ndt-users list created

[Richard Carlson <>]

Hi Phil;

What version of Linux are you using?  Have you tuned the stack 
(/proc/sys/net/ipv4/tcp_*mem)?  Also, look at the "More Details" window and 
let me know what CurCwnd, CurRwinRcvd, Duration, and Sndbuf values are.

Off the top of my head, either the Linux stack is untuned and the server is 
limiting the throughput, or the NDT has a bug and the test is running 
longer than it should, (and skewing the results).

Rich
At 07:55 PM 9/12/2005, Phil Reese wrote:
> All,
>
> From notes from several users and my own experience, I've found that my 
> NDT server seems to greatly underrate inbound (server to client) 
> bandwidth. However, from my campus machine, the speeds (inbound and 
> outbound) seem about right and consistent with tests just after I 
> deployed the new server.
>
> As a data point, I've run the NDT test and gotten results and then run a 
> DSL reports speed test.  The DSL report site usually gives me the speed I 
> believe I have at my home via cable modem, while NDT reports drastically 
> different results.
>
> For example:
>
> NDT
> running 10s outbound test (client to server) . . . . . 757Kb/s
> running 10s inbound test (server to client) . . . . . . 2.78Mb/s
>
> DSL Reports
> Upload    768K
> Download  7.34M
>
> Also, NDT provides an extra line suggesting that setting my received 
> buffer to a different value would give better results.  Originally, I was 
> getting results via NDT very similar to the DSL numbers and no additional 
> commentary on the receiver buffer size.
>
> Any ideas what might have happened or is happening with my server?
>
> I've rebooted and stopped and restarted the services several times. I'm 
> using 5.3.3e version of the frontend.
>
> Any help would be appreciated!
>
> Phil Reese
> Stanford

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Richard A. Carlson                              e-mail: 

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