I got inconsistent ipsec null performance results while using t4240rdb board with dpaa ports fman1 and fman2. I have two t4240rdb boards using kernel, dtb, filesystem taken from sdk 1.6.
I use ixia to generate packets. While I am sending packets at a rate of % 100 only in one direction the performance is 400mbps.But while I inject packets at a rate of % 100 in both direction i got 300mbps as an aggregate performance. Why the aggregate performance is not around 2×400 mbps on such a high performance board. I couldnt even reach 400mbps.
After conducting some tests I reached an interesting result. If I decrease the traffic rate near % 60 I got an aggregate 2×420 mbps performance. And I observed the performance is starting to decrease if the packet drops started. I couldn't explain why the performance is dramatically decreasing if I exceed a traffic rate % 60. As if there is a rate control mechanism which limits the total packet throughput. Any help will be appreciated.