Re: [lwip-users] LWIP slow web server only with Windows OS request

[address@hidden]

Am 22.09.2021 um 11:38 schrieb Marco Giammarini:
> Dear all,
> in attach you can find new capture.
> The lwip device is: 192.168.1.123 for OSX acquisition, and 192.168.10.123 for 
> windows acquisition.

This clearly looks like a memory/configuration problem in lwIP, as (at
least in the windows trace), the lwIP device is not sending more than
one frame without receiving an ACK. And since windows doesn't expect
this (but wants to send an ACK for every 2nd packet), a timer for
sending the ACK has to expire in windows. This results in 200ms before
the ACK is received.

Normally, the TCP sliding window mechanism should speed things up, but
that doesn't happen here. You need to find out why by checking
lwip_stats and/or enable logging in the tcp modules.

Regards,
Simon

> Anyway, if I put the OSX device into the same network of Win device, the 
> result for OSX device is the same (3/4 seconds to obtain the webpage).
>
> Regards,
> Marco
>
>
>
>
>> Il giorno 20 set 2021, alle ore 12:30, Marco Giammarini 
>> <m.giammarini@gmail.com> ha scritto:
>>
>> Sorry, you are right. This acquisition are wrong. I’ll capture new ones.
>>
>> Regards,
>> Marco
>>
>>> Il giorno 20 set 2021, alle ore 12:16, goldsimon@gmx.de ha scritto:
>>>
>>> Am 20.09.2021 um 11:54 schrieb goldsimon@gmx.de:
>>>> Am 20.09.2021 um 11:23 schrieb Marco Giammarini:
>>>>> In attach you can find two trace captured with Wireshark. One with 
>>>>> Windows, and one with OSX.
>>>>
>>>> There are multiple streams in there. Please explain what we're seeing
>>>> and where you think the problem is.
>>>
>>> BTW, the config you sent before said "TCP_WND = (3*TCP_MSS)", but in the
>>> pcaps, the lwIP device (or what I think it is, you didn't tell) sends a
>>> windows size of 2920 (which is 2 * MSS, not 3 * MSS). Something can't be
>>> right here.
>>>
>>> Regards,
>>> Simon
>>>
>>> _______________________________________________
>>> lwip-users mailing list
>>> lwip-users@nongnu.org
>>> https://lists.nongnu.org/mailman/listinfo/lwip-users
>>
>
>
> _______________________________________________
> lwip-users mailing list
> lwip-users@nongnu.org
> https://lists.nongnu.org/mailman/listinfo/lwip-users
>