From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ej1-x62e.google.com (mail-ej1-x62e.google.com [IPv6:2a00:1450:4864:20::62e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id A7EB73B29D for ; Wed, 21 Oct 2020 13:54:30 -0400 (EDT) Received: by mail-ej1-x62e.google.com with SMTP id dt13so4465256ejb.12 for ; Wed, 21 Oct 2020 10:54:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=mime-version:from:date:message-id:subject:to; bh=kbpXOJeGuGASU7uwr8wPNpuQbao2o5Ad+7K+8+nr4WI=; b=YLNEy8d71jTO4aGRgnecGM5SWRsV45qI1bVxOPyx9fw7XB5z+Fbk8XWketZVvLlWWV 7Q++5WgvmSxDyIZGUPctbmny1IrfJ0VzG+rCGRCgAoEghs5/fE2nXMi9/lAuoIdPNQRC emtFdCOM5LHfTE6ZmWr9MehDhTkKrteZt0Epo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=kbpXOJeGuGASU7uwr8wPNpuQbao2o5Ad+7K+8+nr4WI=; b=ojb3RfxXXIHquR9pLfiWgh9ZBOgVgI896IORXsY5uBrOtbGG6Cl/9GOhEC9t1vBflj Qx6S0cASmoA+121PM+G+zpUrgZjKnERoyPucer+F/uCAN5l8AXVGQc/zOsfTcuZgCCGt m/gLFeB0eIVXcHDrgWDT+mUs8dkEvN876lC58FOcnrgyedp2+T5E9FmbLnVxcqKJZoAf RufayK0RJtXJeoRbnt2a8GzaHVXgue82M8jzutMHu2a7uTfz9FzDH2zZj6Z1mspsrwb7 7amkgocfaPKXICiT6bHw/3rybsv3d1N3CHkC4GFKTireiDIdRqipspBd7IkiM4g7QzfS ToPg== X-Gm-Message-State: AOAM530NFbRhS5IdIjohmD/Gc9PTloxANF5tIDg5CtEhj8WtK0Nlzz3Z sdnBwtLB3o6NqNfzLfJ1uGlEOFYXWLdnkjVlPcM5Caha9Bpf8Q== X-Google-Smtp-Source: ABdhPJwtjumqxkbB/SdFj6UrIhZxd3uZaYUV9v6PwX/qFrd4FZMDhdL7AmrNKV6FyHXSpvuYkIcqQy+FWNUYcZPZVnQ= X-Received: by 2002:a17:906:2b5b:: with SMTP id b27mr4724119ejg.400.1603302869355; Wed, 21 Oct 2020 10:54:29 -0700 (PDT) MIME-Version: 1.0 From: Bob McMahon Date: Wed, 21 Oct 2020 10:54:18 -0700 Message-ID: To: Make-Wifi-fast Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-256; boundary="00000000000004b0c305b2320ada" Subject: [Make-wifi-fast] pressure for better clocks X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Oct 2020 17:54:30 -0000 --00000000000004b0c305b2320ada Content-Type: multipart/alternative; boundary="000000000000ff2c1605b23209c9" --000000000000ff2c1605b23209c9 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi All, Iperf 2.0.14 provides end/end latency measurements but requires sync'ed clocks. The lack of attention to end/end latency is a major deficit to the networking industry and impairs user experience. Ping isn't the real deal either. I find one of the many problems with the tech industry is that cheap mass market stuff proliferates. An example of this is the oscillators used for time keeping which run things like CPUs. There are many ways to get better time without spending too much. The GPS atomic clocks are basically available for free over most of the planet. Cellular clocks, synced to GPS, are available indoors. Here is a good article: https://www.pcworld.com/article/2891892/why-computers-still-struggle-to-tel= l-the-time.html *But computer makers often use inexpensive crystals costing only a few cents each, which can compromise accuracy. =E2=80=9CIf you buy server-class hardware, you will get cheap crystal, and time will wander if you don=E2=80= =99t do something about it,=E2=80=9D Neville-Neil said.The average crystal ends up = being about as accurate as a mechanical watch* Bob McMahon --000000000000ff2c1605b23209c9 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi All,

Iperf 2.0.14 provides end/end latency meas= urements but requires sync'ed clocks. The lack of attention to end/end = latency is a major deficit to the networking industry and impairs user expe= rience. Ping isn't the real deal either.

I find one of the many = problems with the tech industry is that cheap mass market stuff proliferate= s.=C2=A0 An example of this is the oscillators used for time keeping which = run things like CPUs.=C2=A0 There are many ways to get better time without = spending too much. The GPS atomic=C2=A0clocks are basically available for f= ree over most of the planet. Cellular=C2=A0clocks, synced to GPS, are avail= able indoors.

Here is a good article:

https://www.pcworld.com/article/2891892/why-computer= s-still-struggle-to-tell-the-time.html

But computer makers of= ten use inexpensive crystals costing only a few cents each, which can compr= omise accuracy. =E2=80=9CIf you buy server-class hardware, you will get che= ap crystal, and time will wander if you don=E2=80=99t do something about it= ,=E2=80=9D Neville-Neil said.

The average crystal ends up being abou= t as accurate as a mechanical watch

Bob = McMahon
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