On Tue, 2006-12-12 at 12:23 +0100, Frédéric BERNON wrote:
> Hi group,
>
> I use lwip 1.2.0 at BSD layer.
>
> If I try to do a TCP connect to an "unplugged" IP device from my lwip
> platform, I block my socket too long. Is there some features or opts.h values
> to use to reduce this timeout?
>
> In tcp.c, I found :
>
> if (pcb->state == SYN_SENT && pcb->nrtx == TCP_SYNMAXRTX) {
> ++pcb_remove;
> LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max SYN retries reached\n"));
> }
>
> So, is the connection timeout equal to TCP_SYNMAXRTX * tcp_slowtmr "period" ?
Not quite. TCP_SYNMAXRTX is the number of times it will retransmit the
SYN before giving up. It doesn't send one every tcp_slowtmr period
though - the gaps between them increase roughly exponentially.
> Is reduce TCP_SYNMAXRTX the good way to reduce the TCP connect timeout?
It's pretty much the only way, but I would question why you need to. I
think it would be better to fix your application to be able to cope with
being blocked, rather than make it dependent on a non-standard TCP
timeout.
Kieran
_______________________________________________
lwip-users mailing list
[email protected]
http://lists.nongnu.org/mailman/listinfo/lwip-users
