* [Rpm] Almost had a dialog going with juniper... @ 2023-02-19 23:02 Dave Taht 2023-02-19 23:34 ` rjmcmahon 0 siblings, 1 reply; 12+ messages in thread From: Dave Taht @ 2023-02-19 23:02 UTC (permalink / raw) To: Rpm https://blog.cerowrt.org/post/juniper/ But they deleted the comment thread. It is interesting, I suppose, to see how they frame the buffering problems to themselves in their post: https://www.linkedin.com/pulse/sizing-router-buffers-small-new-big-sharada-yeluri/ -- Surveillance Capitalism? Or DIY? Choose: https://blog.cerowrt.org/post/an_upgrade_in_place/ Dave Täht CEO, TekLibre, LLC ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Rpm] Almost had a dialog going with juniper... 2023-02-19 23:02 [Rpm] Almost had a dialog going with juniper Dave Taht @ 2023-02-19 23:34 ` rjmcmahon 2023-02-19 23:37 ` rjmcmahon 2023-02-19 23:40 ` Dave Taht 0 siblings, 2 replies; 12+ messages in thread From: rjmcmahon @ 2023-02-19 23:34 UTC (permalink / raw) To: Dave Taht; +Cc: Rpm Their post isn't really about bloat. It's about the discrepancy in i/o bw of memory off-chip and on-chip. My opinion is that the off-chip memory or hybrid approach is a design flaw for a serious router mfg. The flaw is thinking the links' rates and the chip memory i/o rates aren't connected when obviously they are. Just go fast as possible and let some other device buffer, e.g. the end host or the server in the cloud. Bob > https://blog.cerowrt.org/post/juniper/ > > But they deleted the comment thread. It is interesting, I suppose, to > see how they frame the buffering problems to themselves in their post: > https://www.linkedin.com/pulse/sizing-router-buffers-small-new-big-sharada-yeluri/ ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Rpm] Almost had a dialog going with juniper... 2023-02-19 23:34 ` rjmcmahon @ 2023-02-19 23:37 ` rjmcmahon 2023-02-19 23:44 ` Dave Taht 2023-02-19 23:40 ` Dave Taht 1 sibling, 1 reply; 12+ messages in thread From: rjmcmahon @ 2023-02-19 23:37 UTC (permalink / raw) To: rjmcmahon; +Cc: Dave Taht, Rpm A bit off topic, but the AP/client power asymmetry is another design flaw similar to bloat. Not sure why nobody is talking about that. https://www.youtube.com/watch?v=Ey5jVUXSJn4 Bob > Their post isn't really about bloat. It's about the discrepancy in i/o > bw of memory off-chip and on-chip. > > My opinion is that the off-chip memory or hybrid approach is a design > flaw for a serious router mfg. The flaw is thinking the links' rates > and the chip memory i/o rates aren't connected when obviously they > are. Just go fast as possible and let some other device buffer, e.g. > the end host or the server in the cloud. > > Bob >> https://blog.cerowrt.org/post/juniper/ >> >> But they deleted the comment thread. It is interesting, I suppose, to >> see how they frame the buffering problems to themselves in their post: >> https://www.linkedin.com/pulse/sizing-router-buffers-small-new-big-sharada-yeluri/ > _______________________________________________ > Rpm mailing list > Rpm@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/rpm ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Rpm] Almost had a dialog going with juniper... 2023-02-19 23:37 ` rjmcmahon @ 2023-02-19 23:44 ` Dave Taht 2023-02-19 23:52 ` rjmcmahon 0 siblings, 1 reply; 12+ messages in thread From: Dave Taht @ 2023-02-19 23:44 UTC (permalink / raw) To: rjmcmahon; +Cc: Rpm On Sun, Feb 19, 2023 at 3:37 PM rjmcmahon <rjmcmahon@rjmcmahon.com> wrote: > > A bit off topic, but the AP/client power asymmetry is another design > flaw similar to bloat. It makes no sense to broadcast at a watt when the device is nearby. I think this is a huge, and largely unexplored problem. We tried to tackle it in the minstrel-blues project but didn't get far enough, and the rate controllers became too proprietary to continue. Some details here: https://github.com/thuehn/Minstrel-Blues > > Not sure why nobody is talking about that. Understanding of the inverse square law is rare. The work we did at google fiber, clearly showed the chromecast stick overdriving nearby APs. https://apenwarr.ca/diary/wifi-data-apenwarr-201602.pdf > https://www.youtube.com/watch?v=Ey5jVUXSJn4 Haha. > > Bob > > Their post isn't really about bloat. It's about the discrepancy in i/o > > bw of memory off-chip and on-chip. > > > > My opinion is that the off-chip memory or hybrid approach is a design > > flaw for a serious router mfg. The flaw is thinking the links' rates > > and the chip memory i/o rates aren't connected when obviously they > > are. Just go fast as possible and let some other device buffer, e.g. > > the end host or the server in the cloud. > > > > Bob > >> https://blog.cerowrt.org/post/juniper/ > >> > >> But they deleted the comment thread. It is interesting, I suppose, to > >> see how they frame the buffering problems to themselves in their post: > >> https://www.linkedin.com/pulse/sizing-router-buffers-small-new-big-sharada-yeluri/ > > _______________________________________________ > > Rpm mailing list > > Rpm@lists.bufferbloat.net > > https://lists.bufferbloat.net/listinfo/rpm -- Surveillance Capitalism? Or DIY? Choose: https://blog.cerowrt.org/post/an_upgrade_in_place/ Dave Täht CEO, TekLibre, LLC ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Rpm] Almost had a dialog going with juniper... 2023-02-19 23:44 ` Dave Taht @ 2023-02-19 23:52 ` rjmcmahon 2023-02-20 0:02 ` rjmcmahon 0 siblings, 1 reply; 12+ messages in thread From: rjmcmahon @ 2023-02-19 23:52 UTC (permalink / raw) To: Dave Taht; +Cc: Rpm Cisco's first acquisition was Crescendo. They started with twisted pair and moved to Cat5. At the time, the claim was nobody would rewire corporate offices. But they did and those engineers always had an AC power plug nearby so they never really designed for power/bit over distance. Broadcom purchased Epigram. They started with twisted pair and moved to wireless (CMOS radios.) The engineers found that people really don't want to be tethered to wall jacks. So they had to consider power at all aspects of design. AP engineers have been a bit of a Frankenstein. They have power per AC wall jacks so the blast energy everywhere to sell sq ft. The enterprise AP guys do silly things like PoE. Better is to add CMOS radios everywhere and decrease power, inter-connected by fiber which is the end game in waveguides. Even the data centers are now limited to 4-meter cables when using copper and the energy consumption is through the roof. Bob > On Sun, Feb 19, 2023 at 3:37 PM rjmcmahon <rjmcmahon@rjmcmahon.com> > wrote: >> >> A bit off topic, but the AP/client power asymmetry is another design >> flaw similar to bloat. > > It makes no sense to broadcast at a watt when the device is nearby. I > think this is a huge, and largely unexplored problem. We tried to > tackle it in the minstrel-blues project but didn't get far enough, and > the rate controllers became too proprietary to continue. Some details > here: > > https://github.com/thuehn/Minstrel-Blues > >> >> Not sure why nobody is talking about that. > > Understanding of the inverse square law is rare. The work we did at > google fiber, clearly showed the chromecast stick overdriving nearby > APs. > > https://apenwarr.ca/diary/wifi-data-apenwarr-201602.pdf > > >> https://www.youtube.com/watch?v=Ey5jVUXSJn4 > > Haha. > >> >> Bob >> > Their post isn't really about bloat. It's about the discrepancy in i/o >> > bw of memory off-chip and on-chip. >> > >> > My opinion is that the off-chip memory or hybrid approach is a design >> > flaw for a serious router mfg. The flaw is thinking the links' rates >> > and the chip memory i/o rates aren't connected when obviously they >> > are. Just go fast as possible and let some other device buffer, e.g. >> > the end host or the server in the cloud. >> > >> > Bob >> >> https://blog.cerowrt.org/post/juniper/ >> >> >> >> But they deleted the comment thread. It is interesting, I suppose, to >> >> see how they frame the buffering problems to themselves in their post: >> >> https://www.linkedin.com/pulse/sizing-router-buffers-small-new-big-sharada-yeluri/ >> > _______________________________________________ >> > Rpm mailing list >> > Rpm@lists.bufferbloat.net >> > https://lists.bufferbloat.net/listinfo/rpm ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Rpm] Almost had a dialog going with juniper... 2023-02-19 23:52 ` rjmcmahon @ 2023-02-20 0:02 ` rjmcmahon 2023-02-20 17:56 ` Frantisek Borsik 0 siblings, 1 reply; 12+ messages in thread From: rjmcmahon @ 2023-02-20 0:02 UTC (permalink / raw) To: rjmcmahon; +Cc: Dave Taht, Rpm Here, look at this. Designed as a WiFi aggregation device. https://www.arista.com/en/products/750-series It supplies 60W PoE and claims support for 384 ports. Oh, the max distance per PoE AP is 100 meters. That's insane as a power source and the 100M distance limit is not viable. Our engineering needs to improve a lot. Bob > Cisco's first acquisition was Crescendo. They started with twisted > pair and moved to Cat5. At the time, the claim was nobody would rewire > corporate