<div dir="ltr">The four part attenuator part would be more interesting to me if it also had a solid state phase shifters. This allows for testing 2x2 MIMO testing per affecting the spatial stream eigen vectors/values. <br><br>Bob<br><br>PS. The price per port isn't competitive. Probably a good idea to survey the market competition.</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Jul 6, 2021 at 6:46 AM Ben Greear <<a href="mailto:greearb@candelatech.com">greearb@candelatech.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hello,<br>
<br>
I am interested to hear wish lists for network testing features. We make test equipment, supporting lots<br>
of wifi stations and a distributed architecture, with built-in udp, tcp, ipv6, http, ... protocols,<br>
and open to creating/improving some of our automated tests.<br>
<br>
I know Dave has some test scripts already, so I'm not necessarily looking to reimplement that,<br>
but more fishing for other/new ideas.<br>
<br>
Thanks,<br>
Ben<br>
<br>
On 7/2/21 4:28 PM, Bob McMahon wrote:<br>
> I think we need the language of math here. It seems like the network power metric, introduced by Kleinrock and Jaffe in the late 70s, is something useful. <br>
> Effective end/end queue depths per Little's law also seems useful. Both are available in iperf 2 from a test perspective. Repurposing test techniques to actual <br>
> traffic could be useful. Hence the question around what exact telemetry is useful to apps making socket write() and read() calls.<br>
> <br>
> Bob<br>
> <br>
> On Fri, Jul 2, 2021 at 10:07 AM Dave Taht <<a href="mailto:dave.taht@gmail.com" target="_blank">dave.taht@gmail.com</a> <mailto:<a href="mailto:dave.taht@gmail.com" target="_blank">dave.taht@gmail.com</a>>> wrote:<br>
> <br>
> In terms of trying to find "Quality" I have tried to encourage folk to<br>
> both read "zen and the art of motorcycle maintenance"[0], and Deming's<br>
> work on "total quality management".<br>
> <br>
> My own slice at this network, computer and lifestyle "issue" is aiming<br>
> for "imperceptible latency" in all things. [1]. There's a lot of<br>
> fallout from that in terms of not just addressing queuing delay, but<br>
> caching, prefetching, and learning more about what a user really needs<br>
> (as opposed to wants) to know via intelligent agents.<br>
> <br>
> [0] If you want to get depressed, read Pirsig's successor to "zen...",<br>
> lila, which is in part about what happens when an engineer hits an<br>
> insoluble problem.<br>
> [1] <a href="https://www.internetsociety.org/events/latency2013/" rel="noreferrer" target="_blank">https://www.internetsociety.org/events/latency2013/</a> <<a href="https://www.internetsociety.org/events/latency2013/" rel="noreferrer" target="_blank">https://www.internetsociety.org/events/latency2013/</a>><br>
> <br>
> <br>
> <br>
> On Thu, Jul 1, 2021 at 6:16 PM David P. Reed <<a href="mailto:dpreed@deepplum.com" target="_blank">dpreed@deepplum.com</a> <mailto:<a href="mailto:dpreed@deepplum.com" target="_blank">dpreed@deepplum.com</a>>> wrote:<br>
> ><br>
> > Well, nice that the folks doing the conference are willing to consider that quality of user experience has little to do with signalling rate at the<br>
> physical layer or throughput of FTP transfers.<br>
> ><br>
> ><br>
> ><br>
> > But honestly, the fact that they call the problem "network quality" suggests that they REALLY, REALLY don't understand the Internet isn't the hardware or<br>
> the routers or even the routing algorithms *to its users*.<br>
> ><br>
> ><br>
> ><br>
> > By ignoring the diversity of applications now and in the future, and the fact that we DON'T KNOW what will be coming up, this conference will likely fall<br>
> into the usual trap that net-heads fall into - optimizing for some imaginary reality that doesn't exist, and in fact will probably never be what users<br>
> actually will do given the chance.<br>
> ><br>
> ><br>
> ><br>
> > I saw this issue in 1976 in the group developing the original Internet protocols - a desire to put *into the network* special tricks to optimize ASR33<br>
> logins to remote computers from terminal concentrators (aka remote login), bulk file transfers between file systems on different time-sharing systems, and<br>
> "sessions" (virtual circuits) that required logins. And then trying to exploit underlying "multicast" by building it into the IP layer, because someone<br>
> thought that TV broadcast would be the dominant application.<br>
> ><br>
> ><br>
> ><br>
> > Frankly, to think of "quality" as something that can be "provided" by "the network" misses the entire point of "end-to-end argument in system design".<br>
> Quality is not a property defined or created by The Network. If you want to talk about Quality, you need to talk about users - all the users at all times,<br>
> now and into the future, and that's something you can't do if you don't bother to include current and future users talking about what they might expect to<br>
> experience that they don't experience.<br>
> ><br>
> ><br>
> ><br>
> > There was much fighting back in 1976 that basically involved "network experts" saying that the network was the place to "solve" such issues as quality,<br>
> so applications could avoid having to solve such issues.<br>
> ><br>
> ><br>
> ><br>
> > What some of us managed to do was to argue that you can't "solve" such issues. All you can do is provide a framework that enables different uses to<br>
> *cooperate* in some way.<br>
> ><br>
> ><br>
> ><br>
> > Which is why the Internet drops packets rather than queueing them, and why diffserv cannot work.<br>
> ><br>
> > (I know the latter is conftroversial, but at the moment, ALL of diffserv attempts to talk about end-to-end applicaiton specific metrics, but never, ever<br>
> explains what the diffserv control points actually do w.r.t. what the IP layer can actually control. So it is meaningless - another violation of the<br>
> so-called end-to-end principle).<br>
> ><br>
> ><br>
> ><br>
> > Networks are about getting packets from here to there, multiplexing the underlying resources. That's it. Quality is a whole different thing. Quality can<br>
> be improved by end-to-end approaches, if the underlying network provides some kind of thing that actually creates a way for end-to-end applications to<br>
> affect queueing and routing decisions, and more importantly getting "telemetry" from the network regarding what is actually going on with the other<br>
> end-to-end users sharing the infrastructure.<br>
> ><br>
> ><br>
> ><br>
> > This conference won't talk about it this way. So don't waste your time.<br>
> ><br>
> ><br>
> ><br>
> ><br>
> ><br>
> ><br>
> ><br>
> > On Wednesday, June 30, 2021 8:12pm, "Dave Taht" <<a href="mailto:dave.taht@gmail.com" target="_blank">dave.taht@gmail.com</a> <mailto:<a href="mailto:dave.taht@gmail.com" target="_blank">dave.taht@gmail.com</a>>> said:<br>
> ><br>
> > > The program committee members are *amazing*. Perhaps, finally, we can<br>
> > > move the bar for the internet's quality metrics past endless, blind<br>
> > > repetitions of speedtest.<br>
> > ><br>
> > > For complete details, please see:<br>
> > > <a href="https://www.iab.org/activities/workshops/network-quality/" rel="noreferrer" target="_blank">https://www.iab.org/activities/workshops/network-quality/</a> <<a href="https://www.iab.org/activities/workshops/network-quality/" rel="noreferrer" target="_blank">https://www.iab.org/activities/workshops/network-quality/</a>><br>
> > ><br>
> > > Submissions Due: Monday 2nd August 2021, midnight AOE (Anywhere On Earth)<br>
> > > Invitations Issued by: Monday 16th August 2021<br>
> > ><br>
> > > Workshop Date: This will be a virtual workshop, spread over three days:<br>
> > ><br>
> > > 1400-1800 UTC Tue 14th September 2021<br>
> > > 1400-1800 UTC Wed 15th September 2021<br>
> > > 1400-1800 UTC Thu 16th September 2021<br>
> > ><br>
> > > Workshop co-chairs: Wes Hardaker, Evgeny Khorov, Omer Shapira<br>
> > ><br>
> > > The Program Committee members:<br>
> > ><br>
> > > Jari Arkko, Olivier Bonaventure, Vint Cerf, Stuart Cheshire, Sam<br>
> > > Crowford, Nick Feamster, Jim Gettys, Toke Hoiland-Jorgensen, Geoff<br>
> > > Huston, Cullen Jennings, Katarzyna Kosek-Szott, Mirja Kuehlewind,<br>
> > > Jason Livingood, Matt Mathias, Randall Meyer, Kathleen Nichols,<br>
> > > Christoph Paasch, Tommy Pauly, Greg White, Keith Winstein.<br>
> > ><br>
> > > Send Submissions to: <a href="mailto:network-quality-workshop-pc@iab.org" target="_blank">network-quality-workshop-pc@iab.org</a> <mailto:<a href="mailto:network-quality-workshop-pc@iab.org" target="_blank">network-quality-workshop-pc@iab.org</a>>.<br>
> > ><br>
> > > Position papers from academia, industry, the open source community and<br>
> > > others that focus on measurements, experiences, observations and<br>
> > > advice for the future are welcome. Papers that reflect experience<br>
> > > based on deployed services are especially welcome. The organizers<br>
> > > understand that specific actions taken by operators are unlikely to be<br>
> > > discussed in detail, so papers discussing general categories of<br>
> > > actions and issues without naming specific technologies, products, or<br>
> > > other players in the ecosystem are expected. Papers should not focus<br>
> > > on specific protocol solutions.<br>
> > ><br>
> > > The workshop will be by invitation only. Those wishing to attend<br>
> > > should submit a position paper to the address above; it may take the<br>
> > > form of an Internet-Draft.<br>
> > ><br>
> > > All inputs submitted and considered relevant will be published on the<br>
> > > workshop website. The organisers will decide whom to invite based on<br>
> > > the submissions received. Sessions will be organized according to<br>
> > > content, and not every accepted submission or invited attendee will<br>
> > > have an opportunity to present as the intent is to foster discussion<br>
> > > and not simply to have a sequence of presentations.<br>
> > ><br>
> > > Position papers from those not planning to attend the virtual sessions<br>
> > > themselves are also encouraged. A workshop report will be published<br>
> > > afterwards.<br>
> > ><br>
> > > Overview:<br>
> > ><br>
> > > "We believe that one of the major factors behind this lack of progress<br>
> > > is the popular perception that throughput is the often sole measure of<br>
> > > the quality of Internet connectivity. With such narrow focus, people<br>
> > > don’t consider questions such as:<br>
> > ><br>
> > > What is the latency under typical working conditions?<br>
> > > How reliable is the connectivity across longer time periods?<br>
> > > Does the network allow the use of a broad range of protocols?<br>
> > > What services can be run by clients of the network?<br>
> > > What kind of IPv4, NAT or IPv6 connectivity is offered, and are there firewalls?<br>
> > > What security mechanisms are available for local services, such as DNS?<br>
> > > To what degree are the privacy, confidentiality, integrity and<br>
> > > authenticity of user communications guarded?<br>
> > ><br>
> > > Improving these aspects of network quality will likely depend on<br>
> > > measurement and exposing metrics to all involved parties, including to<br>
> > > end users in a meaningful way. Such measurements and exposure of the<br>
> > > right metrics will allow service providers and network operators to<br>
> > > focus on the aspects that impacts the users’ experience most and at<br>
> > > the same time empowers users to choose the Internet service that will<br>
> > > give them the best experience."<br>
> > ><br>
> > ><br>
> > > --<br>
> > > Latest Podcast:<br>
> > > <a href="https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/" rel="noreferrer" target="_blank">https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/</a> <<a href="https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/" rel="noreferrer" target="_blank">https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/</a>><br>
> > ><br>
> > > Dave Täht CTO, TekLibre, LLC<br>
> > > _______________________________________________<br>
> > > Cerowrt-devel mailing list<br>
> > > <a href="mailto:Cerowrt-devel@lists.bufferbloat.net" target="_blank">Cerowrt-devel@lists.bufferbloat.net</a> <mailto:<a href="mailto:Cerowrt-devel@lists.bufferbloat.net" target="_blank">Cerowrt-devel@lists.bufferbloat.net</a>><br>
> > > <a href="https://lists.bufferbloat.net/listinfo/cerowrt-devel" rel="noreferrer" target="_blank">https://lists.bufferbloat.net/listinfo/cerowrt-devel</a> <<a href="https://lists.bufferbloat.net/listinfo/cerowrt-devel" rel="noreferrer" target="_blank">https://lists.bufferbloat.net/listinfo/cerowrt-devel</a>><br>
> > ><br>
> <br>
> <br>
> <br>
> --<br>
> Latest Podcast:<br>
> <a href="https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/" rel="noreferrer" target="_blank">https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/</a> <<a href="https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/" rel="noreferrer" target="_blank">https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/</a>><br>
> <br>
> Dave Täht CTO, TekLibre, LLC<br>
> _______________________________________________<br>
> Make-wifi-fast mailing list<br>
> <a href="mailto:Make-wifi-fast@lists.bufferbloat.net" target="_blank">Make-wifi-fast@lists.bufferbloat.net</a> <mailto:<a href="mailto:Make-wifi-fast@lists.bufferbloat.net" target="_blank">Make-wifi-fast@lists.bufferbloat.net</a>><br>
> <a href="https://lists.bufferbloat.net/listinfo/make-wifi-fast" rel="noreferrer" target="_blank">https://lists.bufferbloat.net/listinfo/make-wifi-fast</a> <<a href="https://lists.bufferbloat.net/listinfo/make-wifi-fast" rel="noreferrer" target="_blank">https://lists.bufferbloat.net/listinfo/make-wifi-fast</a>><br>
> <br>
> <br>
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<br>
-- <br>
Ben Greear <<a href="mailto:greearb@candelatech.com" target="_blank">greearb@candelatech.com</a>><br>
Candela Technologies Inc <a href="http://www.candelatech.com" rel="noreferrer" target="_blank">http://www.candelatech.com</a><br>
</blockquote></div>
<br>
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