Increase the size of the number of bytes sent from uint16_t to uint32_t in order to avoid TCP errors with long sessions. For exmple:

int hello_main(int argc, char *argv[])
{
   uint32_t i;
   for(i = 0; i < 65536; i++)
    {
      printf("Hello, World!!\n");
    }

  printf("press any key!!\n");
  if (getchar()=='t')
    return 0;
  else
    return 1;
}

When ran in a Telnet session, the "press any key" is not displayed because the tcp session closed unexpectedly with:

tcp_input: ERROR: conn->sndseq xx, conn->unacked xx"

This is fixed by increasing the width of conn->sent to 32-bits to prevent overflow.

From Rony XLN

net/tcp/tcp.h

@@ -164,7 +164,7 @@ struct tcp_conn_s
   sq_queue_t unacked_q;   /* Write buffering for un-ACKed segments */
   uint16_t   expired;     /* Number segments retransmitted but not yet ACKed,
                            * it can only be updated at TCP_ESTABLISHED state */
-  uint16_t   sent;        /* The number of bytes sent (ACKed and un-ACKed) */
+  uint32_t   sent;        /* The number of bytes sent (ACKed and un-ACKed) */
   uint32_t   isn;         /* Initial sequence number */
 #endif