From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 04E813CB35 for ; Sat, 21 Aug 2021 07:01:27 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1629543678; bh=pdyhZSRAlMnp/Guo+nT+UU9lrG75NM44bjM1+9GDF1s=; h=X-UI-Sender-Class:Subject:From:In-Reply-To:Date:Cc:References:To; b=Hc75NR4jlMnf6ORi3Z9IXgzC+qETl9HEXqO5a68Slys1YS9CNI5dYPiD9QgrMErI0 NAWWVgmF2kU6waiqK/us7jOVsLbOHRjZbOPmM7A8/kuTI5zv53zMTv4dwiLJDPD4um ooNf43w3UABgKPpbtaMGosLbKYops3jPNRqO02Co= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [192.168.42.229] ([77.6.100.215]) by mail.gmx.net (mrgmx005 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MAOJV-1mBeVh05wB-00Bpfz; Sat, 21 Aug 2021 13:01:18 +0200 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.21\)) From: Sebastian Moeller In-Reply-To: Date: Sat, 21 Aug 2021 13:01:17 +0200 Cc: bloat@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: <3D6CA092-D8DB-412D-9E01-50D9AD0A71D4@gmx.de> References: <20210815133922.GA18118@unix-ag.uni-kl.de> <20210819071734.GA3936@unix-ag.uni-kl.de> <80e0a336-06e4-c6b6-a01b-f849296086a6@indexexchange.com> <6C2AF637474AE2E1E8AC10A0@[192.168.1.16]> <9933fd82-c57b-5cf0-d898-066d42f90040@indexexchange.com> To: Kenneth Porter X-Mailer: Apple Mail (2.3445.104.21) X-Provags-ID: V03:K1:G5qprFqoT7+zGnkiRKY3gnvlMG4NzWDlfdhBKGpkz8KNUcEr6In VjI1zmq9p/d8/qk9m7OKAmALA1UsnZyHi5QUPltJgWc0AQDaaxXYGEQYXk3YE4Fe1sz5EX3 vd2JOjqc7m4ru8lPx4Xwrcf9DuAJ+Grw6ROl7oGlD8tr5WvcHp5vTLgwCxz92ONJzp07bdg CBJEBgeJjCi46XvMZHClg== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:851IZ0mbQ5A=:fBN2bdMH5Qg5ruzPa4vEIP NwR7GzCf0X0RkbiwO75jrVv8mGbWp+97OMcCuKjuy9BuFMERPBMx4mE5Hm71OWqt+7mnPB5TW pD2HN55DubjGOwQ0yNJF6tqFHpxteIiL552vrV0Y0PY1NC5PXioUu8q3D8x4l7/unv4eq/o8y kM5H2K+ITbrG/a4HerxPEZ2SYCz2Po1dZ5tDyH+JXU3wKFOw3upmWN6MY7yWdY63YPi0HrHnK yQRfhhc2KC2TGdWdXwFZJQvvzwSB2YhwHCb/nz/+5o08oSFMN0H7wQzjHybCF38Ct00iqTInw ZJv56ViUXnprSV7mG0CP8Bqnd6evaXP8hLsXcWYZrer7ULCWOj63dW2o/9SGWYpAjFWnSN6xA SGqtyaU/GeZAuJ5Y0jpgEyxl4buOZrOF2mpxlkj5/rAV9A2GCiQbRc2EYP57caa8tlCQ0ET8Q dttD4ahgGj8/PPiwY/pRXvPUj0fBtuPA33qQqhYOI0DlbXinfvUuvT+fxzINq252GlnnGvmPj rMZhJsP/3mn1DeWHLmfw4X0IW1LocbTnz6le6t6yXTqv30WlvNMDHb+M0EJL694w/KLXwvmbY K//7qByag2out+cfhLzbMde1F+mjlXbMnT7RmR7U4lw5PsnmoaH1S4AhgvfBDnvrTs25w30uc qbeBiCwuoSLCoaEOv768Bp1rpKuckcPY2tH4pz34OAvJO79Mlc5s7hLQ4VqwCdZDmo8PXqhiF RyOOqgmgMaio3kbz8a0zkWteRIAHuh/+KnFAiPj3yotUMCvim6n7hjmEdjV2URrUy6LuyIFkP jnydIrjAQHjh3xoQESGzV74kezhKwpt02o93bUIKybd7ZN6+1U8aUBxixC+qctdQhCm4dCmYX JTjs5lhbNr0hNo+lyOdaqc/xmb6SLY0zNTapSlrtFxIAzwJ4/iXQG3oTcdVhqkxwg+Z+rSy/r wTTKEbBvIDaLX4buKwwDDVAT98LQrdWcgAefRlzyH07AXpwhwLNyzqSX2tsIWUwwIioXeGje2 8MZYJxUxI763RA+aUTWEDV8RPFS8X1ZlOZme+87PdpOfZot0I82NjLY8V5PkURxUk3xy0m4Gh HBbvJuamK4Eel8vclasQGaATTicTdr3w2Bk Subject: Re: [Bloat] Sidebar re illustrating quality (was: New Version Notification for draft-cpaasch-ippm-responsiveness-00.txt) X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 21 Aug 2021 11:01:28 -0000 So here is my take, to assess the usefulness