[ovs-discuss] Decrease in delay with increase in input traffic rate

[Uzzam Javed]

Thanks for the reply. The Y-axis shows the number of times a delay value on
X-axis occurs.


The router which I am using is Mikrotik RouterBoard 750GL, and I have
erased the factory installed firmware. As a replacement, I have installed
for OpenWRT ‘Chaos Calmer’ with Open vSwitch 2.1.2 (OvS) package. I have
configured OVS by adding a bridge, ports to it and controller through
‘ovs-vsctl’ command. I am using Distributed Internet Traffic Generator for
generating traffic.



I have repeated the experiments on GENI using OVS as an OpenFlow switch
configured as explained in the this tutorial
http://groups.geni.net/geni/wiki/GENIExperimenter/Tutorials/OpenFlowOVS/DesignSetup
. The same set of experiments are repeated on Mininet using OVS switch. The
results of all the experiments are same that as the rate increases overall
delay decreases.

I am using OVS in all the three platforms.


Any specific reason for decrease in delay? Does it relate to how OVS is
processing the flows and can I verify it somehow?



Uzzam



On Sat, Dec 19, 2015 at 4:26 AM, Justin Pettit <jpettit at ovn.org> wrote:

> I'm not sure I understand the Y-axis.  Regardless, it sounds like you're
> not using a hardware OpenFlow switch, and not OVS, so you're probably
> better off asking them.  I'd guess it has to do with the flows being
> cached, but it's complete speculation, since it's going to depend on how
> they implemented their OpenFlow stack.
>
> --Justin
>
>
> > On Dec 17, 2015, at 10:16 AM, Uzzam Javed <13mseeujaved at seecs.edu.pk>
> wrote:
> >
> > Hi everyone, I am doing some experiments on a commercial router enabled
> with OVS. I have connected two hosts to two ports of the router and have
> added both ways flow entries through ‘ofctl’ command. I am generating round
> trip traffic through a traffic generator at a constant rate. The total
> number packets are kept constant to 10,000 packets. When I increase the
> rate the overall delay decreases. The attached picture shows the density
> plots of the 3 experiments having rate 10, 100 and 1000 packets/s input
> traffic rate, respectively.
> >
> >
> >
> > What is the reason for these results that why delay decreases with
> increase in input traffic rate?
> >
> >
> >
> > Thanks,
> >
> > Uzzam
> >
> > <rate_incr.jpg>_______________________________________________
> > discuss mailing list
> > discuss at openvswitch.org
> > http://openvswitch.org/mailman/listinfo/discuss
>
>
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