I am no Sametime guru, but it looks like one of Sametime's logging features could help you out here. Take a look at this page.
Community Login/Logout information1
Each of these three options - Login/Logout by Time, Login/Logout by User, and Failed Logins by Time - contains some or all of the following information about user attempts to log in to a Sametime community:
- User ID - A Lotus Notes User ID (canonical name, such as cn=John Smith, ou=West, o=Acme), a User Name as specified in the Person document of the Sametime directory, or a Distinguished Name from an LDAP directory. Anonymous users are identified by numbers.
- Time - The date and time that a user logged in or logged out.
- Event Type - The type of event being logged: Community Login, Community Logout, or Failed Login.
- IP Address - The IP address of the user's computer.
- Application Type - The type of application from which a user logged in:
- Connect: Sametime Connect for the desktop. Indicates a user is authenticated.
- Connect for browser: Sametime Connect for browsers. Indicates a user is authenticated.
- Web: The Sametime Meeting Room, the Sametime Meeting Center, the Sametime Administration Tool, or an application created with the Sametime Java Software Development Kit.
- Sametime links: An application created with the Sametime Links Software Development Kit.
- DB: An application created with the C++ Software Development Kit.
- Unknown type: Appears when the Application Type cannot be determined.
- Client Version - The user's client version.If "Pre V3.1" or "Post 3.1" appears in this field, then the precise version of the client could not be detected.
- Connectivity - The connectivity method used by the client:
- Direct
- HTTP polling
- HTTP tunneling
- Failure Reason - The reason a login failed.
- Reason - The reason a login failed. Also indicates if a user was able to log out normally.
The administrator can use the "Successful logins" and "Failed logins" options in the Community Server Events to Log settings to record information in the Community Logins/Logouts section of the log.
To access the Community Logins/Logouts section of the Sametime log, select Logging -> Community Logins/Logouts in the Sametime Administration Tool.
I hope this helps you on your quest =)
1Source: https://publib.boulder.ibm.com/infocenter/sametime/v7r5m1/topic/com.ibm.help.sametime.imlu.doc/st_adm_log_loginlogout_r.html