How do I maximize (and monitor) TCP traffic?

[Casey]

I am trying to generate ethernet (TCP/IP) traffic to test some networking equipment. I put Data Server.vi program on one computer, and Data Client.vi on another.

-Running both VIs sends data across the ethernet connection: perfect.
-Increasing the value in the data server.vi control called 'number of points' also increases the traffic: perfect.
-However, above a certain value for 'number of points', the traffic decreases. The most traffic I was able to generate was 14 Mps. I want at least 50 Mps, if not more. How do I increase the traffic generated across the ethernet interface?
-I would also like to be able to monitor the traffic bandwidth and display it on the front panel. How do I do that?
-Finally, I would
eventually like to be able to do this all from one computer. It would send data through some route, and measure how fast it comes back. I know this involves somehow defeating or faking out the loopback prevention on ethernet, and telling the data to take a certain route and "come back". Does anyone have any thoughts here?

Thanks,
Casey

[Dennis_Knutson]

I've never found a satisfactory software only solution. I use a SmartBits from Spirent Communications for network testing.

[Casey]

I suspected as much for the network testing. However, there is quite a bit of value in just being able to generate a lot of traffic, and even more value in determining what the speed of the traffic is programatically.

Do you have any idea on what's limiting my traffic to 14 Mps (the max rate should be 100 Mps full duplex, so it's probably not the hardware) and how to get Labview to read the speed of the transfer?

Thanks,
Casey

[Ben]

First let me second Dennis's suggestion.

I suspect there may be three factors that could be limiting the speed.

1) PC_Memory >>> NIC interface.

2) Ethernet itself.

3) Units

If possible try using a cross-over cable between two machines and see if you can push it up over 14 Mps (?).

THis could address the >>> NIC issue.

Next, when last I looked at the internals of ethernet adapters, they watched their transmision to see if it wnet out correctly. If a collisioon was detected, the hardware would enter a random wait and then try again. This limited the top end of ethernet agregate performance to something less than 40% of the physical layers spec (in this regard token ring blew-away ethernet).

Last thought;
you did not mention if you are counting
bits or bytes. Ethernet (and other comm speeds) are generally spec'd as BITS not bytes.

If this is the case, then you are doing pretty good.

If none of the above applies, please forgive the distraction.

Ben

[Ben]

Another thought;

I have never been able to get more that 20 MegaBits per second performance out of PC to PC file transfers over my 100 Mbs LAN at home. I did not try knocking all the other nodes off before trying this so there may be other factors invloved in this observation.

Please keep us posted if you do manage to get this going the way you want.

Ben

[Vishi Anand]

We use a software called Chariot (expensive) here at work in addition to
SmartBits. Writing your own code in LV won't help you get the data rates
that you want. Look at some freeware software apps that let you do it, they
will probably need a linux box.


vishi

"Dennis Knutson" wrote in message
news:50650000000500000014E60000-1042324653000@exchange.ni.com...
> I've never found a satisfactory software only solution. I use a
> SmartBits from Spirent
> Communications for network testing.