Not sure of your setup, but it sounds like a firewall/port conflict where it's not allowing the connection.

Again; not knowing your setup, but the very first thing I do when troubleshooting a voip adapter having issues on a network, is try and isolate the adapter totally. I.e. In your case, just the obi202 and the internet (DSl, Cable modem, etc). If you have the OBI202 behind a network router, experiment with DMZ.

Again; maybe you tried some of this, but not knowing your network setup, I can only suggest based on my networking experience. Take care. Mike.