[Bloat] benefits of ack filtering

[David Lang]

35K PPS of acks is insane, one ack every ms is FAR more than enough to do 'fast 
recovery', and outside the datacenter, one ack per 10ms is probably more than 
enough.

Assuming something that's not too assymetric, thinning out the acks may not make 
any difference in the transfer rate of a single data flow in one direction, but 
if you step back and realize that there may be a need to transfer data in the 
other direction, things change here.

If you have a fully symmetrical link, and are maxing it out in both direction, 
going from 35K PPs of aks competing with data packets and gonig down to 1k PPS 
or 100 PPS (or 10 PPS) would result in a noticable improvement in the flow that 
the acks are competing against.

Stop thinking in terms of single-flow benchmarks and near idle 'upstream' paths.

David Lang