This object is used to specify the PPP PAP authentication
password.
The system only utilizes the user name and password when
both cdslVTPppUserName and cdslVTPppPassword are
non-empty strings. To enforce this the following
mechanism is applied.
When both are empty strings, set any single one into
non-empty string would automatically set the other into
the same string. When set any into empty string, the other
object would be set to empty string too automatically.