offices. But they did and those engineers always had an AC > power plug nearby so they never really designed for power/bit over > distance. > > Broadcom purchased Epigram. They started with twisted pair and moved > to wireless (CMOS radios.) The engineers found that people really > don't want to be tethered to wall jacks. So they had to consider power > at all aspects of design. > > AP engineers have been a bit of a Frankenstein. They have power per AC > wall jacks so the blast energy everywhere to sell sq ft. The > enterprise AP guys do silly things like PoE. > > Better is to add CMOS radios everywhere and decrease power, > inter-connected by fiber which is the end game in waveguides. Even the > data centers are now limited to 4-meter cables when using copper and > the energy consumption is through the roof. > > Bob >> On Sun, Feb 19, 2023 at 3:37 PM rjmcmahon <rjmcmahon@rjmcmahon.com> >> wrote: >>> >>> A bit off topic, but the AP/client power asymmetry is another design >>> flaw similar to bloat. >> >> It makes no sense to broadcast at a watt when the device is nearby. I >> think this is a huge, and largely unexplored problem. We tried to >> tackle it in the minstrel-blues project but didn't get far enough, and >> the rate controllers became too proprietary to continue. Some details >> here: >> >> https://github.com/thuehn/Minstrel-Blues >> >>> >>> Not sure why nobody is talking about that. >> >> Understanding of the inverse square law is rare. The work we did at >> google fiber, clearly showed the chromecast stick overdriving nearby >> APs. >> >> https://apenwarr.ca/diary/wifi-data-apenwarr-201602.pdf >> >> >>> https://www.youtube.com/watch?v=Ey5jVUXSJn4 >> >> Haha. >> >>> >>> Bob >>> > Their post isn't really about bloat. It's about the discrepancy in i/o >>> > bw of memory off-chip and on-chip. >>> > >>> > My opinion is that the off-chip memory or hybrid approach is a design >>> > flaw for a serious router mfg. The flaw is thinking the links' rates >>> > and the chip memory i/o rates aren't connected when obviously they >>> > are. Just go fast as possible and let some other device buffer, e.g. >>> > the end host or the server in the cloud. >>> > >>> > Bob >>> >> https://blog.cerowrt.org/post/juniper/ >>> >> >>> >> But they deleted the comment thread. It is interesting, I suppose, to >>> >> see how they frame the buffering problems to themselves in their post: >>> >> https://www.linkedin.com/pulse/sizing-router-buffers-small-new-big-sharada-yeluri/ >>> > _______________________________________________ >>> > Rpm mailing list >>> > Rpm@lists.bufferbloat.net >>> > https://lists.bufferbloat.net/listinfo/rpm > _______________________________________________ > Rpm mailing list > Rpm@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/rpm ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Rpm] Almost had a dialog going with juniper... 2023-02-20 0:02 ` rjmcmahon @ 2023-02-20 17:56 ` Frantisek Borsik 2023-02-20 18:27 ` Dave Taht 0 siblings, 1 reply; 12+ messages in thread From: Frantisek Borsik @ 2023-02-20 17:56 UTC (permalink / raw) To: rjmcmahon, Rpm [-- Attachment #1: Type: text/plain, Size: 4286 bytes --] What's the saddest thing for me is that the Juniper lady has acknowledged that Dave IS right and then she added those 2 AQM to the her article (where it should be), however, then she blocked me, and maybe even Dave, or others that were commenting on it? Besides the actual evaporating of those comments. Sad. I'd visit Your Los Gatos neighbor Bob, for a small talk, Dave ;-) All the best, Frank Frantisek (Frank) Borsik https://www.linkedin.com/in/frantisekborsik Signal, Telegram, WhatsApp: +421919416714 iMessage, mobile: +420775230885 Skype: casioa5302ca frantisek.borsik@gmail.com On Mon, Feb 20, 2023 at 1:02 AM rjmcmahon via Rpm <rpm@lists.bufferbloat.net> wrote: > Here, look at this. Designed as a WiFi aggregation device. > > https://www.arista.com/en/products/750-series > > It supplies 60W PoE and claims support for 384 ports. Oh, the max > distance per PoE AP is 100 meters. > > That's insane as a power source and the 100M distance limit is not > viable. > > Our engineering needs to improve a lot. > > Bob > > Cisco's first acquisition was Crescendo. They started with twisted > > pair and moved to Cat5. At the time, the claim was nobody would rewire > > corporate offices. But they did and those engineers always had an AC > > power plug nearby so they never really designed for power/bit over > > distance. > > > > Broadcom purchased Epigram. They started