Re: [lwip-users] How to force dup ACK

[Kieran Mansley]

On Thu, 2010-04-15 at 18:27 +0800, yueyue papa wrote:
> Is there a suggestion for my current situation?
> 
> I was required to make faster TCP interact.
> 
> But smaller TSS, cause long ACK times, lower performance.

Can you say more about the long ACK times?  This should not be connected
to the segment size.

> Big TSS cause ACK lost, still poor performance.

Fundamentally in a connection with loss you will not be able to get
higher performance: if you send faster you will experience more loss,
and this will degrade the performance to such an extent that you will
get less throughput than you did in the first place.  The right thing to
do when there is loss is to send slower, and this is what lwIP is doing
for you.

If you have a network or application where the loss follows an unusual
pattern that breaks the assumptions made by TCP the best thing is to use
something other than TCP.  e.g. UDP with a tailored loss recovery
algorithm of your own creation on top.

Kieran