ndt-users list created

[Richard Carlson <>]

Hi Clayton;

Hum, I just ran a test against your server and it completed without any 
problem.  I did not get any errors, just the report below.  I am surprised 
to see that the connection is sender limited (perhaps it's a CPU issue over 
this network path).

How frequently does this delay occur? (often, frequently, occationally, 
...)  Is there a record in the web100srv.log file?

FYI, after printing the server to client message, the client sits in a read 
loop.  There are a couple of timers that should prevent this loop from 
running on forever.  At the end of the loop a message is written to the 
Java console (do you see this message?).  It then prints the speed on the 
screen and goes on to grab the test results from the server.  I'll need to 
think about this some more and setup my local test network.  It would help 
if you could tell me what the network that failed looked like (is it a 
simple client -- switch -- server or something more complex.

Rich

Comments:

Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done
running 10s outbound test (client to server) . . . . . 3.92Mb/s
running 10s inbound test (server to client) . . . . . . 40.37Mb/s

The slowest link in the end-to-end path is a 100 Mbps Full duplex Fast 
Ethernet subnet

Web100 reports the Round trip time = 34.03 msec; the Packet size = 1380 
Bytes; and
No packet loss - but packets arrived out-of-order 9.48% of the time
This connection is sender limited 98.00% of the time.
This connection is network limited 1.32% of the time.
The theoretical network limit is 309.42 Mbps
The NDT server has a 16384.0 KByte buffer which limits the throughput to 
3761.82 Mbps
Your PC/Workstation has a 257.0 KByte buffer which limits the throughput to 
59.09 Mbps
The network based flow control limits the throughput to 43.93 Mbps
 End Of Email Message

At 04:11 PM 10/13/2005, Clayton Keller wrote:

> Clayton Keller wrote:
> > Richard Carlson wrote:
> >
> > > Hi Clayton;
> > >
> > > This is a bug in the web100srv code.  I forgot to shutdown the control 
> > > socket at the end of the test.  If there are multiple clients then the 
> > > final results are sent in a LIFO manner, so the first client needs to 
> > > wait until all subsequent clients are done before the results are returned.
> > >
> > > I'll issue a patched version soon.  In the mean time you can patch your 
> > > version by hand by adding the line "shutdown(ctlsockfd, SHUT_RDWR);" to 
> > > the web100srv.c file (on line 1126).
> > >
> > > Let me know if that fixes things.
> > >
> > > Rich
> > >
> > >
> > > ---------------------------------------------------------------
> > > Original code:
> > >         if (admin_view == 1) {
> > >             totalcnt = calculate(SumRTT, CountRTT, CongestionSignals, 
> > > PktsOut, DupAcksIn, AckPktsIn,
> > >                         CurrentMSS, SndLimTimeRwin, SndLimTimeCwnd, 
> > > SndLimTimeSender,
> > >                         MaxRwinRcvd, CurrentCwnd, Sndbuf, DataBytesOut, 
> > > mismatch, bad_cable,
> > >                         (int)bwout, (int)bwin, c2sdata, s2cack, 1, debug);
> > >             gen_html((int)bwout, (int)bwin, MinRTT, PktsRetrans, Timeouts,
> > >                         Sndbuf, MaxRwinRcvd, CurrentCwnd, mismatch, 
> > > bad_cable, totalcnt,
> > >                         debug);
> > >         }
> > >
> > >         /* printf("Saved data to log file\n"); */
> > >
> > >         /* exit(0); */
> > > }
> > >
> > > main(argc, argv)
> > >
> > > ----------------------------------------------------------
> > > Modified code
> > >         if (admin_view == 1) {
> > >             totalcnt = calculate(SumRTT, CountRTT, CongestionSignals, 
> > > PktsOut, DupAcksIn, AckPktsIn,
> > >                         CurrentMSS, SndLimTimeRwin, SndLimTimeCwnd, 
> > > SndLimTimeSender,
> > >                         MaxRwinRcvd, CurrentCwnd, Sndbuf, DataBytesOut, 
> > > mismatch, bad_cable,
> > >                         (int)bwout, (int)bwin, c2sdata, s2cack, 1, debug);
> > >             gen_html((int)bwout, (int)bwin, MinRTT, PktsRetrans, Timeouts,
> > >                         Sndbuf, MaxRwinRcvd, CurrentCwnd, mismatch, 
> > > bad_cable, totalcnt,
> > >                         debug);
> > >         }
> > >         shutdown(ctlsockfd, SHUT_RDWR);
> > >         /* printf("Saved data to log file\n"); */
> > >
> > >         /* exit(0); */
> > > }
> > >
> > > main(argc, argv)
> > >
> > >
> > >
> > >
> > > At 01:54 PM 10/12/2005, Clayton Keller wrote:
> > >
> > > > I wanted to address this to the list. I believe there was a similar 
> > > > post a week or so back but I wanted to address this clean.
> > > >
> > > > I currently have web100srv running from /etc/init.d/ndt with the following:
> > > >
> > > > /usr/local/sbin/web100srv -a -m -l /var/log/web100/web100srv.log
> > > >
> > > > The system is running on Fedora Core 4 using a patached 2.6.13 kernel 
> > > > from kernel.org.
> > > >
> > > > The server itself is also sitting behind a PIX firewall.
> > > >
> > > > We have noticed that the Outbound Test will run rather quickly, but 
> > > > when the Inbound, server to client, test is ran it can take upwards of 
> > > > several minutes to complete, many times as much as 4 minutes. There are 
> > > > other times where from the end user's point-of-view it appears the test 
> > > > never completes although you can see results for the test appear in the 
> > > > web100.log file. The test though will continue to sit on the unning 10s 
> > > > inbound test (server to client) . . . . . .
> > > > portion of the test, and many users are beginning to just close out the 
> > > > window.
> > > >
> > > > At this point I am looking for general issues that I can look into and 
> > > > possibly run debug against as far as these tests are concerned.
> > > >
> > > > Clayton Keller
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > >
> > >
> > > Richard A. Carlson                              e-mail: 
> > >
> > > Network Engineer                                phone:  (734) 352-7043
> > > Internet2                                       fax:    (734) 913-4255
> > > 1000 Oakbrook Dr; Suite 300
> > > Ann Arbor,  MI  48104
> > Thanks Richard,
> > I've got a test box I will apply and test to, then look at applying this 
> > to the live box and get some good "in the field testing". I'll let you 
> > know how things go.
> > Clay
> Rich,
>
> It appears that there is still a long delay in the amount of time it takes 
> to complete the Inbound test (several minutes from my own personal 
> attempts). Could we be looking at network issues on my end. At time I do 
> see the following message returned as well:
>
> "Information: Other network traffic is congesting the link"
>
> If you would like to try it out for yourself and see if you can recreate 
> this delay, the test is available at:
>
> http://speedtest.ruraltel.net:7123/
>
> I'd be grateful for any other info I can get, as far as things to look at 
> and run debug against.
>
> Clay

------------------------------------



Richard A. Carlson                              e-mail: 

Network Engineer                                phone:  (734) 352-7043
Internet2                                       fax:    (734) 913-4255
1000 Oakbrook Dr; Suite 300
Ann Arbor,  MI  48104