Re: SV: [lwip-users] TCP payload is doubled

[address@hidden]

David Shmelzer wrote:
> I'm still confused as to why the the window size is decreasing in the
> first place in 1.3.1 and not in 1.3.0. Isn't that causing the silly
> window syndrome? The lwIP server is processing the packets immediately
> via the callback API so the window should not be decreasing.
>   
That seems like a bug in the silly window avoidance mechanism: at the 
time your application calls tcp_recved() to release the windows space of 
the newly received data, the stack doesn't know it hasn't sent out the 
decreased window yet. You're right that it shouldn't shrink the window 
in this case.

I assume you did call tcp_recved() inside your tcp-rcv-callback() and 
not after that callback has returned, of course.

I filed a bug on savannah, please feel free to add further information 
there.

Simon