If you are not familiar with GroupWise WebAccess, review GroupWise WebAccess Overview
in Installing GroupWise WebAccess
in the GroupWise 7 Installation Guide.
As you plan WebAccess in a clustering environment, you must keep in mind that you will plan and set up two separate WebAccess components:
WebAccess Agent (gwinter.exe) that will be associated with a GroupWise WebAccess domain
WebAccess Application (a Java servlet) that will be added to your Web server