with twisted pair and moved > > to wireless (CMOS radios.) The engineers found that people really > > don't want to be tethered to wall jacks. So they had to consider power > > at all aspects of design. > > > > AP engineers have been a bit of a Frankenstein. They have power per AC > > wall jacks so the blast energy everywhere to sell sq ft. The > > enterprise AP guys do silly things like PoE. > > > > Better is to add CMOS radios everywhere and decrease power, > > inter-connected by fiber which is the end game in waveguides. Even the > > data centers are now limited to 4-meter cables when using copper and > > the energy consumption is through the roof. > > > > Bob > >> On Sun, Feb 19, 2023 at 3:37 PM rjmcmahon <rjmcmahon@rjmcmahon.com> > >> wrote: > >>> > >>> A bit off topic, but the AP/client power asymmetry is another design > >>> flaw similar to bloat. > >> > >> It makes no sense to broadcast at a watt when the device is nearby. I > >> think this is a huge, and largely unexplored problem. We tried to > >> tackle it in the minstrel-blues project but didn't get far enough, and > >> the rate controllers became too proprietary to continue. Some details > >> here: > >> > >> https://github.com/thuehn/Minstrel-Blues > >> > >>> > >>> Not sure why nobody is talking about that. > >> > >> Understanding of the inverse square law is rare. The work we did at > >> google fiber, clearly showed the chromecast stick overdriving nearby > >> APs. > >> > >> https://apenwarr.ca/diary/wifi-data-apenwarr-201602.pdf > >> > >> > >>> https://www.youtube.com/watch?v=Ey5jVUXSJn4 > >> > >> Haha. > >> > >>> > >>> Bob > >>> > Their post isn't really about bloat. It's about the discrepancy in > i/o > >>> > bw of memory off-chip and on-chip. > >>> > > >>> > My opinion is that the off-chip memory or hybrid approach is a design > >>> > flaw for a serious router mfg. The flaw is thinking the links' rates > >>> > and the chip memory i/o rates aren't connected when obviously they > >>> > are. Just go fast as possible and let some other device buffer, e.g. > >>> > the end host or the server in the cloud. > >>> > > >>> > Bob > >>> >> https://blog.cerowrt.org/post/juniper/ > >>> >> > >>> >> But they deleted the comment thread. It is interesting, I suppose, > to > >>> >> see how they frame the buffering problems to themselves in their > post: > >>> >> > https://www.linkedin.com/pulse/sizing-router-buffers-small-new-big-sharada-yeluri/ > >>> > _______________________________________________ > >>> > Rpm mailing list > >>> > Rpm@lists.bufferbloat.net > >>> > https://lists.bufferbloat.net/listinfo/rpm > > _______________________________________________ > > Rpm mailing list > > Rpm@lists.bufferbloat.net > > https://lists.bufferbloat.net/listinfo/rpm > _______________________________________________ > Rpm mailing list > Rpm@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/rpm > [-- Attachment #2: Type: text/html, Size: 7720 bytes --] ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Rpm] Almost had a dialog going with juniper... 2023-02-20 17:56 ` Frantisek Borsik @ 2023-02-20 18:27 ` Dave Taht 2023-02-20 19:22 ` rjmcmahon 0 siblings, 1 reply; 12+ messages in thread From: Dave Taht @ 2023-02-20 18:27 UTC (permalink / raw) To: Frantisek Borsik; +Cc: rjmcmahon, Rpm On Mon, Feb 20, 2023 at 9:57 AM Frantisek Borsik via Rpm <rpm@lists.bufferbloat.net> wrote: > >Besides the actual evaporating of those comments that's the saddest thing for me... The article has improved in multiple respects, actually mentioning better packet management earlier than it had, and the overall tone shifted nicely. Frank... in the future, please criticise the ideas, and framing, and not the person. I was, I'll admit, incensed at seeing the comment thread disappear, but I then took a day to write a much better article about the VOQ problem with purchased circuits I have observed many times, and posted it widely. The comment - still preserved on that piece - with that link to that blog entry - I have a nice screenshot of now. :) Stirring up a little controversy along the way towards the truth is fine! We are all in this bloat together, and need to engineer our way out. I really do hope that what I see in so many VOQ -> XGbit SLA configurations (where the delay is additive per voq) is not as common (or as under-observed) as I think it is. Perhaps the scripts and blog I posted will encourage more folk to look at this problem more deeply, as it certainly seems to exist at many ISP->internet interconnects. Maybe good solutions