Grandstream Networks GXP 1620 User Manual page 6

4. Hover cursor over [Accounts]. Select [Account 1] and click [General Settings].
SIP Server and Outbound Proxy Login: Enter
Account Name, SIP User ID, Authenticate ID: Enter
Authenticate Password: Enter
changed, please enter the new one.
Voicemail User ID: Enter 999.
Once done, click [Save and
Set on both accounts. *Note that they must have different registered UID's
Login
Registered Password
Apply]
Server.
Unique ID (10 characters).
(sent thru mail). *If password was