Enable the Web interface by doing the following:
Press [MENU] and then [#]. Next use the up/down arrows select "On" for "Embedded web" and then [SAVE].
(Alternately you can choose Menu -> IP service -> Network Setting -> Embedded web. Next use the up/down arrows select "On" and hit the Menu key one last time to [SAVE].
Get the IP from the phone:
Settings/Menu then Information Display, then down arrow to IP Address
Put the IP Address into the browser of a computer on the same network:
password may also be: voipInfo
Manually configure the device (not auto-provision)
Use these settings, see screenshot for examples:
VOIP Line 1
Phone Number: [lineno]
Line ID: [lineno]_[ext]
Registrar Server Address: 126.96.36.199
Proxy Server Address: 188.8.131.52
Outbound Proxy Server Address: 184.108.40.206
Service Domain: 220.127.116.11