perfSONAR User Q&A and Other Discussion

[Jeff White <>]

So when doing a bandwidth test PS will obviously try its hardest to fill 
the pipe as much as it can.  Assuming the PS host can fill a link to 
that connection's full capacity and no limitations (traffic shaper, ACL, 
firewall, etc.) are in place, how does that affect other traffic using 
that link?

Take this example:

* PS node A in building A connected to core router A at 10Gb/s

* Building A's core router connected to building B's core router at 10Gb/s

* PS node B in building B connected to core router B at 10Gb/s

* 2Gb/s of normal traffic is flowing between core router A and B

* The PS nodes begin a throughput test between A and B

What happens?

The routers are not looking at QOS or whatever so they wouldn't know 
that the PS test is less important traffic and therefore should be 
dropped when capacity is reached.  So wouldn't the router just start 
dropping packets somewhat randomly, including packets of non-test traffic?

Are any users of PS putting limitations in place to prevent this?  If 
so, what and how?

--
Jeff White - GNU+Linux Systems Administrator
University of Pittsburgh - CSSD