From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bobcat.rjmcmahon.com (bobcat.rjmcmahon.com [45.33.58.123]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id A6B3C3B2A4 for ; Sun, 19 Feb 2023 18:52:09 -0500 (EST) Received: from mail.rjmcmahon.com (bobcat.rjmcmahon.com [45.33.58.123]) by bobcat.rjmcmahon.com (Postfix) with ESMTPA id F2C461B258; Sun, 19 Feb 2023 15:52:08 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 bobcat.rjmcmahon.com F2C461B258 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rjmcmahon.com; s=bobcat; t=1676850728; bh=UiR66JlEONNBtvQ1WjNF9X8Q2qO9XGL9+pb+wRBmbrU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=SM0Ttt10RSlENYiiZKEgHz5QT6dfCONIl6cw9wp+VQCBjnQjUmCv4FsnKgmZM/Hsn yDOFYgqqNu5TvSaQphynsd8a0cLkR44GcxvhhK/K9KVw/0NSJbtkngK4olS6G2MRks FHSsNGMPP/Bdz56LglpdenhKl5P5d12DFITHbcvo= MIME-Version: 1.0 Date: Sun, 19 Feb 2023 15:52:08 -0800 From: rjmcmahon To: Dave Taht Cc: Rpm In-Reply-To: References: <26ac4e4e00b1d0f20c816630fafb7e58@rjmcmahon.com> <1209c1b2fb917edc8bf33a73782823bd@rjmcmahon.com> Message-ID: <3f89e35c27c144bbe4b6c8f2128e1557@rjmcmahon.com> X-Sender: rjmcmahon@rjmcmahon.com Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Rpm] Almost had a dialog going with juniper... X-BeenThere: rpm@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: revolutions per minute - a new metric for measuring responsiveness List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 19 Feb 2023 23:52:09 -0000 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 > 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