CAS uses jTDS JDBC Driver for connection with SQL server
The connection parameters are defined in \config\repository.properties file, in this URL format for jTDS:
To configure connection timeout you need to add socketTimeout=X property to this URL:
socketTimeout (default - 0)
The amount of time to wait (in seconds) for a server response before timing out. Use with care! If a non zero value is supplied this must be greater than the maximum time that the server will take to answer any query. Once the timeout value is exceeded the network or named pipe connection will be closed.