<div dir="ltr"><div>Hi Sebastian, thank you for the feedback.</div><div><br></div><div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
"See the problem? Buffers produce jitter!"<br>
<br>
<br>
I would rephrase that as "over-sized and under-managed" buffers increase jitter unduly. Interestingly, bound jitter can be converted into static latency by using, wait for it, (delay) buffers and a scheduler.<br>
</blockquote><div><br></div><div>You are absolutely right. I was hoping someone would spot that! There is one problem with that approach though. To actually remove the jitter the scheduler can no longer be work-conserving (needs delay as you also point out), and that increases TCP ramp-up times (among other things). Can be a hard sell. I think the benefits outweigh the costs though, so I would do it your way.</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
> <br>
> Only nit is at the conclusion... the benefits of applying fair queuing<br>
> to level out apparent jitter is well demonstrated at this point, for<br>
> most kinds of traffic. Wish you'd mentioned it.<br>
<br>
I rather wish low latency DOCSIS (LLD) aka L4S's primary driver/use-case would not have been mentioned before it has been properly tested and confirmed delivering on its promises. Because most of what L4S offers/mandates for jitter reduction is "hopes and prayers", aka end-points are supposed to behave well... in fairness LLD at least has a poor man's FQ on board in the guise of "queue protection" (with by default like 32 "buckets")... some of the cost of FQ with only few of its benefits...<br></blockquote><div>Fair enough, time will show! <br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
Regards<br>
Sebastian<br>
<br>
<br>
<br>
> <br>
> <br>
> On Mon, Feb 14, 2022 at 7:07 AM Bjørn Ivar Teigen <<a href="mailto:bjorn@domos.no" target="_blank">bjorn@domos.no</a>> wrote:<br>
>> <br>
>> Hi everyone,<br>
>> <br>
>> I was inspired by the latest Starship presentation to write a piece on network quality in the language of rocket science. The blog can be found here: <a href="https://www.domos.no/news-updates/network-quality-for-rocket-scientists" rel="noreferrer" target="_blank">https://www.domos.no/news-updates/network-quality-for-rocket-scientists</a><br>
>> <br>
>> Cheers,<br>
>> Bjørn Ivar Teigen<br>
>> <br>
>> --<br>
>> Bjørn Ivar Teigen<br>
>> Head of Research<br>
>> +47 47335952 | <a href="mailto:bjorn@domos.no" target="_blank">bjorn@domos.no</a> | <a href="http://www.domos.no" rel="noreferrer" target="_blank">www.domos.no</a><br>
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> <br>
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</blockquote></div><br clear="all"><br>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><span style="background-color:rgb(255,255,255)"><span style="color:rgb(0,0,0)"><font size="2">Bjørn Ivar Teigen</font></span></span></div><div><span style="background-color:rgb(255,255,255)"><span style="color:rgb(0,0,0)"><font size="2">Head of Research<br></font></span></span></div><span style="background-color:rgb(255,255,255)"><span style="color:rgb(0,0,0)"><font size="2"><span style="font-family:arial,sans-serif"><span style="font-style:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;display:inline;float:none">+47 47335952 |<span> </span></span><a href="mailto:name@domos.no" rel="noopener noreferrer" style="text-decoration:none;font-style:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" target="_blank">bjorn@domos.no<span></span></a><span style="font-style:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;display:inline;float:none"><span> </span>|<span> </span></span><a href="http://www.domos.no/" rel="noopener noreferrer" style="text-decoration:none;font-style:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" target="_blank">www.domos.no</a></span><br style="font-family:Slack-Lato,appleLogo,sans-serif;font-style:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><span style="font-family:arial,sans-serif"><span style="font-style:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;display:inline;float:none">WiFi Slicing by Domos</span></span></font></span></span></div></div></div></div></div></div></div></div>