If your OBi was working on your network, and you simply reconnected it to your network via a different medium, it should continue to work as normal, yes?
Which OBi do you have and what jack are you connecting to your network adapter? Have you tried connecting a PC to that adapter to confirm the connection is healthy? Can your browse to your OBi web interface from a network PC?
You might want to get it working on your network first with a single phone connected directly to the OBi before connecting to your house wiring. One step at a time.
OE