will be posted somewhere on some support site that can be achieved on more hardware available today. https://blog.cerowrt.org/post/juniper/ > All the best, > > Frank > > Frantisek (Frank) Borsik > > >om/in/frantisekborsik >> > Signal, Telegram, WhatsApp: +421919416714 > > iMessage, mobile: +420775230885 > > Skype: casioa5302ca > > frantisek.borsik@gmail.com > > > > On Mon, Feb 20, 2023 at 1:02 AM rjmcmahon via Rpm <rpm@lists.bufferbloat.net> wrote: >> >> Here, look at this. Designed as a WiFi aggregation device. >> >> https://www.arista.com/en/products/750-series >> >> It supplies 60W PoE and claims support for 384 ports. Oh, the max >> distance per PoE AP is 100 meters. >> >> That's insane as a power source and the 100M distance limit is not >> viable. >> >> Our engineering needs to improve a lot. >> >> Bob >> > Cisco's first acquisition was Crescendo. They started with twisted >> > pair and moved to Cat5. At the time, the claim was nobody would rewire >> > corporate offices. But they did and those engineers always had an AC >> > power plug nearby so they never really designed for power/bit over >> > distance. >> > >> > Broadcom purchased Epigram. They started with twisted pair and moved >> > to wireless (CMOS radios.) The engineers found that people really >> > don't want to be tethered to wall jacks. So they had to consider power >> > at all aspects of design. >> > >> > AP engineers have been a bit of a Frankenstein. They have power per AC >> > wall jacks so the blast energy everywhere to sell sq ft. The >> > enterprise AP guys do silly things like PoE. >> > >> > Better is to add CMOS radios everywhere and decrease power, >> > inter-connected by fiber which is the end game in waveguides. Even the >> > data centers are now limited to 4-meter cables when using copper and >> > the energy consumption is through the roof. >> > >> > Bob >> >> On Sun, Feb 19, 2023 at 3:37 PM rjmcmahon <rjmcmahon@rjmcmahon.com> >> >> wrote: >> >>> >> >>> A bit off topic, but the AP/client power asymmetry is another design >> >>> flaw similar to bloat. >> >> >> >> It makes no sense to broadcast at a watt when the device is nearby. I >> >> think this is a huge, and largely unexplored problem. We tried to >> >> tackle it in the minstrel-blues project but didn't get far enough, and >> >> the rate controllers became too proprietary to continue. Some details >> >> here: >> >> >> >> https://github.com/thuehn/Minstrel-Blues >> >> >> >>> >> >>> Not sure why nobody is talking about that. >> >> >> >> Understanding of the inverse square law is rare. The work we did at >> >> google fiber, clearly showed the chromecast stick overdriving nearby >> >> APs. >> >> >> >> https://apenwarr.ca/diary/wifi-data-apenwarr-201602.pdf >> >> >> >> >> >>> https://www.youtube.com/watch?v=Ey5jVUXSJn4 >> >> >> >> Haha. >> >> >> >>> >> >>> Bob >> >>> > Their post isn't really about bloat. It's about the discrepancy in i/o >> >>> > bw of memory off-chip and on-chip. >> >>> > >> >>> > My opinion is that the off-chip memory or hybrid approach is a design >> >>> > flaw for a serious router mfg. The flaw is thinking the links' rates >> >>> > and the chip memory i/o rates aren't connected when obviously they >> >>> > are. Just go fast as possible and let some other device buffer, e.g. >> >>> > the end host or the server in the cloud. >> >>> > >> >>> > Bob >> >>> >> https://blog.cerowrt.org/post/juniper/ >> >>> >> >> >>> >> But they deleted the comment thread. It is interesting, I suppose, to >> >>> >> see how they frame the buffering problems to themselves in their post: >> >>> >> https://www.linkedin.com/pulse/sizing-router-buffers-small-new-big-sharada-yeluri/ >> >>> > _______________________________________________ >> >>> > Rpm mailing list >> >>> > Rpm@lists.bufferbloat.net >> >>> > https://lists.bufferbloat.net/listinfo/rpm >> > _______________________________________________ >> > Rpm mailing list >> > Rpm@lists.bufferbloat.net >> > https://lists.bufferbloat.net/listinfo/rpm >> _______________________________________________ >> Rpm mailing list >> Rpm@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/rpm > > _______________________________________________ > Rpm mailing list > Rpm@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/rpm -- A pithy note on VOQs vs SQM: https://blog.cerowrt.org/post/juniper/ Dave Täht CEO, TekLibre, LLC ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Rpm] Almost had a dialog going with juniper... 