Cisco Cisco Computer Telephony Integration Option 8.5 Guía Del Desarrollador

A duplicate log in attempt is when an agent who is already logged in tries to log 
in a second time using the same ID. Desktop applications must account for such 
a possible situation and have a plan for dealing with it.

You can handle duplicate log in attempts in three ways:

Allow the Duplicate Log In with No Warning

Allow the Duplicate Log In with a Warning

Do not allow a duplicate log in.

You control how duplicate log in attempts are handled in two ways:

By configuring how duplicate log in attempts are to be handled on a global 
basis by creating custom values in the CTI OS Server Registry. By using 
custom values in the CTI OS Server registry to control how duplicate log in 
attempts are handled, and downloading these settings to your desktop 
application as described on page 4-49, you can enable flexibility without 
having to modify your desktop application code.

By implementing code in your desktop application to detect then to handle 
the duplicate log in attempt error according to the custom values in the CTI 
OS Server Registry. You can write code to handle duplicate log in attempts in 
each of the three ways listed above. Then when you must change how such 
attempts are handled, you would simply change the registry settings; you 
would then not need to change the desktop application code.

You can create keys in the CTI OS Server Registry that will instruct desktop 
applications to handle duplicate log in attempts in a specific way.