We have a ewon 2005CD firmware 11_2s2 that use a proxy port to forward port 502 Wan to port 502 Lan. After approx. 1h the port disconnects. After a few seconds it is possible to reconnect again until the next 1h. Without Ewon between the client and server application everything works fine. We already set parameter MaxCallDu to zero without result. There are no errors or warnings present in the logfiles. Any ideas?