On the wired side, I understand goodput as the bitrate of delivered data payload [source]. This excludes all encapsulation, headers, and retransmits.
On the Aruba wireless side, my Mobility Master dashboard defines goodput as:
...the ratio of the total bytes transmitted or received in the network to the total air time required for transmitting or receiving the bytes. The air time includes the retransmission time taken for both successful and dropped frames.
Suppose 1000 frames of 1500 bytes each are transmitted in the network as follows:
50% of frames are transmitted successfully at MCS index 11 at 108 Mbps.
25% of the frames were dropped in the 1st attempt at 108 Mbps but were successfully transmitted using MCS index 3 at 54 Mbps in the second attempt.
The remaining 25% are dropped in both the attempts.
Then the effective rate is calculated as: The total bits transmitted / the total air time. In this example: (500 * 1500 + 250 * 1500) * 8 / (total air time for 50% frames + total air time for 25 % frames retransmitted + total air time for 25% dropped frames) = 40.5 Mbps.
Which, if either, are correct?
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