Setting Up the Session Parameters

 
There are three types of users in MTEACH:

• Administrator - sets up and maintains the server and its session and the user databases. Can both start and join all sessions.
• Moderator - can see all the session's parameters but can only change the session information field for the session he/she moderates (the text describing the session). Can start his/her own session and join other sessions to which he/she has access to.
• Student - can see only the session information and can join the sessions to which he/she has access to.

The first file is Adm.dat which is a file containing the administrative password. It is created by using a ASCII text editor and typing in one word, the password. For example, the file Adm.dat would contain one line of ASCII as follows:

 
secret_password

 
The second file is Types.dat (click here for the explanation of its format). For example, Types.dat would contain:

 .Audio
vat
rat
.Video
vic
.Whiteboard
wb
.3D Video
3dvideo

This file creates Audio, Video, Whiteboard and 3D Video media types for VAT and RAT tools used for audio, VIC for video and 3dvideo for 3D video media.

Once these files are created, the MSERVER can be started (with or without the extra parameters - see here). An example of starting the server:

MServer.tk port 12067 log 1

This would start the server listening on port 12067 and logging the events (default log file name is Log.dat). If the port and log parameters are not specified, port defaults to 23232 and log to 0 (no logging). Note that in order to run a TCL/TK script file, you have to have TCL and TK installed on the computer running MSERVER (only TCL is sufficient for running MSERVER).The server is now ready to receive requests from the client tools.

The administrator can now execute the MADMIN tool to set up new sessions. An example of starting the MADMIN:

 MAdmin.tk foo.ecn.purdue.edu/12067

This would connect MADMIN to the server running on the machine foo.ecn.purdue.edu listening on port 12067. If no parameters are given, MADMIN tries to open the file Servers.dat which contains the server machine names and ports. An example of Servers.dat would contain the following lines and should be created manually:

foo.ecn.purdue.edu 12067
boo.cc.purdue.edu 23000
fee.ecn.purdue.edu 56790

If Servers.dat is found, the user is presented with a list of these servers to choose from. If not, the user is prompted for the server name and the port number. To actually connect to the server, "Click here to connect" button should be invoked.
The administrator is then prompted for the username and the password. The administrator should enter "administator" as the username and the password should be the one previously entered in the file Adm.dat. If the password is correct, the bottom main window entry (a button) turns into "Connected to foo.ecn.purdue.edu."
A new session is now created with MADMIN by clicking on the Add button, selecting Session and then providing the necessary session information. Here is a sample list of actions which would create a test session named "Test Session":
 

• Click on Add button.
• Select Session. A new window will appear.
• Click on the Name entry box.
• Enter Test Session.
• Let us assume it is going to be a restricted type of session. Click on the Restricted radio button in the Session Type field.
• Assuming that the VAT application is going to be used for audio and VIC for video, click on the vat button located in the Available Tools/Audio field. The title of the entry field underneath is going to change to "Option arguments for Audio (vat tool):." We will then enter the arguments for the students (users) first, hence click on the User radio button to indicate that. Now click in the entry field above and enter the command line arguments for VAT (everything that would be needed to execute VAT). An example:

where user is the username of the session moderator and host is his/her host Internet address (in dotted quad format). In this example, VAT is started in the student mode (the option "-m 2") with its window entitled "Test Session" (the -C option), using the RTP protocol (the -r option), transmitting/receiving on the multicast address 224.22.22.22 on port 57593 and with the session moderator specified after "Xmoderator" argument.

Now we click on the Moderator radio button to indicate that we would like to enter the command line arguments for the moderator. For example:
 
-m 1 -C "Test Session" -r 224.22.22.22/57593
 
The argument -m 1 starts VAT in moderating mode.

Audio is set up properly now. For the video, click on the vic button located in the Available Tools/Audio field. Enter the option argument entry field in the same manner as for the audio. For example, for the user, the arguments can be:

 
-r 2 222.22.22.22/23456

 
and for the moderator:

 
-r 1 222.22.22.22/23456

 
The video is now set up properly. Additional arguments can be entered, such as the type of audio or video compression or maximal allowed bandwidth (click here for details).
 

• Click on the Session Info box and enter any relevant session information. For example:

 
Test Session, EE207

 
in the Sessions entry field. In the case of students, this field should be filled with the list of the sessions that he/she is allowed to attend. Note that the passwords and the session names are case sensitive, whereas usernames are not.

For reviewing the entered sessions or users, List Sessions (and then Get Global sessions or Get Restricted sessions) or List Users (and then Get User List or Get Moderator List) should be invoked. You can then double click on the session or user name for information (right click to remove the information window).

The session now has the proper information set up, along with the accompanying users and the moderator.

Starting or Joining the Session

The difference between starting and joining a session is that when starting a session, the multimedia applications are invoked with the moderator command line arguments by the moderator and when joining a session, they are invoked with the user command line arguments by the users.

When the moderator or the administrator wishes to start a session, he/she can start the MADMIN tool in the same way as described in the previous section, select the server where the session information is located and log in.

• Click on the List Sessions button. If you are logged in as the administrator, you can then select to list either the global or the restricted sessions. If logged in as the moderator, the list of the global sessions, the moderating sessions and the sessions to which you have the access to will be only displayed.
• Click on the session name and then select Session/Start Session from the menu. That will invoke all the necessary multimedia tools.

 
MStudent.tk foo.ecn.purdue.edu/12067

 
This would automatically connect them to the server running on the machine foo.ecn.purdue.edu. If no arguments are supplied, MSTUDENT attempts to open the file Servers.dat which serves the same purpose as described above. The rest of the student login procedure is similar to the administrator or the moderator login, with the difference being that after the password is accepted, the global session and restricted session lists are downloaded automatically (only restricted session to which the student is permitted to enter are downloaded).

The student can then select the session to join and click on the Join Session button. This will start all the necessary multimedia applications.

Asking Questions with the modified VAT and VIC

 
To ask a question, one should press the Question? button located at the bottom of the main VAT window. To enable or disable a student's transmission the moderator should select the appropriate student by clicking on the student's name.

For detailed information on how to ask questions or how to enable a student to ask a question, follow this link.