ndt-users list created

[Byron Hicks <>]

I'm reasonably certain that I have a clean path.

Both boxes are running NDT, and I get the same result in both directions:

Houston:

running 10s outbound test (client to server) . . . . .  9123.91 Mb/s
running 10s inbound test (server to client) . . . . . . 1434.11 Mb/s

Dallas:

running 10s outbound test (client to server) . . . . .  8953.05 Mb/s
running 10s inbound test (server to client) . . . . . . 1440.18 Mb/s

If it were a traffic loss issue, I would expect that the
outbound/inbound numbers would flip, with the lower number being on the
"leg" of the duplex path that had the traffic loss.

But I'm not.  Client to Server is 9Gb/s and Server to Client is 1.4Gb/s,
regardless of which NDT server I'm testing from/to.  And considering
that I'm getting 9Gb/s on a 10Gb/s link using iperf in both directions,
I'm pretty sure packet loss is a not a factor. 

How do I interpret the following:

Information [S2C]: Packet queuing detected: 80.16% (remote buffers)

Where is the packet queuing happening? 


On 05/15/2013 01:37 PM, Brian Tierney wrote:
> Another possibility is that I've seen cases where, on a path with packet 
> loss, different clients seem to trigger different loss patterns.
>
> For example, here is on a clean path:
>
>
>> web100clt -n ps-lax-10g.cenic.net -b 33554432
> running 10s outbound test (client to server) . . . . .  2321.11 Mb/s
> running 10s inbound test (server to client) . . . . . . 2802.95 Mb/s
>
> vs bwctl:
>
>> bwctl -c ps-lax-10g.cenic.net -fm
> bwctl: Using tool: iperf
> [ 14] local 137.164.28.105 port 5001 connected with 198.129.254.98 port 5001
> [ ID] Interval       Transfer     Bandwidth
> [ 14]  0.0-10.0 sec  2984 MBytes  2496 Mbits/sec
>
> performance is similar.
>
> ----------
>
> And here are the results for a path with packet loss:
>
>> web100clt -n ps-lax-10g.cenic.net -b 33554432
> running 10s outbound test (client to server) . . . . .  18.06 Mb/s
> running 10s inbound test (server to client) . . . . . . 2492.69 Mb/s
>
>> bwctl -c ps-lax-10g.cenic.net -fm
> [ 14] local 137.164.28.105 port 5001 connected with 198.129.254.150 port 
> 5001
> [ ID] Interval       Transfer     Bandwidth
> [ 14]  0.0-10.3 sec   552 MBytes   450 Mbits/sec
>
> Here iperf does 30x better than NDT (and btw, nuttcp results agree with the 
> NDT results in this case)
>
> My guess is that different tools have different burst characteristics, and 
> these trigger different amounts of packet loss.
>

-- 
Byron Hicks
Lonestar Education and Research Network
office: 972-883-4645
google: 972-746-2549
aim/skype: byronhicks