Can I setup the VOIP so that when I dial into the FXO port it does not give a second dial tone, but simply places the call to my SIP-Server, which will then do further processing.

Yes, you can setup the VOIP so that when it receives a call on the FXO port, it automatically calls the phone number in the outbound phone book. You must use firmware version 6.04, 4.04 or newer.

- Go to Configuration ->Voice / Fax

- Enable Auto Call

- Enter the destination pattern in the phone number