connect the product to a PBX phone system or terminal adapter, you
must change the product's line type. PBX (Private Branch Exchange)
is used in office environments where an external access code such
as “9” must be dialed to call an outside line. The default Line
Type setting is PSTN (Public Switched Telephone Network), which is
a standard home phone line.
setting can be locked by an administrator. If you can't access or
change this setting, contact your administrator for