Hi George, That's a mistake on my end. The client is the primary place I found SCHED_RR helpful.
I did commit this in the SVN repository and it's in the tar ball but didn't commit it in the git repository. That's fixed now and they all should be coherent. Bob -----Original Message----- From: George Halpert [mailto:geo...@thesoniccloud.com] Sent: Thursday, September 04, 2014 12:26 AM To: Bob (Robert) McMahon Cc: iperf-users@lists.sourceforge.net; Jon Lederman Subject: Re: [Iperf-users] Difference In Jitter Calculations Between IPerf2 and IPerf3 Hi Bob, Thanks for iperf 2.0.7 - lots of useful changes. I'm curious, why didn't you also use SCHED_RR for the client thread? Thanks, George ----- Original Message ----- From: "Jon Lederman" <jonleder...@gmail.com> To: "Bob (Robert) McMahon" <rmcma...@broadcom.com> Cc: iperf-users@lists.sourceforge.net, "George Halpert" <geo...@thesoniccloud.com> Sent: Tuesday, September 2, 2014 11:47:23 PM Subject: Re: [Iperf-users] Difference In Jitter Calculations Between IPerf2 and IPerf3 Thanks for sending this. Do you have any insights into the reasons for these differences. We will send you our results as well. On Sep 2, 2014, at 5:20 PM, Bob (Robert) McMahon <rmcma...@broadcom.com> wrote: > Ok, I see different values as well. Iperf2 is showing approximately 20 us > jitter while iperf3 is showing ~150 us. This is using a 200Mbs udp stream on > 802.11 AC. > > Bob > From: Bob (Robert) McMahon [mailto:rmcma...@broadcom.com] > Sent: Tuesday, September 02, 2014 1:34 PM > To: Jon Lederman > Cc: iperf-users@lists.sourceforge.net > Subject: Re: [Iperf-users] Difference In Jitter Calculations Between IPerf2 > and IPerf3 > > Don’t know but comments are ignored by the compiler ;) > > Can you share your results? I’d be curious to see the variation and if it > could be related to things like scheduling. > > Also, what os are you using? If you are using linux you may want to set the > processes to use SCHED_RR > > http://www.cyberciti.biz/faq/howto-set-real-time-scheduling-priority-process/ > > I do that in iperf2 > > http://sourceforge.net/projects/iperf2/?source=directory > > Bob > From: Jon Lederman [mailto:jonleder...@gmail.com] > Sent: Tuesday, September 02, 2014 1:29 PM > To: Bob (Robert) McMahon > Cc: iperf-users@lists.sourceforge.net > Subject: Re: [Iperf-users] Difference In Jitter Calculations Between IPerf2 > and IPerf3 > > Thanks. Look forward to your results. Even though I also noticed that the > calculation looks similar on the surface, I did notice a comment in iperf3 to > the effect: > > // XXX: This is NOT the way to calculate jitter > // J = |(R1 - S1) - (R0 - S0)| [/ number of packets, for average] > > Any thoughts why that is in there? The calculation in the code appears to > have come directly out of the RFC 1889/3550. > > Also, I want to clarify that this calculation seems to be average jitter not > instantaneous jitter. > > Thanks. > > -Jon > On Sep 2, 2014, at 4:23 PM, Bob (Robert) McMahon <rmcma...@broadcom.com> > wrote: > > > A quick cursory view of the source suggests the same calculation. Let me run > both on my test rig and see if I get similar results. > > Bob > -----Original Message----- > From: Jon Lederman [mailto:jonleder...@gmail.com] > Sent: Monday, September 01, 2014 5:22 PM > To: iperf-users@lists.sourceforge.net > Subject: [Iperf-users] Difference In Jitter Calculations Between IPerf2 and > IPerf3 > > Hi, > > In measuring jitter using Iperf 2.0.5 and Iperf 3, I have noticed a marked > difference in the calculations up to an order of magnitude. Could you > explain the differences in calculation of jitter between 2.0.5 and 3 and the > accuracy. Which should I rely upon? > > Thanks in advance. > > Jon > ------------------------------------------------------------------------------ > Slashdot TV. > Video for Nerds. Stuff that matters. > http://tv.slashdot.org/ > _______________________________________________ > Iperf-users mailing list > Iperf-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/iperf-users ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ Iperf-users mailing list Iperf-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/iperf-users
