Re: [lwip-users] TCP transfer grinds to a halt...

[Sam Jansen]

Eric wrote:

> After about six meg of data transfer my TCP HTTP client grinds to a halt.
> I see some retransmits and dup'd acks before this happens, but they don't seem
> to cause a problem (although I'd understandably like to get rid of the
> retransmits as well).
> My source base is 1.1 updated with the latest commits.
> If you're interested, please look at my attached file.
>  
Well that looks bad. In the trace you attached, it looks like there is a 
whole heap of packet loss going on. To get a good idea of this you can 
try and measure a trace on both the sender and receiver sides. tcptrace 
(www.tcptrace.org) gives you a good graphical view on this.

In that trace, it looks like many of the data packets are being lost 
(then subsequently retransmitted) while as far as I can tell the ack 
packets are fine (there are often duplicate acks).

If you can, take a trace at the other side of the connection and try and 
verify if the packets are indeed being lost.

--
Sam Jansen                                           address@hidden 
Wand Network Research Group             http://www.wand.net.nz/~stj2