Access grid for Mac OS X

From GridInfo

This page summarises the information that is available from http://www.accessgrid.org and http://www.agcentral.org regarding setting up and running the Access Grid toolkit. It describes general details about setting up version 2.4 of the toolkit, with some specific details for use within the UK and with NIEeS support. The step-by-step guide with screen shots of every stage should make it easy to start using the Access Grid toolkit.

Downloading the software and installation

Figure 1: Main view of the access grid download site for Mac OS X.

FIgure 2: Download options for installation of the Access Grid package on Mac OS X.

Go to the Access Grid site (http://www.accessgrid.org) and click on the software download link. You will get the page shown in Figure 1. This gives you the option to choose installation instructions for either OS X 10.3 Panther or OS X 10.4 Tiger. Select the correct one for your system.

You will be directed to the page in the screenshot shown in Figure 2. You will need to select several installations:

• Python 2.3. This should be installed from the installation CD that came with your machine, but if not, you can download it using the link on the Access Grid download page.
• wxPython. You will certainly need to install this. Click on the Download link, which will direct you to sourceforge to download the software. Select the appropriate mirror site and download the software. Back on the main AG download page you also need to click on the second download link for the required additional package. This will fire up an installer window to install the software. Follow the installation instructions to install the package. Once the wxPython software has been downloaded a folder will open with the package to install. Click on the package wxPython and this will start the installer; just follow the instructions to install the package.
• The final dependency is the X11 package, which can be installed from your Mac OS X Install disk. From the install disk click on the optional packages. This will bring up the installer. Install the X11 package by selecting the box next to X11, under the ”Application” list item, and selecting install.
• The Access Grid toolkit itself can now be downloaded and installed. To do this click on the download link for the Access Grid 2.4 software. Once downloaded, you can open the download and click on the package. This will fire up the installer which will guide you through the installation of the Access Grid. Once you have completed this stage, the Access Grid is installed and you can start using it.

Launching the Access Grid tool

Figure 3: Access Grid launcher

Figure 4: Progress bar on launching the Access Grid

Open a finder window, go to Applications, and click on the Access Grid Toolkit. This loads the Access Grid Launcher, Figure 3, which is used on the mac to execute Venue Client and other Access Grid software.

To then launch the Access Grid properly, click on the big Venue Client button, which will cause the Venue Client to load. If you are a first-time user, you will be asked some questions such as your name, email etc and whether you are using a node or a user (choose user for a desktop access grid). Figure 4 shows the progress bar as it launches.

The Venue Client will then load with a default Venue Server address (Figure 5). For members of the UK academic community, the default address should be changed to https://george.ag.mcc.ac.uk:8000/Venues/default.

Figure 5: Initial view of the Access Grid venue server, when not in a venue

Figure 6: View of the Access Grid venue server from the lobby

When the venue client is loaded, it will take you into the Venue Server Lobby of the UK Access Grid Support Centre (Figure 6). You can then see venues/rooms (down the side of the Venue Client) into which you can enter. To enter any venue/room, click on the door. Once in a venue/room, you can leave by clicking on the "exit" door. It should be noted that whilst moving in and out of venues/rooms the video and audio tools ([vic] and [rat]) will open and close; this is slightly annoying but normal.

Once you are in a venue of choice, you can bookmark the venue so that you can go straight to it without having to navigate through the rooms and having to remember the george.ac.mcc.ac.uk URL. To save your current venue, go to the ”My Venues” menu and click on ”Add Current Venue...” menu item (Figure 7). This gives you a dialog box where you can decide what to call the venue. Click "OK", and if you then look in the ”My Venues” menu you will see the venue saved as a clickable item. Next time you launch the Access Grid you can click on this and you will immediately be taken to the venue/room without having to remember how you got there!

