1 | initial version |
Delayed ACK is adding another ~50ms delay per lost packet as each lost packet is retransmitted individually and therefor the ACK to each retransmission is sent a the DelayedACK timout (as there is not a second packet and the client does not have data to send).
So each lost packet takes ~168ms (iRTT) + ~50ms (DelayedAckTimeout) = ~218ms to be retransmitted. Multiplying by the about of packets lost (which seems to be happening in bursts) which is quite high.
If your loadbalancer supports it, you can enable SACK on the client-side and keep it disabled on the server side if your servers do not support it.