Zodiac Switch Interface buffer Size and buffering duration

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Zodiac Switch Interface buffer Size and buffering duration
« on: January 14, 2018, 08:17:52 AM »
As a part of my academic work, I am using performance measurement tool to test performance of Zodiac FX switch. The tool generates UDP packets at a fixed rate to only  one port of the switch and checks for packet_in message from control port. But, We don't have controller which can respond to these packet_in messages. I am noticing some drop in the number of packet_in messages when UDP packet generation rate(i.e packets per second ) is increased. I would like to know whether the switch stores the entire packet in its buffer and waits forever for packet_out or other sorts of response from controller? or It would flush the buffer after some time if no response is received from the controller

I appreciate if anyone could come up with an explanation for this?


Paul Zanna

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Re: Zodiac Switch Interface buffer Size and buffering duration
« Reply #1 on: January 22, 2018, 07:08:56 AM »

If you run the Floodlight controller without an application it will packet out every packet in it receives so you may be able to use that for your testing.

As for buffering, there is a small layer 1 hardware buffer in the switch processor (64KB) but the OpenFlow pipeline doesn't have a buffer so there can be overruns under heavy load. All Packet ins are sent with a no buffer flag meaning that the switch sends the entire packet payload to the controller and deletes it's own copy so the switch needs to send that packet payload back with the pack out message or the data is lost.