Re: [lwip-users] Incorrect ACK number for the TCP Server with PPPoS, NetConn and FreeRTOS

[Joel Cunningham]

On 06/06/2018 09:29 AM, sarp wrote:
> I am implementing a TCP Server with PPPoS where NO_SYS = 0(FreeRTOS).
>
> Everything is OK, one thread feeds ppp and the other opens a netconn socket
> for server and starts listening.
>
> However, when a client is connected, connection is reset because of
> incorrect ACK number with
>
>        the switch case SYN_RCVD of tcp_process() by the function tcp_rst() in
> tcp_in.c
>
> What could be the reason for that?
Are TCP checksums enabled and passing?  First guess is usually data 
corruption in the link layer due to buggy driver

Joel