2023-02-20 18:27 ` Dave Taht @ 2023-02-20 19:22 ` rjmcmahon 0 siblings, 0 replies; 12+ messages in thread From: rjmcmahon @ 2023-02-20 19:22 UTC (permalink / raw) To: Dave Taht; +Cc: Frantisek Borsik, Rpm Did your tests specifically use a Juniper router? If not, posting those plots on her thread probably only leads to confusion. I think removing them is appropriate. Test results are very much "your mileage will vary" and the conditions of the tests need to be obvious, otherwise I think they muddy the water. Starting with an assumption that every engineering group has bloat is probably ok for a T&M engineer, but anybody making or implying claims against a specific vendor without actual measurements is something I think we all should avoid. We release iperf 2 as open source so each engineering group can measure their systems themselves without any biases ahead of those measurements, and each group can freely inspect the tool too in order to see what it's actually doing. Bob > On Mon, Feb 20, 2023 at 9:57 AM Frantisek Borsik via Rpm > <rpm@lists.bufferbloat.net> wrote: >> >> Besides the actual evaporating of those comments that's the saddest >> thing for me... > > The article has improved in multiple respects, actually mentioning > better packet management earlier than it had, and the overall tone > shifted nicely. > > Frank... in the future, please criticise the ideas, and framing, and > not the person. I was, I'll admit, incensed at seeing the comment > thread disappear, but I then took a day to write a much better article > about the VOQ problem with purchased circuits I have observed many > times, and posted it widely. The comment - still preserved on that > piece - with that link to that blog entry - I have a nice screenshot > of now. :) > > Stirring up a little controversy along the way towards the truth is > fine! We are all in this bloat together, and need to engineer our way > out. > > I really do hope that what I see in so many VOQ -> XGbit SLA > configurations (where the delay is additive per voq) is not as common > (or as under-observed) as I think it is. Perhaps the scripts and blog > I posted will encourage more folk to look at this problem more deeply, > as it certainly seems to exist at many ISP->internet interconnects. > Maybe good solutions will be posted somewhere on some support site > that can be achieved on more hardware available today. > > https://blog.cerowrt.org/post/juniper/ > >> All the best, >> >> Frank > >> >> Frantisek (Frank) Borsik >> >> >> om/in/frantisekborsik >>> >> Signal, Telegram, WhatsApp: +421919416714 >> >> iMessage, mobile: +420775230885 >> >> Skype: casioa5302ca >> >> frantisek.borsik@gmail.com >> >> >> >> On Mon, Feb 20, 2023 at 1:02 AM rjmcmahon via Rpm >> <rpm@lists.bufferbloat.net> wrote: >>> >>> Here, look at this. Designed as a WiFi aggregation device. >>> >>> https://www.arista.com/en/products/750-series >>> >>> It supplies 60W PoE and claims support for 384 ports. Oh, the max >>> distance per PoE AP is 100 meters. >>> >>> That's insane as a power source and the 100M distance limit is not >>> viable. >>> >>> Our engineering needs to improve a lot. >>> >>> Bob >>> > Cisco's first acquisition was Crescendo. They started with twisted >>> > pair and moved to Cat5. At the time, the claim was nobody would rewire >>> > corporate offices. But they did and those engineers always had an AC >>> > power plug nearby so they never really designed for power/bit over >>> > distance. >>> > >>> > Broadcom purchased Epigram. They started with twisted pair and moved >>> > to wireless (CMOS radios.) The engineers found that people really >>> > don't want to be tethered to wall jacks. So they had to consider power >>> > at all aspects of design. >>> > >>> > AP engineers have been a bit of a Frankenstein. They have power per AC >>> > wall jacks so the blast energy everywhere to sell sq ft. The >>> > enterprise AP guys do silly things like PoE. >>> > >>> > Better is to add CMOS radios everywhere and decrease power, >>> > inter-connected by fiber which is the end game in waveguides. Even the >>> > data centers are now limited to 4-meter cables when using copper and >>> > the energy consumption is through the roof. >>> > >>> > Bob >>> >> On Sun, Feb 19, 2023 at 3:37 PM rjmcmahon <rjmcmahon@rjmcmahon.com> >>> >> wrote: >>> >>> >>> >>> A bit off topic, but the AP/client power asymmetry is another design >>> >>> flaw similar to bloat. >>> >> >>> >> It makes no sense to broadcast at a watt when the device is nearby. I >>> >> think this is a huge, and largely unexplored problem. We tried to >>> >> tackle