Secure Global Desktop 4.40 Administration Guide > Applications, Documents, and Application Servers > Using Shadowing in the Classroom

Using Shadowing in the Classroom

You can use SGD shadowing to create a "virtual classroom" where the "pupils" in the classroom shadow an application being demonstrated by a "teacher".

To be able to do this, you have to create a teacher's application object and a "classroom" application object.

Creating the Teacher's Application Object

1. In the SGD Administration Console, create a new Windows or an X application object.
2. Click the Launch tab and type one of the following in the Login Script field:
   • unixclass.exp if the application is an X application
   • winclass.exp if the application is a Windows application
3. Click Save.
4. Configure any other settings you want for the teacher's application.
5. Click the Hosting Application Servers tab and select the application servers that can run the application.
6. On the Assigned User Profiles tab, assign the teacher's user profile to the application.

Creating the Classroom Application

1. In the SGD Administration Console, create a new X application object.

   Note The classroom application is an X application even if the teacher's application is a Windows application.

   The General tab displays.

2. Click the Launch tab and configure the application as follows:
   • In the Application Command field, type /opt/tarantella/bin/bin/ttashadow.
   • In the Arguments For Command field, type -readonly -silent -pointer $SHADOWDISPLAY.
   • In the Login Script field, type pupil.exp.
   • In the Environment Variables field, type MYCLASS="name_of_teacher's_application" for example, MYCLASS=".../_ens/o=applications/ou=Finance/cn=XClaim"
3. Click Save.
4. Click the Presentation tab.
5. For Color Depth, select 16-bit - thousands of colors and click Save.
6. Configure any other settings you want for the classroom application.
7. Click the Hosting Application Servers tab and select the application servers that can run the application.

   The ttashadow application is only available on hosts where SGD is installed.

8. On the Assigned User Profiles tab, assign the user profiles of all users in the class to the classroom application.

Notes

• The teacher must launch their application first, then the pupils launch their classroom application to shadow the teacher.
• The classroom can only shadow Windows or X applications.
• Only one person can use the teacher's application at any one time. If more than one person starts the teacher's application, the classroom shadows the application that was started last. For this reason, only give the teacher's application to one user. If you have several teachers, create separate application objects for each of them.
• The classroom application must have a color depth of at least 16-bit.
• The display size of the classroom application must be at least the size of the teacher's application. For the best results, use an independent window for the classroom.
• When the teacher starts their application, information is stored on the SGD server about which application can be shadowed by the classroom. This information is not copied to the other members of the array. This means that if the classroom application is launched on a different SGD server to the teacher's application, the classroom launch fails because the information about which application can be shadowed is not be available. You can use load balancing groups to guarantee that the teacher and classroom applications are launched on the same SGD server. You must set the load balancing group for the application server and the SGD server. Otherwise, only use classroom shadowing in an SGD array containing a single SGD server.

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