Re: NetBSD 5.1 TCP performance issue (lots of ACK)

[David Laight <david%l8s.co.uk@localhost>]

On Mon, Oct 24, 2011 at 11:44:10AM +0200, Havard Eidnes wrote:
> 
> > From the stats, it looks like there is loss in the data stream causing
> > SACK.  But I don't see how there would be 237850 pure acks for ~98K data
> > packets; there should be more like 49K.
> 
> I agree, the traditional behaviour is that NetBSD TCP acks every
> second TCP segment.

I've seen Linux stacks defer sending an ACK until the next? kernel
clock tick. This will reduce the ACK count somewhat.
In my case is caused problems with 'slow start' at the other end
(which was also Linux).

        David

-- 
David Laight: david%l8s.co.uk@localhost