Re: [lwip-users] Connections slowing down after some time

[Steffen Wolfer]

On Fri, 2009-03-06 at 14:21 +0000, Kieran Mansley wrote:
> Looking at the traces there are two problems:
> 
>  1) Sometimes a SYN needs to be retransmitted
>  2) Sometimes data segments are retransmitted only after a very large
> gap
> 
> (...)
>
> The second is rather odd as the time to wait before retransmitting is
> down to the other end.  As an example see frame 60 in the
> slow_reply.pcap trace.  This is a retransmission of frame 59, but it
> waited 6 seconds, which is an unusually long time and isn't really the
> fault of lwIP.  I'd expect it to wait around 200ms.  Are you running a
> normal TCP/IP stack on the other end?

The other end is a desktop computer running Linux (Ubuntu 8.10). Between
the microcontroller board and the desktop pc is a switch. 
Seems like I have to find out why Linux waits such a long time until the
packet.

Steffen