of an internet access link (any link probably, = but being an end user myself, I want to limit myself to where I have = first hand experience) there are a number of easier/harder to get = numbers: 1) access rate: easy to measure (at least as HTTPS/TCP/IP goodput, gross = rate of the bottleneck link is considerable harder to deduce) 2) latency to the end-point under test: also easy to measure (simply by = running an ICMP probe stream before and during a speedtest; also some = more enlightened speedtests already report both RTTs) IMHO that actually should be a tuple of=20 latency without load RTT(unloaded) , and latency under = saturating conditions RTT(saturated) =3D> if both numbers exist, the difference RTT(saturated) - = RTT(unloaded) =3D Latency under load increase (LULI ;)) can be = calculated which is a proxy of the level of latency degradation a = user can expect as a function of load. 3) latency variation/jitter: also reasonable easy to measure with tools = like MTR. Quite a number of use-cases work well with moderately high, = but static RTTs but deteriorate quickly if the latency becomes too = variable (Some access technologies, like WiFi or DOCSIS are prone to = introduce jitter, as is XDSL when ITU G.998.4 G.INP retransmissions = enter the picture) 4) packet loss: relatively hard to measure, but some tools like iperf = seem to report retransmissions,=20 5) packet re-ordering: hard to measure (IIUC) if severe enough this will = manifest as apparent packet loss/replay attack =09 RPM. IMHO is nice additional way to address 2) above, but personally, I = am less interested in how many hypothetical transactions I could perform = per second as compared to how long each takes, as the latter still = allows me to make reasonable guesses of completion time if I issue = transactions in parallel, and the LULI measure can be reasonably = compared with what ever latency budget a given task has. Any attempt as trying to display all these five in one consistent plot = is IMHO challenging, because such a plot should use a scale of equal = severity for all its axis, otherwise it becomes really hard to parse as = an aggregate, no? Regards =20 > On Aug 21, 2021, at 03:22, Kenneth Porter = wrote: >=20 > On 8/19/2021 6:58 PM, Dave Collier-Brown wrote: >> Look at the barrel link, in that case: I'll send you a sketch = off-list=20 >=20 > Ok, the sketch is of a spoked wheel with 3 spokes, for throughput, = latency, and RPM, and the spoke for throughput is much longer. The = circle represents the spoke of smallest radius, indicating the worst = rating of the service. The ISP will try to sell based on the longest = spoke to make itself look better than the actual user experience. >=20 > It's like taking the barrel illustration and "exploding" the barrel so = its staves lie flat, radiating from the base. In that case, the shortest = stave is the worst rating. >=20 >=20 > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat