There are TCP/IP tuning things you may need to do to get around the bandwidth*delay product.
When a TCP/IP session starts up, one of the things which is exchanged is the maximum 'receive window' and 'transmit window'. This is effectively the maximum number of bits which can be in-flight at a given moment. The relevant formula here is windowsize=bandwidth * delay. For whatever reason my windows 10 machine seems to like to default to a window size of 65536, or 524288 bits. Dividing this by for instance a delay (latency) of 5ms, you get just over 104Mb/s maximum. Reducing the delay by half doubles the maximum. Doubling the window size also doubles the maximum. Windows is supposed to auto-scale the window size. In theory it is supposed to be able to adjust this all the way up to 16MB based on the default scaling value it uses. (it probably can even be tweaked further). This would result in around 3.4GB of throughput at 5ms delay. I don't know how well this actually works though.... Of course there are two parts to this - *both* ends need to be configured to use the larger window sizes. I have found that often the server-end of these tests end up with a horribly small transmit window which tends to be the bottleneck. On Wed, Sep 20, 2017 at 2:31 PM, Chuck McCown <[email protected]> wrote: > Yeah, that is kinda what I am running in to. There has to be a way around > it. I posted this problem to ookla too. Hopefully they will respond. > > *From:* Al Rachide > *Sent:* Wednesday, September 20, 2017 2:28 PM > *To:* [email protected] > *Subject:* Re: [AFMUG] Speed Tests > > We did a speed test on a full GIG DIA fiber line. It took THREE computers > simultaneously, two with I5s and one with an I7 processor. All 3 had > gigabit internet cards. We did indeed get a totwl throughput of 997mbit > down and 1003mbit up. But that was the combined total of all 3 computers > running the speed test at the same time. We think the reality is that any > one computer, no matter how powerful, can actually send or receive 1000mbit > speed. Al > > On Wed, Sep 20, 2017 at 3:38 PM, <[email protected]> wrote: > >> Send Af mailing list submissions to >> [email protected] >> >> To subscribe or unsubscribe via the World Wide Web, visit >> http://afmug.com/mailman/listinfo/af >> or, via email, send a message with subject or body 'help' to >> [email protected] >> >> You can reach the person managing the list at >> [email protected] >> >> When replying, please edit your Subject line so it is more specific >> than "Re: Contents of Af digest..." >> >> >> Today's Topics: >> >> 1. Re: Hold on Gino.... (Steve Jones) >> 2. Speedtests (Chuck McCown) >> 3. Re: Speedtests (Jesse DuPont) >> >> >> ---------------------------------------------------------------------- >> >> Message: 1 >> Date: Wed, 20 Sep 2017 14:22:53 -0500 >> From: Steve Jones <[email protected]> >> To: "[email protected]" <[email protected]> >> Subject: Re: [AFMUG] Hold on Gino.... >> Message-ID: >> <CAGOa4nPnp2-CwYrHFsecuF9jn7tid_fOwbg-in7fLb6FRPiYBA@mail. >> gmail.com> >> Content-Type: text/plain; charset="utf-8" >> >> their power is like 80 or more percent out >> >> On Wed, Sep 20, 2017 at 1:43 PM, Zach Underwood <[email protected]> >> wrote: >> >> > Also looks like his backbone is still online >> > >> > https://stat.ripe.net/14979#tabId=routing >> > >> > On Wed, Sep 20, 2017 at 2:39 PM, Zach Underwood <[email protected]> >> > wrote: >> > >> >> More than half of the prefix from PR are offline >> >> https://stat.ripe.net/PR#tabId=routing >> >> >> >> On Wed, Sep 20, 2017 at 2:28 PM, SmarterBroadband <[email protected]> >> wrote: >> >> >> >>> Maria must have be giving you hell. >> >>> >> >>> No power on the island!!! >> >>> >> >>> Hold on and Good luck. >> >>> >> >> >> >> >> >> >> >> -- >> >> Zach Underwood (RHCE,RHCSA,RHCT,UACA) >> >> My website <http://zachunderwood.me> >> >> advance-networking.com >> >> >> > >> > >> > >> > -- >> > Zach Underwood (RHCE,RHCSA,RHCT,UACA) >> > My website <http://zachunderwood.me> >> > advance-networking.com >> > >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: <http://afmug.com/pipermail/af/attachments/20170920/96558efd >> /attachment-0001.html> >> >> ------------------------------ >> >> Message: 2 >> Date: Wed, 20 Sep 2017 13:34:36 -0600 >> From: "Chuck McCown" <[email protected]> >> To: <[email protected]> >> Subject: [AFMUG] Speedtests >> Message-ID: <B6646750F342408BAD1B98628F2B839F@ChuckMcCownPC> >> Content-Type: text/plain; charset="iso-8859-1" >> >> Hard to find an app or appliance that will reliably show a customer the >> speed they are getting when it is above 100 Mbps. We have increasingly >> more 250, 500 and 1G customers and when they complain that speed test shows >> a lower number I need something to prove them wrong. An average laptop >> does not cut it. >> >> We have installed our own speedtest server with the ookla recommended >> hardware etc. But it takes a pretty good computer that actually show a >> gig. Ditto iperf. Be nice if there was some kind of handheld device that >> could do this. There are all kinds of hand held computers designed to >> roll your own piece of test or control gear. Just not sure what is >> important. >> >> CPU speed >> Memory size >> PHY circuit >> Memory type >> >> I guess I should ask this question of ookla... >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: <http://afmug.com/pipermail/af/attachments/20170920/0a9b1b90 >> /attachment-0001.html> >> >> ------------------------------ >> >> Message: 3 >> Date: Wed, 20 Sep 2017 13:38:23 -0600 >> From: Jesse DuPont <[email protected]> >> To: [email protected] >> Subject: Re: [AFMUG] Speedtests >> Message-ID: <[email protected]> >> Content-Type: text/plain; charset="us-ascii" >> >> An HTML attachment was scrubbed... >> URL: <http://afmug.com/pipermail/af/attachments/20170920/c79c66ee >> /attachment.html> >> -------------- next part -------------- >> A non-text attachment was scrubbed... >> Name: celeritynetworks-GIF.gif >> Type: image/gif >> Size: 1869 bytes >> Desc: not available >> URL: <http://afmug.com/pipermail/af/attachments/20170920/c79c66ee >> /attachment.gif> >> -------------- next part -------------- >> A non-text attachment was scrubbed... >> Name: Screen Shot 2017-09-20 at 9.48.58 AM.png >> Type: image/png >> Size: 110022 bytes >> Desc: not available >> URL: <http://afmug.com/pipermail/af/attachments/20170920/c79c66ee >> /attachment.png> >> >> ------------------------------ >> >> Subject: Digest Footer >> >> _______________________________________________ >> Af mailing list >> [email protected] >> http://afmug.com/mailman/listinfo/af >> >> >> ------------------------------ >> >> End of Af Digest, Vol 37, Issue 321 >> *********************************** >> > > > > -- > Al Rachide > Pink Hill, NC > -- *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 [email protected] | http://www.packetflux.com <http://www.linkedin.com/in/fwchristian> <http://facebook.com/packetflux> <http://twitter.com/@packetflux>
