The default timeout is 30 minutes. You can specify a different timeout in the webapp.props file which is located in the AwareIMRoot/Tomcat/webapps/AwareIM directory.
where AwareIMRoot is the root directory of your Aware IM installation.
Open this file with any text editor and modify the following line:
SessionTimeout=1800
Note that 1800 indicates number of seconds. Put in any different number.
Also make sure that you re-start Aware IM after that.
Best Regards