[En-Nut-Discussion] TCP/HTTP problem

Wojciech Niziński niziak at spox.org
Fri Jul 12 09:13:35 CEST 2013

In article <24E383FC1C8DCF48ACAB94CA2BAE7A29281BB774
@exchbox01.ccsi.local>, you say...
> Hi all,
> We made a product with AT91_SAM7X256 and Nut/OS 4.8.7. Recently we found a 
> problem with accessing the webpage via Internet. We can replicate the 
> issue with one IP router (we use port forwarding from port 80 to 80). The 
> webpage becomes inaccessible for a while but then returns to the working 
> condition after about a minute. In the inaccessible state, the webpage is 
> not reachable via both the LAN side &the WAN side but pings work. We watch 
> the messages with Wireshark
during the test. We see TCP RST sent by our product (Nut/OS) during the 
inaccessible state.
> Did anyone see this problem before? Is there a solution for this problem?

Probably all server threads are busy (very popular case when you are
accessing your embedded device remotely from slow networks, i.e. from mobile

Please try with low socket timeouts, i.e. 5 seconds or less:

        #define HTTP_SOCKET_TIMEOUT     5000
        u_long tmo = HTTP_SOCKET_TIMEOUT;
        NutTcpAccept    (sock, 80);
        NutTcpSetSockOpt(sock, SO_RCVTIMEO, &tmo, sizeof(tmo));
        NutTcpSetSockOpt(sock, SO_SNDTIMEO, &tmo, sizeof(tmo));

Best Regards
Wojciech Niziński 

More information about the En-Nut-Discussion mailing list