it in the minstrel-blues project but didn't get far enough, and >>> >> the rate controllers became too proprietary to continue. Some details >>> >> here: >>> >> >>> >> https://github.com/thuehn/Minstrel-Blues >>> >> >>> >>> >>> >>> Not sure why nobody is talking about that. >>> >> >>> >> Understanding of the inverse square law is rare. The work we did at >>> >> google fiber, clearly showed the chromecast stick overdriving nearby >>> >> APs. >>> >> >>> >> https://apenwarr.ca/diary/wifi-data-apenwarr-201602.pdf >>> >> >>> >> >>> >>> https://www.youtube.com/watch?v=Ey5jVUXSJn4 >>> >> >>> >> Haha. >>> >> >>> >>> >>> >>> Bob >>> >>> > Their post isn't really about bloat. It's about the discrepancy in i/o >>> >>> > bw of memory off-chip and on-chip. >>> >>> > >>> >>> > My opinion is that the off-chip memory or hybrid approach is a design >>> >>> > flaw for a serious router mfg. The flaw is thinking the links' rates >>> >>> > and the chip memory i/o rates aren't connected when obviously they >>> >>> > are. Just go fast as possible and let some other device buffer, e.g. >>> >>> > the end host or the server in the cloud. >>> >>> > >>> >>> > Bob >>> >>> >> https://blog.cerowrt.org/post/juniper/ >>> >>> >> >>> >>> >> But they deleted the comment thread. It is interesting, I suppose, to >>> >>> >> see how they frame the buffering problems to themselves in their post: >>> >>> >> https://www.linkedin.com/pulse/sizing-router-buffers-small-new-big-sharada-yeluri/ >>> >>> > _______________________________________________ >>> >>> > Rpm mailing list >>> >>> > Rpm@lists.bufferbloat.net >>> >>> > https://lists.bufferbloat.net/listinfo/rpm >>> > _______________________________________________ >>> > Rpm mailing list >>> > Rpm@lists.bufferbloat.net >>> > https://lists.bufferbloat.net/listinfo/rpm >>> _______________________________________________ >>> Rpm mailing list >>> Rpm@lists.bufferbloat.net >>> https://lists.bufferbloat.net/listinfo/rpm >> >> _______________________________________________ >> Rpm mailing list >> Rpm@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/rpm ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Rpm] Almost had a dialog going with juniper... 2023-02-19 23:34 ` rjmcmahon 2023-02-19 23:37 ` rjmcmahon @ 2023-02-19 23:40 ` Dave Taht 2023-02-19 23:44 ` rjmcmahon 1 sibling, 1 reply; 12+ messages in thread From: Dave Taht @ 2023-02-19 23:40 UTC (permalink / raw) To: rjmcmahon; +Cc: Rpm On Sun, Feb 19, 2023 at 3:34 PM rjmcmahon <rjmcmahon@rjmcmahon.com> wrote: > > Their post isn't really about bloat. It's about the discrepancy in i/o > bw of memory off-chip and on-chip. The original comment thread was about how the flow queuing aspect of fq_codel derived algorithms, would leverage on-chip resources better, and about how VOQs do misbehave today. > > My opinion is that the off-chip memory or hybrid approach is a design > flaw for a serious router mfg. I concur. I think we need smarter buffering, not more buffering. Admittedly while the overhead for 10,000 fq_codel'd virtual queues (e.g. 1 million total queue states) without tuning is presently 64M that needs to live in high speed memory for that next indirect lookup... it is possible to trim that down quite a lot. > The flaw is thinking the links' rates and > the chip memory i/o rates aren't connected when obviously they are. Just > go fast as possible and let some other device buffer, e.g. the end host > or the server in the cloud. Juniper will hold onto their big buffers are profitable^H^H^H^H^H^H^H^Hneeded strategy until the bitter end. > > Bob > > https://blog.cerowrt.org/post/juniper/ > > > > But they deleted the comment thread. It is interesting, I suppose, to > > see how they frame the buffering problems to themselves in their post: > > https://www.linkedin.com/pulse/sizing-router-buffers-small-new-big-sharada-yeluri/ -- Surveillance Capitalism? Or DIY? Choose: https://blog.cerowrt.org/post/an_upgrade_in_place/ Dave Täht CEO, TekLibre, LLC ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Rpm] Almost had a dialog going with juniper... 