ndt-users list created

[Rich Carlson <>]

Larry;

I notice the 802.11b/g access point in what appears to be a path from 
the 7206 to the client PC.  Is the client connecting at b (11 Mbps) or g 
(34 Mbps) rates?  Also wifi connections typically achieve about 50% of 
the access links capacity and that depends on may factors.

As background, the NDT system was originally designed to operate in a 
university campus environment.  One of the design considerations was 
that only common network link technologies (10/100/1000 Ethernet, DS3, 
T1, OC-3/12/48/192) would be used.  I also assumed that the use of 
bonded links or subrate links would be limited so they aren't accounted for.

The NDT server uses pkt-pair timings to determine the bottleneck link 
speed and technology.  Since the above assumption was used, individual 
timing measurements were quantized into a link-type bin instead of a 
measured speed bin.  Measurements are rounded up to the next quanta and 
the bin values are printed in the web100srv.log file.

In this case, the 10 Mbps Ethernet message could mean that the Wifi link 
is operating at 802.11b rates.  Another option is to use one of the 
pkt-pair measurement tools to probe the path from your NDT server toward 
the client.  That might tell you something.

Regards;
Rich

On 10/31/2010 1:05 PM, Larry Vaden wrote:
> Hello fellow ndt-users,
>
> This customer is connected to a Cisco 7206 with an upstream
> fiber-based DS3 connection.
>
> How do we go about finding the "10 Mbps Ethernet" short of visiting
> each of the rural pops in the path and running NDT from said pops?
>
> kind regards/ldv
>
> Larry Vaden, CoFounder
> Internet Texoma, Inc.
> Serving Rural Texomaland Since 1995
> We Care About Your Connection!
>
>
> Cisco 7206
> |
> |
> HQ MikroTik distribution router
> |
> |
> wireless backbone link
> |
> |
> DD MikroTik distribution router
> |
> |
> wireless backbone link
> |
> |
> PW MikroTik distribution router
> |
> |
> MikroTik 802.11b/g Access Point
> |
> |
> Client radio (Ubiquiti NanoBridge M2)
> |
> |
> Client Network
> |
> |
> Client PC
>
> Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done
> checking for firewalls . . . . . . . . . . . . . . . . . . .  Done
> running 10s outbound test (client-to-server [C2S]) . . . . . 1.09Mb/s
> running 10s inbound test (server-to-client [S2C]) . . . . . . 7.99Mb/s
> The slowest link in the end-to-end path is a 10 Mbps Ethernet subnet
>   [S2C]: Packet queuing detected
>
>
> WEB100 Enabled Statistics:
> Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done
> checking for firewalls . . . . . . . . . . . . . . . . . . .  Done
> running 10s outbound test (client-to-server [C2S]) . . . . . 1.09Mb/s
> running 10s inbound test (server-to-client [S2C]) . . . . . . 7.99Mb/s
>
>         ------  Client System Details  ------
> OS data: Name = Windows XP, Architecture = x86, Version = 5.1
> Java data: Vendor = Sun Microsystems Inc., Version = 1.5.0_04
>
>         ------  Web100 Detailed Analysis  ------
> 10 Mbps Ethernet link found.
> Link set to Full Duplex mode
> No network congestion discovered.
> Good network cable(s) found
> Normal duplex operation found.
>
> Web100 reports the Round trip time = 240.01 msec; the Packet size = 1460
> Bytes; and
> No packet loss - but packets arrived out-of-order 0.08% of the time
> S2C throughput test: Packet queuing detected: 50.56%
> This connection is receiver limited 40.93% of the time.
> This connection is sender limited 52.17% of the time.
> This connection is network limited 6.9% 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: OFF
> RFC 1323 Window Scaling: ON
>
> Server 'ndt.anl.gov' is probably behind a firewall. [Connection to the
> ephemeral port failed]
> Client is probably behind a firewall. [Connection to the ephemeral port 
> failed]
> Packet size is preserved End-to-End
> Server IP addresses are preserved End-to-End
> Information: Network Address Translation (NAT) box is modifying the
> Client's IP address
>         Server says [aaa.bbb.126.34] but Client says [192.168.1.101]
>
>
> WEB100 Kernel Variables:
> Client: localhost/127.0.0.1
> CurMSS: 1460
> X_Rcvbuf: 16777216
> X_Sndbuf: 16777216
> AckPktsIn: 3759
> AckPktsOut: 0
> BytesRetrans: 0
> CongAvoid: 0
> CongestionOverCount: 0
> CongestionSignals: 0
> CountRTT: 3756
> CurCwnd: 327040
> CurRTO: 452
> CurRwinRcvd: 262144
> CurRwinSent: 5888
> CurSsthresh: -616
> DSACKDups: 0
> DataBytesIn: 0
> DataBytesOut: 11248720
> DataPktsIn: 0
> DataPktsOut: 7678
> DupAcksIn: 3
> ECNEnabled: 0
> FastRetran: 0
> MaxCwnd: 327040
> MaxMSS: 1460
> MaxRTO: 868
> MaxRTT: 488
> MaxRwinRcvd: 262144
> MaxRwinSent: 5888
> MaxSsthresh: 0
> MinMSS: 1460
> MinRTO: 264
> MinRTT: 64
> MinRwinRcvd: 262144
> MinRwinSent: 5840
> NagleEnabled: 1
> OtherReductions: 3
> PktsIn: 3759
> PktsOut: 7678
> PktsRetrans: 0
> RcvWinScale: 8
> SACKEnabled: 3
> SACKsRcvd: 0
> SendStall: 0
> SlowStart: 0
> SampleRTT: 232
> SmoothedRTT: 228
> SndWinScale: 3
> SndLimTimeRwin: 4590486
> SndLimTimeCwnd: 773620
> SndLimTimeSender: 5850347
> SndLimTransRwin: 1786
> SndLimTransCwnd: 81
> SndLimTransSender: 1867
> SndLimBytesRwin: 10372540
> SndLimBytesCwnd: 731760
> SndLimBytesSender: 144420
> SubsequentTimeouts: 0
> SumRTT: 901464
> Timeouts: 0
> TimestampsEnabled: 0
> WinScaleRcvd: 3
> WinScaleSent: 8
> DupAcksOut: 0
> StartTimeUsec: 707808
> Duration: 11216397
> c2sData: 3
> c2sAck: 3
> s2cData: 4
> s2cAck: 3
> half_duplex: 0
> link: 10
> congestion: 0
> bad_cable: 0
> mismatch: 0
> spd: 8.02
> bw: 46.41
> loss: 0.000001000
> avgrtt: 240.01
> waitsec: 0.00
> timesec: 11.00
> order: 0.0008
> rwintime: 0.4093
> sendtime: 0.5217
> cwndtime: 0.0690
> rwin: 2.0000
> swin: 128.0000
> cwin: 2.4951
> rttsec: 0.240006
> Sndbuf: 16777216
> aspd: 0.00000
> CWND-Limited: 325.54
> minCWNDpeak: 265720
> maxCWNDpeak: 327040
> CWNDpeaks: 3
>
> The theoretical network limit is 46.41 Mbps
> The NDT server has a 8192.0 KByte buffer which limits the throughput to
> 533.32 Mbps
> Your PC/Workstation has a 256.0 KByte buffer which limits the throughput to
> 8.33 Mbps
> The network based flow control limits the throughput to 10.39 Mbps
>
> Client Data reports link is 'Ethernet', Client Acks report link is 'Ethernet'
> Server Data reports link is 'T3', Server Acks report link is 'Ethernet'