ndt-users list created

["Joe Freeman" <>]

Greetings-

I have NDT v5.4.12 (as reported in the applet screen) setup on an ubuntu server (2.6.21-web100). S2C appears to run fine, but but my numbers are way low on the C2S side when I test with high speeds.


From one test point (100M connection, 4ms rtt), I only get 19M C2S.

Here's the info I have from the web100 stats...

WEB100 Kernel Variables
Client: localhost/127.0.0.1
CurMSS: 1260
X_Rcvbuf: 262142
X_Sndbuf: 262142
AckPktsIn: 25976
AckPktsOut: 0
BytesRetrans: 6300
CongAvoid: 0
CongestionOverCount: 0
CongestionSignals: 1
CountRTT: 25937
CurCwnd: 100800
CurRTO: 211
CurRwinRcvd: 65520
CurRwinSent: 5840
CurSsthresh: 79380
DSACKDups: 0
DataBytesIn: 0
DataBytesOut: 58701500
DataPktsIn: 0
DataPktsOut: 46221
DupAcksIn: 32
ECNEnabled: 0
FastRetran: 1
MaxCwnd: 100800
MaxMSS: 1260
MaxRTO: 220
MaxRTT: 113
MaxRwinRcvd: 65520
MaxRwinSent: 5840
MaxSsthresh: 126000
MinMSS: 1260
MinRTO: 205
MinRTT: 4
MinRwinRcvd: 0
MinRwinSent: 5840
NagleEnabled: 1
OtherReductions: 1
PktsIn: 25976
PktsOut: 46221
PktsRetrans: 5
RcvWinScale: -1
SACKEnabled: 3
SACKsRcvd: 13
SendStall: 0
SlowStart: 0
SampleRTT: 11
SmoothedRTT: 11
SndWinScale: -1
SndLimTimeRwin: 9936256
SndLimTimeCwnd: 80051
SndLimTimeSender: 59056
SndLimTransRwin: 4
SndLimTransCwnd: 4
SndLimTransSender: 1
SndLimBytesRwin: 58357780
SndLimBytesCwnd: 343720
SndLimBytesSender: 0
SubsequentTimeouts: 0
SumRTT: 288976
Timeouts: 0
TimestampsEnabled: 0
WinScaleRcvd: -1
WinScaleSent: -1
DupAcksOut: 0
StartTimeUsec: 416784
Duration: 10075375
c2sData: 4
c2sAck: 4
s2cData: 9
s2cAck: 9
half_duplex: 0
link: 100
congestion: 0
bad_cable: 0
mismatch: 0
spd: 46.61
bw: 185.50
loss: 0.000021635
avgrtt: 11.14
waitsec: 0.00
timesec: 10.00
order: 0.0012
rwintime: 0.9862
sendtime: 0.0059
cwndtime: 0.0079
rwin: 0.4999
swin: 2.0000
cwin: 0.7690
rttsec: 0.011141
Sndbuf: 262142
aspd: 0.00000
CWND-Limited: 1506.36

The theoretical network limit is 185.5 Mbps
The NDT server has a 127.0 KByte buffer which limits the throughput to 179.51 Mbps
Your PC/Workstation has a 63.0 KByte buffer which limits the throughput to 44.87 Mbps
The network based flow control limits the throughput to 69.02 Mbps
 Client Data reports link is 'T3', Client Acks report link is 'T3'
Server Data reports link is '10 Gig', Server Acks report link is '10 Gig'

The server link is actually 100M Ethernet for the moment it'll go to 1G when I get the correct sfp for my router.

One thing I can't figure out is that NDT always seems to report a server buffer of 127KB, even on much slower connections. If autotuning is used (it is enabled.. I double checked), I'd expect that number to change as well.. at least in variation with the rtt between the client and server.

Any thoughts as to where I should be looking?

Thanks-
Joe