loss is not as same as I set

[Yee Young]

Hello,

I was running the pantheon to test bbr, setting loss rate with argument --prepand-mm-cmds "mm-loss uplink 0.0001", however in the result pdf, the loss is 0.24% when using a 12mbps trace. If using a 800mbps trace, the loss is 6.73%. I don't know why.

Thank you.

[Francis Y. Yan]

Hi Yee Young,

mm-loss only specifies an i.i.d. random packet loss rate, and there are also congestion-induced losses for packets dropped by the link's queue. I am not sure why the loss turns out to be 0.24% exactly though. Maybe you could pass in an uplink queue of size slightly larger than BDP and see if you can reproduce it.

For the 800 Mbps trace, the reason is probably Mahimahi is not optimized for emulating high-speed links, and you would probably need 32 or 64 vCPUs to actually achieve the throughput. Otherwise, Mahimahi will drop packets when it is unable to catch up with the link speed, increasing the loss rate in your measurement. Hope this helps!

Best,
Francis

--
You received this message because you are subscribed to the Google Groups "Pantheon" group.
To unsubscribe from this group and stop receiving emails from it, send an email to pantheon-stanf...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/pantheon-stanford/70196b1d-c4ac-4a25-8934-317aeca3b9cen%40googlegroups.com.