ndt-users list created

[Richard Carlson <>]

Hi Maurice;

Hum, from the log it looks like the test successfully completed.  I'm  
going to suspect that this is a bug in the message processing code.   
It has been pointed out that the current code makes the incorrect  
assumption that TCP flows have some kind of message boundaries.  The  
impact is that if a connection is slow, two messages, or 1 message and  
some data could be sent in a single packet.  The result would be that  
the client fails to understand the message, because it expected the  
packet to only contain 1 message.

To help me debug this, could you give me a little more info about your  
setup.  Are you running the Knoppix ISO in your VM or did you build it  
from scratch?  Are you using a bridged or NATed network connection?

I've run the ISO image on my MAC using a bridged network interface  
without any problem.  It is limited to ~fastEthernet rates, but that  
is good enough for my training purposes.

Regards;
Rich

On Mar 12, 2009, at 6:30 PM, Maurice Volaski wrote:

> Hi Rich,
>
> I am once again playing with ndt and once again I'm using a virtual  
> machine via VMWare Fusion on my Mac and the client I'm testing is  
> the Mac itself. When I test it, I'm get a novel error:
>
> S2C throughput test: Received wrong type of the message
>
> Here are details from the server log:
>
> sent 467755008 bytes to client in 10.01 seconds
> Buffer control counters Total = 57099, new data = 0, Draining Queue  
> = 0
> Signal USR2(12) sent to child [7210]
> Signal 12 received by process 7210
> 17:19:25.746404   129.98.90.16:3003 --> 129.98.90.227:59069  
> Collected pkt-pair data max = 48731
> 17:19:25.746404   129.98.90.227:59069 --> 129.98.90.16:3003  
> Collected pkt-pair data max = 55009
> Read '  1 0 3 37 117 2735 48731 6465 16859 7074 54 6 689.81 0 0 0 2  
> 0' from monitor pipe
> Read '  1 0 1 59 590 10274 47482 8449 25941 55009 2215 2044 557.94  
> 33516 33473 85075 0 2224' from monitor pipe
> 373929 kbps inbound
> libweb100: warning: accessing depricated variable AckPktsIn
> libweb100: warning: accessing depricated variable AckPktsOut
> Variable 13 (CwndRestores) not found in KIS
> Variable 22 (MaxCaCwnd) not found in KIS
> Variable 30 (MaxSaCwnd) not found in KIS
> Variable 13 (CwndRestores) not found in KIS
> Variable 22 (MaxCaCwnd) not found in KIS
> Variable 30 (MaxSaCwnd) not found in KIS
> Signal 11 received by process 7210
> Signal 17 received by process 7197
> Protocol error!
> S2C throughput test FAILED!
>
>
> The variables are
> WEB100 Kernel Variables:
> Client: localhost/127.0.0.1
> CurMSS: 1448
> X_Rcvbuf: 33554432
> X_Sndbuf: 33554432
> AckPktsIn: 151705
> AckPktsOut: 0
> BytesRetrans: 78192
> CongAvoid: 83222
> CongestionOverCount: 24
> CongestionSignals: 54
> CountRTT: 149482
> CurCwnd: 99912
> CurRTO: 210
> CurRwinRcvd: 66608
> CurRwinSent: 6144
> CurSsthresh: 33304
> DSACKDups: 0
> DataBytesIn: 0
> DataBytesOut: 457214336
> DataPktsIn: 0
> DataPktsOut: 313953
> DupAcksIn: 2044
> ECNEnabled: 0
> FastRetran: 54
> MaxCwnd: 99912
> MaxMSS: 1448
> MaxRTO: 230
> MaxRTT: 40
> MaxRwinRcvd: 66608
> MaxRwinSent: 6144
> MaxSsthresh: 73848
> MinMSS: 1448
> MinRTO: 210
> MinRTT: 0
> MinRwinRcvd: 0
> MinRwinSent: 5792
> NagleEnabled: 1
> OtherReductions: 100
> PktsIn: 151705
> PktsOut: 313953
> PktsRetrans: 54
> RcvWinScale: 9
> SACKEnabled: 3
> SACKsRcvd: 2212
> SendStall: 0
> SlowStart: 1062
> SampleRTT: 0
> SmoothedRTT: 10
> SndWinScale: 1
> SndLimTimeRwin: 1735876
> SndLimTimeCwnd: 608440
> SndLimTimeSender: 7760984
> SndLimTransRwin: 51874
> SndLimTransCwnd: 19435
> SndLimTransSender: 71053
> SndLimBytesRwin: 308339472
> SndLimBytesCwnd: 114245352
> SndLimBytesSender: 34629512
> SubsequentTimeouts: 0
> SumRTT: 200660
> Timeouts: 0
> TimestampsEnabled: 1
> WinScaleRcvd: 1
> WinScaleSent: 9
> DupAcksOut: 0
> StartTimeUsec: 657840
> Duration: 10105492
> c2sData: 9
> c2sAck: 6
> s2cData: 6
> s2cAck: 9
> half_duplex: 0
> link: 100
> congestion: 0
> bad_cable: 0
> mismatch: 0
> spd: 361.96
> bw: 627.51
> loss: 0.000172000
> avgrtt: 1.34
> waitsec: 0.00
> timesec: 10.00
> order: 0.0135
> rwintime: 0.1718
> sendtime: 0.7680
> cwndtime: 0.0602
> rwin: 0.5082
> swin: 256.0000
> cwin: 0.7623
> rttsec: 0.001342
> Sndbuf: 33554432
> aspd: 0.00000
> CWND-Limited: 2196.12
> minCWNDpeak: 4344
> maxCWNDpeak: 99912
> CWNDpeaks: 54
>
> The theoretical network limit is 627.51 Mbps
> The NDT server has a 16384.0 KByte buffer which limits the  
> throughput to 190760.05 Mbps
> Your PC/Workstation has a 65.0 KByte buffer which limits the  
> throughput to 378.68 Mbps
> The network based flow control limits the throughput to 568.03 Mbps
>
> Client Data reports link is '10 Gig', Client Acks report link is  
> 'OC-12'
> Server Data reports link is 'OC-12', Server Acks report link is '10  
> Gig'
>
> --
>
> Maurice Volaski, 
>
> Computing Support, Rose F. Kennedy Center
> Albert Einstein College of Medicine of Yeshiva University

Richard Carlson

1000 Oakbrook Dr
Ann Arbor, MI  48104

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