Re: [lwip-users] TCP over ethernet

[Kieran Mansley]

On Mon, 2008-02-11 at 21:40 -0800, ramash wrote:
> Hi All,
>       I have been using LWIP 1.2.0 code for Ethernet based transmission; I 
> have
> some doubts regarding Acknowledgement numbers. In the lwip code for TCP we
> can call 
> Lwip_accept->netconn_accept,from here it calls 
>      sys_mbox_fetch(conn->acceptmbox, (void **)&newconn);
> 
> Now the client send an Acknowledgement for this accept packet. Please
> clarify how is this utilized to send data packets?
> 
> Lwip_send->netconn_write,sys_mbox_fetch(conn->mbox, NULL);  
> How the data, sequence number and Acknowledgement number are passed, whether
> they are hard coded or retrieved from the Acknowledgement packet from VC
> client code, If they are retrieved where they are done? 

TCP acknowledgement numbers (more often called sequence numbers) are
internal to the TCP stack, and so they aren't passed through the netconn
or socket APIs.  If you can explain why you need to know about the TCP
acknowledgements in your application perhaps we can help.

Kieran