Testing LFNs (Wrapup)

Kaegler, Mike KaeglerM at tessco.com
Wed May 6 12:20:49 CDT 2009

Thanks to everyone who responded on and off-list!
It seems evident that I didn't have a complete understanding of the iperf
switches which alter buffer sizes.

Several people made a few neat points, which I'll quickly summarize:

* In iperf, -P will allow one to run multiple tcp tests at once.
* IOS has a built-in tester... ttcp. http://tinyurl.com/6fp75j
* For suggestions on changing the kernel buffer sizes:
*  . http://www.29west.com/docs/THPM/ (section 8)
*  . http://fasterdata.es.net/
* Linux.com has a related writeup: http://www.linux.com/feature/144532

Finally, "past performance does not indicate future results" applies here.
44mbit will not necessarily go clean just because 6 did.

Thanks for the tips,

On 5/6/09 11:10 AM, "Michael Kaegler" <kaeglerm at tessco.com> wrote:

> I have a new T3 thats 65msec long. I'd usually be using iperf to test new
> links, but at 65msec, even at the maximum window size, I can only get
> 6-8mbit through. No combination of options I've been able to find has gotten
> me more than 6mbit through this link. Should I just shotgun 9 copies of it?
> Are there better ways to test these links? Can one verify this link with
> just a pair of 7200s and linux machines on either side? Or is this something
> one really needs "real" test hardware for? If 6mbit go through clean, is
> there a real chance 44 will not?
> TIA,
> -mKaegler

Michael Kaegler, TESSCO Technologies: Engineering, 410 229 1295
Your wireless success, nothing less. http://www.tessco.com/

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