Frequently Asked Questions (FAQ)

General questions | Using Gong | Gong and Moodle | Installing Gong

General questions about Gong

Questions about using Gong

Questions about Gong and Moodle

Questions related to installing Gong

Is Gong free?

The Gong system is free for non-profit use. It can be downloaded via the download page.

Is Gong open source?

Gong is free for non-profit use. However, we will not release the source code for the current version. It is possible that Gong will become an open source project in future versions. One reason for not releasing the source now is that we want to do major code re-structuring first, including web service support and other features.

Why is it called 'Gong'?

The name originally comes from the Cantonese word for 'speak', which is 'gong'. Also, in English a gong is a loud cymbal. So in some way the name reflects the Chinese and English teaching origins of Gong, although these days Gong is used to teach a large range of languages.

What is the size of Gong? (From the user's point of view).

If you run Gong as an applet, the size is 1.5Mb.
If you run Gong inside Moodle, then you are running the same applet (1.5Mb).
(The browser will cache the applet after it has been loaded once, so it doesn't need to be downloaded every single time you use it. In the case of Internet Explorer and probably other browsers, the applet will be removed from the browser cache when the browser stops).

If you run Gong as an application, about 22Mb is installed on your hard disk.
(This greater size is mainly because Java is also included within the Gong application).

Please go here for more information about the Gong applet and the Gong application.

Can a Windows/ Mac/ Linux machine run Gong? (From the user's point of view)

Just about any computer can run the Gong applet. People use it with Windows, Mac and Linux machines (although we develop it on Windows). It only needs the Java environment to be installed on your machine. You can check whether your machine can run Gong using this web page.

For the Gong application version, at the moment we have only developed an installer for Windows.

What does the 'S' and 'C' mean in the version number, such as 5.0.6C and 5.0.6S?

People use Gong by running a program on their computer. We call that program the 'client' program. The version number of that program is the number with the C on the end. The client program talks to the Gong server. The version number of the server is the number with the S on the end. Sometimes we release a new version of the client program without making any changes to the server. So that means the number with the C at the end of it may be different to the number with the S at the end of it.

What audio format does Gong use?

Gong uses one audio format for voice messages and another for recorded real-time (streaming) chat messages.

For voice messages WAV file format with the IMA ADPCM codec is used. For real-time (streaming) chat messages voice files are stored using the Speex codec, a free speech codec. You can learn more about Speex in

Does Gong require a broadband connection to be used?

Gong is the same as any other Internet-based software. It performs better when a broadband connection is used. For example, it is much quicker to stream audio from the Gong server when you have a fast connection.

However this does not mean that Gong would not work with a slow connection such as when using a 56k dialup modem. As a reference we have done some measurements on the time needed to post a voice message using a 56k modem. For a short voice message (~30 seconds duration) it takes around 20 seconds to post the message to the server. For a longer message (~2 minutes duration) it would take approximately 1 minute and 20 seconds to transfer the message to the server.

People have used Gong with dialup modems in the past. In that setup the Gong application was used rather than the applet (to save the download time of the applet) and it was distributed on a CD. In summary, Gong can be used with a slow connection although we would strongly recommend using a broadband connection.

How can I record myself?

There are two ways to record yourself in Gong.

  • Up to 5 minutes - Firstly, there is the obvious way: click on the 'Compose' button. A window will appear where you can record yourself and/or write some text. You can edit the audio if you want, and format your text using the message editing controls. You can use any language for the sound, and any language (almost any language) for the text. Press 'Post' to send the completed message to the board. Using this method everything is kept in memory until you press 'Post'. You can record up to about 5 minutes of audio using this method.
  • Unlimited recording time (Not applicable to using Gong inside Moodle) - Secondly, there is a method which will give you unlimited recording time. Go to a board which shows the 'user list' (the list of people currently in that board). You will see a button called 'Start Chat'. Press that, and select 'Broadcast'. Then press record. This method means that everything you say is streamed directly to the server. Because it works in that way there is no limit to the maximum length of time you can record (in theory). You can go here for more information.

How do I record from something else into the Gong system other than using the microphone?

You can record using other input devices by adjusting the sound settings in your operating system.

By default the input device for recording is probably the microphone, for any system. By changing the input device to other media you would be able to record from other things instead of the microphone.

