Redirection to the default portal used to be done by the index.jsp JSP page. This is not the case anymore, the index.jsp file has been removed and the welcome file in web.xml was removed too. Instead a specific handler in the routing table has been configured, the sole role of this handler is to redirect the request to the default portal when no other request has been matched previously:

<controller>

  ...

  <route path="/">

    <route-param qname="gtn:handler">

      <value>default</value>

    </route-param>

  </route>

</controller>