Figure 7: Option to select your current venue as one of the preset venues

Figure 8: Panel for selecting the unicast/multicast bridge

Figure 9: Panel for selecting the unicast/multicast bridge

If you have multicast enabled at your institute then you will probably already see and hear people immediately. If you don’t have multicast enabled, then you probably just see your name in the audio tool and a ”waiting for video” in the video tool. To be part of the group you will need to use one of the bridges that are available for the venue of your choice (note that bridges can be tied to venues, so you may not find the same range of bridges for different venues). Goto the ”Preferences” menu and then click on the ”Unicast” menu item (Figure 8). A dialog box (Figure 9) will appear that has a list of bridges. Choose one of these and then click "OK". This will reload the venue with you sending your video/audio via the bridge.

To use the bridge you will need to ensure that your institute firewall has some UDP ports open over a certain range for incoming and outgoing data: see Access Grid networking and firewall issues. The AGSC/Manchester bridge will pick the ports at random, meaning that you will need to have the full range open on your institute firewall. Other bridges may operated over a restricted range of ports, which has the advantage that your firewall will only need to have a small range of UDP ports open for it to always work. For example, the NIEeS bridges have a very narrow range of ports which do not change.

Fine tuning

The vic and rat tools have a number of settings, as described on the links. Some key settings are

• vic: You can change the quality of the video stream and the frames per second by clicking on the ”Menu” button on the video tool. Some important features include the rate which is controlled by the two slide bars at the top of the menu which set the maximum values for both the bit-rate in kilobits per second (kbps) and the number of frames transmitted per second (fps). The higher the rates the better the quality of the video stream, but the greater the demand on the network - and if your network cannot support the values you choose, the actual values can be much lower. The quality of the video you send is also controlled by the slide bar which has a ”quality” label next to it (the lower the value the higher the quality). Another feature is the ”Tile” combo box, this allows you to specify how many columns there will be for the thumbnail streams on the main window (useful if there are lots of participants).
• rat: You may need to change the sound levels for both yourself and other participants (you don't want to deafen other partipants, nor do you want to be difficult to hear). You may also want to play with some of the codecs to reduce the load on the network.

Troubleshooting

There are a few things that may cause you problems.

Small problems

Figure 10: option to look at node services

Figure 11: window to select services

• Some problems are caused by not remembering to check the transmit buttons on the vic and rat tools.
• You may have a trivial problem that your camera and audio systems are not properly set up. For example, if the camera is not properly set up, the transmit option in the vic menu window will be disabled. It is recommended that you eliminate such problems by checking sound in the "system preferences" application, and checking the camera works using "iChat".
• To test the audio tool is working correctly you can do a tone test and also see if your microphone is working. To do the tone test, click on the ”Options” button in rat. A dialog box will appear which shows some of your details. First click on the ”Category” combo box and select ”Audio” from the list. Then click on the ”tone test” button and you should hear a tone. To check the microphone, go back to the main rat window and click on the "Talk" checkbox. Talk into the microphone and the bar on the tool should fluctuate as you speak.
• Ensure that you have disabled audio and video in iChat if you have iChat running simultaneously.
• One reason why you may be unable to transmit video, with the symptom that in the vic tool the option to transmit is disabled, is because you only have a "Video Consumer Service" running (on the Mac OS X version this is not the default option). To transmit video you will need to add a "Video Producer Service" or simply have a Video Service which does both. In the ”Preferences” Menu click on the "Manage My Node...” menu item (Figure 10). The ”Access Grid Node Management” dialog will appear (Figure 11); this allows you to add and remove the services to suite you. There are several services that are available by default with the Access Grid toolkit, these include the Video Services and the Audio Services. By clicking on one of the services in the list box you can select to remove it by going to the ”Service” Menu and clicking on the ”Remove” menu item. To add a new service you go to the ”Service” Menu and select the ”Add” menu item - this will show a dialog which allows you to select a new service to add. If you don’t want to see yourself then choose the ”VideoConsumerService” and ”VideoProducerServices”. If you do want to see yourself then simply remove all other video services and add a ”VideoService”.
• Audio may not work properly if you select to use ”Echo Suppression” in the Audio option in the rat tool. If you have echo problems, use headphones, or a directional microphone, or a microphone with in-built echo cancellation.

Large problems

• Your firewall is not set up properly!