2023-02-19 23:40 ` Dave Taht @ 2023-02-19 23:44 ` rjmcmahon 2023-02-19 23:45 ` Dave Taht 0 siblings, 1 reply; 12+ messages in thread From: rjmcmahon @ 2023-02-19 23:44 UTC (permalink / raw) To: Dave Taht; +Cc: Rpm It's a conflict in design goals. They're trying to sell to customers that don't want data loss in the data centers for things like RDMA messaging and claiming their equipment is universal to all use cases. It's really not. We're TCP end/end guys and packet loss can be a very good signal. Bob > On Sun, Feb 19, 2023 at 3:34 PM rjmcmahon <rjmcmahon@rjmcmahon.com> > wrote: >> >> Their post isn't really about bloat. It's about the discrepancy in i/o >> bw of memory off-chip and on-chip. > > The original comment thread was about how the flow queuing aspect of > fq_codel derived algorithms, would leverage on-chip resources better, > and about how VOQs do misbehave today. > > >> >> My opinion is that the off-chip memory or hybrid approach is a design >> flaw for a serious router mfg. > > I concur. I think we need smarter buffering, not more buffering. > Admittedly while the overhead for > 10,000 fq_codel'd virtual queues (e.g. 1 million total queue states) > without tuning is presently 64M that needs to live in high speed > memory for that next indirect lookup... it is possible to trim that > down quite a lot. > >> The flaw is thinking the links' rates and >> the chip memory i/o rates aren't connected when obviously they are. >> Just >> go fast as possible and let some other device buffer, e.g. the end >> host >> or the server in the cloud. > > Juniper will hold onto their big buffers are > profitable^H^H^H^H^H^H^H^Hneeded strategy until the bitter end. > >> >> Bob >> > https://blog.cerowrt.org/post/juniper/ >> > >> > But they deleted the comment thread. It is interesting, I suppose, to >> > see how they frame the buffering problems to themselves in their post: >> > https://www.linkedin.com/pulse/sizing-router-buffers-small-new-big-sharada-yeluri/ ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Rpm] Almost had a dialog going with juniper... 2023-02-19 23:44 ` rjmcmahon @ 2023-02-19 23:45 ` Dave Taht 0 siblings, 0 replies; 12+ messages in thread From: Dave Taht @ 2023-02-19 23:45 UTC (permalink / raw) To: rjmcmahon; +Cc: Rpm On Sun, Feb 19, 2023 at 3:44 PM rjmcmahon <rjmcmahon@rjmcmahon.com> wrote: > > It's a conflict in design goals. They're trying to sell to customers > that don't want data loss in the data centers for things like RDMA > messaging and claiming their equipment is universal to all use cases. > It's really not. > > We're TCP end/end guys and packet loss can be a very good signal. The test I did in that blog series was with RFC3168 ecn. No loss on the link. > Bob > > On Sun, Feb 19, 2023 at 3:34 PM rjmcmahon <rjmcmahon@rjmcmahon.com> > > wrote: > >> > >> Their post isn't really about bloat. It's about the discrepancy in i/o > >> bw of memory off-chip and on-chip. > > > > The original comment thread was about how the flow queuing aspect of > > fq_codel derived algorithms, would leverage on-chip resources better, > > and about how VOQs do misbehave today. > > > > > >> > >> My opinion is that the off-chip memory or hybrid approach is a design > >> flaw for a serious router mfg. > > > > I concur. I think we need smarter buffering, not more buffering. > > Admittedly while the overhead for > > 10,000 fq_codel'd virtual queues (e.g. 1 million total queue states) > > without tuning is presently 64M that needs to live in high speed > > memory for that next indirect lookup... it is possible to trim that > > down quite a lot. > > > >> The flaw is thinking the links' rates and > >> the chip memory i/o rates aren't connected when obviously they are. > >> Just > >> go fast as possible and let some other device buffer, e.g. the end > >> host > >> or the server in the cloud. > > > > Juniper will hold onto their big buffers are > > profitable^H^H^H^H^H^H^H^Hneeded strategy until the bitter end. > > > >> > >> Bob > >> > https://blog.cerowrt.org/post/juniper/ > >> > > >> > But they deleted the comment thread. It is interesting, I suppose, to > >> > see how they frame the buffering problems to themselves in their post: > >> > https://www.linkedin.com/pulse/sizing-router-buffers-small-new-big-sharada-yeluri/ -- Surveillance Capitalism? Or DIY? Choose: https://blog.cerowrt.org/post/an_upgrade_in_place/ Dave Täht CEO, TekLibre, LLC ^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2023-02-20 19:22 UTC | newest] Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-02-19 23:02 [Rpm] Almost had a dialog going with juniper Dave Taht 2023-02-19 23:34 ` rjmcmahon 2023-02-19 23:37 ` rjmcmahon 2023-02-19 23:44 ` Dave Taht 2023-02-19 23:52 ` rjmcmahon 2023-02-20 0:02 ` rjmcmahon 2023-02-20 17:56 ` Frantisek Borsik 2023-02-20 18:27 ` Dave Taht 2023-02-20 19:22 ` rjmcmahon 2023-02-19 23:40 ` Dave Taht 2023-02-19 23:44 ` rjmcmahon 2023-02-19 23:45 ` Dave Taht
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