perfSONAR User Q&A and Other Discussion

[Alan Whinery <>]

Interesting. A lot of intrigue there -- SACKs, out-of-orders, etc.

Could you do one more with

web100clt -ll -n <target>
?

I should have suggested multiple L but it's been a while since I had looked at the invocation spec. This will include a dump of all the web100 variables, like:

CurMSS: 1448
X_Rcvbuf: 87380
X_Sndbuf: 542520
AckPktsIn: 42069
AckPktsOut: 0
BytesRetrans: 97016
CongAvoid: 40313
CongestionOverCount: 77
CongestionSignals: 16
CountRTT: 40601
CurCwnd: 115840
CurRTO: 209
CurRwinRcvd: 397312
CurRwinSent: 18432
CurSsthresh: 60816
DSACKDups: 0
DataBytesIn: 0
DataBytesOut: 117766944
DataPktsIn: 0
DataPktsOut: 81047
DupAcksIn: 1469
ECNEnabled: 0
FastRetran: 16
MaxCwnd: 198376
MaxMSS: 1448
MaxRTO: 214
MaxRTT: 16
MaxRwinRcvd: 397312
MaxRwinSent: 18432
MaxSsthresh: 92672
MinMSS: 1448
MinRTO: 201
MinRTT: 1
MinRwinRcvd: 15360
MinRwinSent: 17896
NagleEnabled: 1
OtherReductions: 29
PktsIn: 42069
PktsOut: 81047
PktsRetrans: 67
RcvWinScale: 10
SACKEnabled: 3
SACKsRcvd: 1705
SendStall: 0
SlowStart: 142
SampleRTT: 9
SmoothedRTT: 9
SndWinScale: 10
SndLimTimeRwin: 16984
SndLimTimeCwnd: 1737301
SndLimTimeSender: 8634977
SndLimTransRwin: 11
SndLimTransCwnd: 6393
SndLimTransSender: 6400
SndLimBytesRwin: 253616
SndLimBytesCwnd: 69329000
SndLimBytesSender: 48184328
SubsequentTimeouts: 0
SumRTT: 316680
Timeouts: 0
TimestampsEnabled: 1
WinScaleRcvd: 10
WinScaleSent: 10
DupAcksOut: 0
StartTimeUsec: 299246
Duration: 10389356
c2sData: 5
c2sAck: 5
s2cData: 5
s2cAck: 5
half_duplex: 0
link: 100
congestion: 1
bad_cable: 0
mismatch: 0
spd: 90.68
bw: 100.81
loss: 0.000197416
avgrtt: 7.80
waitsec: 0.00
timesec: 10.00
order: 0.0349
rwintime: 0.0016
sendtime: 0.8311
cwndtime: 0.1672
rwin: 3.0312
swin: 4.1391
cwin: 1.5135
rttsec: 0.007800
Sndbuf: 542520
aspd: 0.00000
CWND-Limited: 23959.00
minCWNDpeak: 52128
maxCWNDpeak: 179552
CWNDpeaks: 30

On May 5, 2014 6:07:56 AM HST, "Koch, Brian" wrote:

sys-its-70vlk81 ~]# web100clt -l -n 129.120.255.107
Testing network path for configuration and performance problems  --  Using IPv4 address
Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done
checking for firewalls . . . . . . . . . . . . . . . . . . .  Failed to connect: No route to host
No sockets could be created that match requirements.
Done
running 10s outbound test (client to server) . . . . .  1049.25 Mb/s
running 10s inbound test (server to client) . . . . . . 1132.42 Mb/s
sending meta information to server . . . . . Done
The slowest link in the end-to-end path is a 2.4 Gbps OC-48 subnet
Information: Other network traffic is congesting the link
Server '129.120.255.107' is probably behind a firewall. [Connection to the ephemeral port failed]
Client is probably behind a firewall. [Connection to the ephemeral port failed]

        ------  Web100 Detailed Analysis  ------

Web100 reports the Round trip time = 9.06 msec;the Packet size = 1448 Bytes; and
There were 1781 packets retransmitted, 6271 duplicate acks received, and 10121 SACK blocks received
Packets arrived out-of-order 1.36% of the time.
This connection is sender limited 96.83% of the time.
This connection is network limited 3.08% of the time.

