Is there any other logs excluding wai.log that you can use to trace user login/logoff to CA7 Web Client?
Release : 12.1
Other than the wai.log you should see a message like the one below in the ENF log file every time a user logon to CA 7 via the Web Client.
08.53.56 STC69689 S CA78SRVR,PARM='CA7SuserA 007CA310,CA7-userA 007CA310'
userA will be the userid of the user logging on