Newbie: *65 says unknown connection

I recently installed trixbox and setup a SIP extension as follows:

Extension number: 2102
Extension display name: Test
password: Test

Then, I installed x-lite softphone in my ubuntu box to test the said SIP,

Default connection:
Enables; yes
display name: Test
Username: 2102
Authorization number: 2102
Password: Test
SIP Proxy: trixbox_IP (we are in the same subnet), say, 192.168.1.14
Domain/Realm: default. Should it be the network, as in 192.168.1.0?

It seems to connect, indicating I am logged in. When I dial *65, instead of it telling what is my extension it is says the extension is unknown. Did I miss anything?