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Ethernet testing

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Madcow

Electrical
Oct 23, 2002
145
US
I have several embedded designs that need to be validated
and tested. Is there any software or test equipment that
can test the TCP/IP stack and give preformance specs.
ie. connection speed, throughput, response time ect.
Maybe even simulate a high trafic network.
 
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Test equipment exists, but it ain't cheap... I don't have any info at hand, though.


Dan - Owner
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Take a look at "iperf". You can download for free off the web and is for measuring TCP performance.

Peter
 
As MacGyvers indicated, test equipment does exist, but it isn't cheap by any means.

Recently we used a Fluke scopemeter, the Fluke-125 which has some capability of analyzing the physical signals and telling you if they are within spec, what the data rate, jitter, the common mode voltage, etc in addition to having the capability of looking at the waveforms.

Also, a lot of oscilloscopes, especially the modern computer based ones have add on packages, presumably a combination of hardware and software, specifically geared towards communication bus monitoring and analysis.

I appologize for not having more specific recommendations, but I haven't used anything of this sort. From when I was looking for a tool that can analyze RS-485 lines and came upon the Fluke-125 I discovered that there appear to be a lot of products out there geared towards TCP/IP testing so a search should bear some easy fruit. You might want to take a look at BlackBox as I think they had a lot of testers of this nature.
 
Thanks all.
Not being a network person I have little ethernet knowledge.
Do to personel cuts, I've become the resident expert.
I've inherited 4 ethernet connected projects, 2 with PICs,
1 ARM , and 1 TI dsp. Currently all we do is connect them
to a pc and see if the web page comes up. I think I'll
get the TeK and Agilent reps in and demo their stuff.
The iperf looks interesting. So far I get about .5k
transfer then it locks up. Don't know if its my device or
Windows.
Thx again.
 
I think you will be wasting money.(Lots of money!)

I doubt anyone but the router people bother with this.

There are so many other bottle necks in there, that are totally unrelated to the direct raw throughput, that measuring the direct raw throughput, will be like trying to measure the color of the electrons.. It just doesn't matter.

In most cases if the unit can talk at all it has to have the hardware ability to talk period. These are 10Mb/s and 100Mb/s links. You can't talk at 11Mb/s! If you can talk at the two standard rates that's it.

Now about your latency issues. Those are internal to your products. Just how fast can your unit cobble up the requested info and feed it to the media? You find that out buy writing PC code to ask rapidly. Then just sweep the speed until it chokes. This doesn't require any special hardware test gear. It does require some test software writing.

Keith Cress
kcress -
 
Keith, don't forget about Gigabit...

Anything controlled by a PIC is not going to have performance concerns due to the Ethernet... the PIC itself is the bottleneck by orders of magnitude. The ARM is 50/50, depending upon what family you're using, but most will be taxed out by a 100Mb link. A good TI DSP is about the only piece I would think needs testing.

In all of the above cases, I would think a software test suite would be the way to go... I assume you're running some form of OS on the chips (maybe not the PIC), so capturing response times, etc. should be easy-peasy.

Dan - Owner
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I do a lot of ethernet comms with plcs and host systems. And to test properly you need to generate messaging that simulates the maximum level of traffic for the device that you have and make sure that you receive and transmit all messages properly to whatever device that you have designed this for.

example
If you have designed this "device a" and your communicating to "device b". Make sure that you can properly communicate to this device at your maximum rate and throughput without crashing.

I would also run a test through various commercial switches and their various settings since this always effects rate and throughput.

 
The Wireshark software (formerly 'Ethereal') is a great open source package (i.e. free) for monitoring your Ethernet traffic. You simply add a switch into your network and hook in a PC running Ethereal/Wireshark. They may have a few analysis tools built in to check the specs you are looking for. Check it out.
 
wireshark is what I see used that is free ware.

Just do not use a hub when sniffing the port. make sure your on a mirrored port on the switch to get your dump on the ethernet device your trying to test.
 
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