I recently installed the IP communicator on a laptop with the UC520 system. I have set the TFTP server ip address as the UC520 address which is 192.168.16.1 on the local network.
The phone has identified itself to the UC520, can place and recieve calls as well. My challenge is this, if I call to a local extension (201,202 etc) I can hear the other person, and I can hear my voice coming through my headset as well, but the other person can not hear me.
On calls place to an outside phone number, phone operates correctly, 2 way audio, also, when receiving calls from an outside number, 2 way audio. Only calls to and from local extensions mute my voice.