    Web100 reports TCP negotiated the optional Performance Settings to:
RFC 2018 Selective Acknowledgment: ON
RFC 896 Nagle Algorithm: ON
RFC 3168 Explicit Congestion Notification: OFF
RFC 1323 Time Stamping: ON
RFC 1323 Window Scaling: ON; Scaling Factors - Server=10, Client=10
The theoretical network limit is 311.75 Mbps
The NDT server has a 5971 KByte buffer which limits the throughput to 5149.34 Mbps
Your PC/Workstation has a 3770 KByte buffer which limits the throughput to 3251.25 Mbps
The network based flow control limits the throughput to 1884.12 Mbps

Client Data reports link is '  8', Client Acks report link is '  8'
Server Data reports link is '  9', Server Acks report link is '  9'
Packet size is preserved End-to-End
Information: Network Address Translation (NAT) box is modifying the Server's IP address
        Server says [::ffff:129.120.255.107] but Client says [ 129.120.255.107]
Information: Network Address Translation (NAT) box is modifying the Client's IP address
        Server says [::ffff:10.3.254.5] but Client says [ 10.3.254.5]

-----Original Message-----
From:  [] On Behalf Of Alan Whinery
Sent: Friday, May 02, 2014 4:10 PM
To: 
Subject: Re: [perfsonar-user] bwctl speed questions

Brian  T. - Yes, he said there was a firewall.

Brian Koch,

If NDT is enabled as a service on the target host, can you do

web100clt -l -n <targethost>

and send the results?

Note: if you are sanitizing, the IP target's name or IP appears once in the output.



On 5/2/2014 11:04 AM, Brian Tierney wrote:
 With 909 retransmits, you will never get much about 1Gbps.

 How "full" is that path? Is there a firewall on the path? Also look at 
 errors on all your router / switch interfaces.
 There may be a dirty fiber.




 On Fri, May 2, 2014 at 1:52 PM, Koch, Brian  wrote:
 Latency shows ~0.7ms with 0% loss.

 -----Original Message-----
 From: Brian Tierney []
 Sent: Friday, May 02, 2014 3:35 PM
 Cc: Koch, Brian; 
 Subject: Re: [perfsonar-user] bwctl speed questions

 Brian: What latency is the path you are testing? Does owamp show any packet loss on that path?

 Try doing a test with iperf3, which will give you TCP retransmit  count.

 bwctl -c hostname -I iperf3 -i1 -fm -x -t20




 On Fri, May 2, 2014 at 7:47 AM, Aaron Brown  wrote:
 Hey Brian,

 Unfortunately, there’s not a way to do multiple streams currently. The idea was to show how single stream performance looked since any network can be made to look good with enough streams :) The next version of the Toolkit should include the ability to configure number of streams, however.

 Cheers,
 Aaron

 On May 2, 2014, at 10:04 AM,  wrote:

 Is there a way to run multiple data streams? I'm not sure why the 
 data path is fully tested.
 Connections:
 Perfsonar --> core router (10G)
 core router --> firewall (10G) (fw throughput = 2G) firewall --> 
 outside WAN router (10G) outside WAN router --> perfsonar (10G)

 Theoretically, I should be seeing close to 2Gbps on my bwctl 
 graphs, but graphs are barely showing over 1Gbps.

 Are there some settings I need to tweak? I'm a little new to this.


 --
 Brian Tierney, http://www.es.net/tierney

 Energy Sciences Network (ESnet), Berkeley National Lab

 http://fasterdata.es.net