Hi Guys,
This may be a bit off-topic, but I need the help off the best firewall experts I can get ;-)
I want a process-computer, somewhere in the field, to communicate with a central computer. They use a dedicated protocol, now packed in TCP or UDP messages.
The process computer is connected via a GPRS-modem with build in IP stack. The only thing I can do is setting up an the connection (TCP or UDP) an get my data via the RS-232 port. Because off cost issues I want to communicate only is necessary. The initiative of this communication is sometimes with the central, sometimes with remote device. The initiative for the connection is always with the remote evice, because of the dynamic IP addresses for GPRS.
Now my problem. At the central site a hardware firewall is used. This drops the connection at certain time. Both for UDP and TCP. Is there any way to keep this connection open? Or is this normal firewall behavior without any solution. Is it because this kind of communication differs from normal web serving behavior?
In short, ant tip and trick is welcome! I'm counting you experts... :-)