Timeout when connecting to a web server thrue a 3G modem

I have now tested the w5200 curcuit for some time.
I have an issue when connection to a WEB server over a 3G modem to send data to a server with http POST.

If I post a message from a normal web client, like safari it works.
But when I try to connect to the WEB server on the same network it fails to connect

If I use an adsl connection it connects both the W5200 and the safari and sends the information correctly.
Some setups

 setIMR(0x07);       // Interrupt registers for W5200

    openTCPSocketOnPort(1, destinationPort);
    connect(1, destinationIP, destinationPort);
    uint8_t temp = getSn_SR(SOCKET_1);
    if( temp == SOCK_ESTABLISHED)

I am using the interrupt and get’s 08, timeout but with the safari browser it works.

I am getting a little desperate here. Can you please send me some hints?

Looking forward to a reply


Hi, jbrandberg.

I think you need to capture packets.

When connection established, 5200 send SYN packet and receive SYN/ACK packet and send ACK packet.

So, check all packet send and receive.

Best regards.