to the same server as the load test. I think a more realistic test is to run the load test to one server and the latency test to a different server. That's a more realistic use case...<br class=""></blockquote><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span class="Apple-tab-span" style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: pre; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"> </span><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">The question boils down to what "latency-under-load" should be measured here:</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">a) latency of different flows/hosts</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">b) latency of the load bearing flow(s)</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">both are informative, but if I had to choose I would ask Ookla for b), because running mtr/gping in parallel to a speedtest is comparatively easy compared to post-hoc deducing latency in the load bearing connection*... (I would assume that from a packet capture one might be able to piece this together when looking at the delay between sending a segment and receiving that matching ACK, which is more hassle than running e.g. "mtr -ezb4 --order LSNBAWVJMXI 8.8.8.8" ;) )<span class="Apple-converted-space"> </span></span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Regards</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span class="Apple-tab-span" style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: pre; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"> </span><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Sebastian</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">*) Well, there are pping (</span><a href="https://github.com/pollere/pping" style="font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" class="">https://github.com/pollere/pping</a><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">) and DlyLoc (</span><a href="https://github.com/pollere/DlyLoc" style="font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" class="">https://github.com/pollere/DlyLoc</a><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">), but so far I have not tried to make these run on my router (probably should start on an endhost first).</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><blockquote type="cite" style="font-family: Menlo-Regular; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br class="">Regards,<br class="">Carl Klatsky<br class=""><br class="">-----Original Message-----<br class="">From: Bloat <<a href="mailto:bloat-bounces@lists.bufferbloat.net" class="">bloat-bounces@lists.bufferbloat.net</a>> On Behalf Of Christoph Paasch via Bloat<br class="">Sent: Thursday, May 12, 2022 4:01 PM<br class="">To: <a href="mailto:nichols@pollere.net" class="">nichols@pollere.net</a><br class="">Cc: <a href="mailto:bloat@lists.bufferbloat.net" class="">bloat@lists.bufferbloat.net</a><br class="">Subject: Re: [Bloat] Ookla - Introducing a Better Measure of Latency<br class=""><br class="">I'm not aware of any rigorous study. But, just from the code, I know ICMP ping in many cases has a different traffic-class and thus implicitly gets quite a different treatment than real traffic.<br class=""><br class="">However, Ookla uses TCP (port 8080) to probe the latency in their app.<br class=""><br class=""><br class="">Christoph<br class=""><br class=""><blockquote type="cite" class="">On May 12, 2022, at 12:44 PM, Kathleen Nichols <<a href="mailto:nichols@pollere.net" class="">nichols@pollere.net</a>> wrote:<br class=""><br class="">a ping by any other name...<br class=""><br class="">Has anyone ever done a rigorous study to see how well ping delays correspond to the delay that information-carrying packets experience?<br class=""><br class="">On 5/12/22 10:15 AM, Christoph Paasch via Bloat wrote:<br class=""><blockquote type="cite" class="">Ookla's measure of "loaded latency":<br class=""><a href="https://urldefense.com/v3/__https://www.ookla.com/articles/introducin" class="">https://urldefense.com/v3/__https://www.ookla.com/articles/introducin</a><br class="">g-loaded-latency__;!!CQl3mcHX2A!DHnGDBw2sqsRwHiidAQUOhjXEavZmBOtJKb_IzPhxMm2vqUPyRC2pkVnScJId_KdaNVLsOS7sD0E8QRQ0m8B7LqBavY$ <https://urldefense.com/v3/__https://www.ookla.com/articles/introducing-loaded-latency__;!!CQl3mcHX2A!DHnGDBw2sqsRwHiidAQUOhjXEavZmBOtJKb_IzPhxMm2vqUPyRC2pkVnScJId_KdaNVLsOS7sD0E8QRQ0m8B7LqBavY$ > This will hopefully be a shift in how operators approach the bufferbloat problem.<br class="">Christoph<br class="">_______________________________________________<br class="">Bloat mailing list<br class="">Bloat@lists.bufferbloat.net<br class="">https://urldefense.com/v3/__https://lists.bufferbloat.net/listinfo/bl<br class="">oat__;!!CQl3mcHX2A!DHnGDBw2sqsRwHiidAQUOhjXEavZmBOtJKb_IzPhxMm2vqUPyR<br class="">C2pkVnScJId_KdaNVLsOS7sD0E8QRQ0m8BllXPjdw$<br class=""></blockquote><br class="">_______________________________________________<br class="">Bloat mailing list<br class=""><a href="mailto:Bloat@lists.bufferbloat.net" class="">Bloat@lists.bufferbloat.net</a><br class="">https://urldefense.com/v3/__https://lists.bufferbloat.net/listinfo/blo<br class="">at__;!!CQl3mcHX2A!DHnGDBw2sqsRwHiidAQUOhjXEavZmBOtJKb_IzPhxMm2vqUPyRC2<br class="">pkVnScJId_KdaNVLsOS7sD0E8QRQ0m8BllXPjdw$<br class=""></blockquote><br class="">_______________________________________________<br class="">Bloat mailing list<br class=""><a href="mailto:Bloat@lists.bufferbloat.net" class="">Bloat@lists.bufferbloat.net</a><br class="">https://urldefense.com/v3/__https://lists.bufferbloat.net/listinfo/bloat__;!!CQl3mcHX2A!DHnGDBw2sqsRwHiidAQUOhjXEavZmBOtJKb_IzPhxMm2vqUPyRC2pkVnScJId_KdaNVLsOS7sD0E8QRQ0m8BllXPjdw$<br class="">_______________________________________________<br class="">Bloat mailing list<br class=""><a href="mailto:Bloat@lists.bufferbloat.net" class="">Bloat@lists.bufferbloat.net</a><br class=""><a href="https://lists.bufferbloat.net/listinfo/bloat" class="">https://lists.bufferbloat.net/listinfo/bloat</a></blockquote></div></blockquote></div><br class=""></div></body></html>