Re: [lwip-users] LWIP and sliding window

[Kieran Mansley]

On Wed, 2009-09-30 at 10:57 -0700, Yann Suisini wrote:
> ello ,
> 
> 
> Currently I'm using the KEIL TCPnet stack on my system (ARM LPC23xx) .
> It's working well on a LAN with low latency (about 650KB/s on the embedded
> ftp server with SD card access).
> But I can only send frames one at one , waiting for an ACK before I can send
> another frame .
> So with high ping about 300ms on a intercontinental connection , I  get this
> :
> 
> 1500 bytes sent
> 300ms before ack
> 1500 bytes sent
> 300ms for ACK...
> 
> So the max I get in this case is about 3.5 KB/s  !!!
> 
> I would replace this stack by Lwip but I would know if I cand send more than
> one frames before waiting for an ACK
> in order to optimize use of the bandwith. So , does Lwip manges tcp
> windowing ?

Yes lwIP can do this, but I find it very hard to believe that there is
any TCP stack that doesn't do TCP windowing.  Are you sure the KEIL
TCPnet stack can't do this?  You may just need to change the way it is
configured.

Kieran