Re: [lwip-users] Delayed Ack causing problems? Where to call tcp_nagle_disable()?

[address@hidden]

You are allowed to disable/enable the nagle algorithm where you like, 
but if you want to do so before sending the first segment, any place of 
these is equally good:

- at initialization time (as you did)
- in the accept callback (for passive connections)
- in the recv-callback before sending (for passive connections)
- in the connected-callback (for active connections)

Simon


FreeRTOS Info wrote:
> I think I have answered my own question.  I put it before these lines,
> and everything is fine now.
>
>    /* Tell TCP that this is the structure we wish to be passed for our
>       callbacks. */
>    tcp_nagle_disable(pcb);//<<<<<<<<<<<<<<<<Added line
>    tcp_arg(pcb, hs);
>
>    /* Set up the various callback functions */
>    tcp_recv(pcb, http_recv);
>    tcp_err(pcb, http_err);
>    tcp_poll(pcb, http_poll, HTTPD_POLL_INTERVAL);
>    tcp_sent(pcb, http_sent);
>
>
> Regards,
> Richard.
>
> + http://www.FreeRTOS.org
> Designed for Microcontrollers.
> More than 7000 downloads per month.
>
>
>
>
> On 06/08/2011 18:12, FreeRTOS Info wrote:
> > Hi,
> >
> > lwIP V1.4.0.
> >
> > I have moved the demo FreeRTOS example from the Windoze simulator onto
> > real hardware in order to check the timing behaviour (which can't really
> > be done in the simulator), and found a timing problem.
> >
> > Using an umodified raw http server from the contrib distribution, I am
> > attempting to retrieve a large jpg file (approx 37K).  The file is
> > retrieved in tact, but very slowly.  I am using a point to point connection.
> >
> > Taking a Wireshark log I see that data is only being sent by lwIP  after
> > an ACK from Windows.  I have attached the log for good measure.
> > 192.168.0.200 is the lwIP end.
> >
> > I have considered three things to fix this.  First I have set
> > TCP_SND_QUEUELEN to (8 * TCP_SND_BUF/TCP_MSS), but that made no
> > difference.  Second I considered the calls to tcp_output() after
> > tcp_write() to make sure data is actually going out immediately, but
> > don't think that is the issue as I'm using an unmodified HTTP server
> > from the contrib distribution.
> >
> > Finally, I want to try disabling the nagle algorithm, and see this can
> > be done by calling tcp_nagle_disable(), but I am unsure where and how to
> > do this?  I don't want to modify the core lwIP code, so assume it should
> > be in the http server code.  It is using the raw API version, so it is
> > not obvious how or where to do to call the macro correctly.
> >
> > I would be grateful for advise or an example.  Thanks.
> >
> >
> > Regards,
> > Richard.
> >
> > + http://www.FreeRTOS.org
> > Designed for Microcontrollers.
> > More than 7000 downloads per month.
> >
> >
> >
> >
> >
> >
> > _______________________________________________
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> > https://lists.nongnu.org/mailman/listinfo/lwip-users
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