For example if you would like to record a CD you can adjust the input sound settings so that audio input comes from the system audio output and not from the microphone. If you are using Microsoft Windows you can use the audio control to do this, select Start>Programs>Accessories>Entertainment>Volume Control, select 'Properties' then 'Recording', and you will gain access to the audio input control. (Exact instructions depend on different versions of Windows). After you have done that you can, for example, start playing the CD on your computer, and then press Record in Gong. The audio will then be recorded in Gong.

For detailed instructions please go here.

Gong seems to be working fine but I can't hear anything. Any ideas why?

Here are the main reasons we have encountered when users have this problem.

  • Your computer is playing the audio, but at an extremely low level. You need to increase the volume level. For Windows, you can do this by selecting Start>All Programs>Accessories>Entertainment>Volume Control, select Options>Properties, select 'Playback' and press OK. Then you can increase the levels of the relevant sliders such as the 'Volume Control' and 'Wave' sliders. Also, make sure those two sliders do not have the 'Mute' or 'Mute all' box selected.
  • The recording may have been made with a broken microphone, or with the microphone not plugged in, and so no sound was recorded, only silence. Gong will warn you when a silent recording is made, but perhaps the person who made the recording ignored the warning.
  • There is a volume control inside Gong (a kind of multicolour vertical slider on the right hand side of the GUI). Perhaps this has been moved too low. Try pushing it higher.
  • If you are using loudspeakers, perhaps they are not plugged in to the computer, or they are not turned up loud enough.
I have made a voice recording in the system but when I play it back it contains horrible noise.

Here are some of the more common reasons we have encountered:

  • You made your voice recording under a noisy environment, or you have a bad microphone. If this is the situation then you will need to move to a less noisy environment, or change your microphone.
  • You are 'eating' the microphone. Most microphones are not designed to work when they are placed right next to the mouth. Try having a bit of space between your mouth and the microphone. Also, don't put the microphone directly in front of your mouth. Instead, put the microphone to the left or right of the mouth.
  • We have found that it is very common for extra noise to be added by a laptop when sound is recorded and the laptop is plugged in to the power supply. We have experienced this happening on several different makes and models of laptop. The 'noise' is then picked up by any audio recording software - the problem is not related to Gong in itself. However, there is no problem when the laptop is running from the battery. Therefore, one solution is to simply unplug the laptop power cable before making the recording.
I get 'Audio Device Busy' or 'Audio Unavailable' when I try to use Gong. Why?

This means that another program on your computer is already using the audio capabilities of your machine and doesn't want to share them with Gong (or any other audio software). The solution is to stop the program which is using the audio system, and then come back to Gong. Possibly, you need to re-start Gong.

I clicked on a link in a Gong message, but it didn't open in a new browser.

Probably this is because your browser has a 'popup blocker'. Most of these popup blockers let you hold down a 'hot key' while you click on the link, and then the window will open. For example, if you have the google toolbar installed it will block popups, but if you hold down the CTRL key while you click on a link in a Gong message it will successfully open in a new window.

Alternatively, disable the popup blocker.

How do I do voice indexing in the system?

You can make voice indexing for any message with both voice and text. The speech should match the text otherwise the voice indexing would not be correct. The following is the steps:

  1. Compose the message by clicking on the 'Compose' button
  2. Record the speech and type in the transcript
  3. Select the text you would like to index (might not be all the text)
  4. Press on the 'Index' button
  5. After indexing you should be able to see the 'Idx' mark displayed on the timeline of the message
  6. If the timing is a bit wrong you can manually adjust it so it is correct. To do this, first finish the indexing and post the message. Then select the message in the board, and press Analyse. Press the small black rectangle so that you can see the voice information with the indexing lines. Then locate the index line you want to move, and click and drag it to the desired time.

You can find more information from the user guide of the Gong system.

To generate a voice indexed message you need to use Windows when you run Gong. But to 'use' an indexed message, any platform is fine.

Why do I need to click on the applet before it works inside Internet Explorer?

Microsoft introduced a new security feature in May/June 2006. For an applet to run inside a web page the user needs to first click on it (anywhere). Then he/she can access the applet in the usual way.

If you don't like this 'feature' then one solution is to use the application version of Gong. Alternatively, use another browser such as Mozilla Firefox or Opera.

Help! I accidentally deleted an entire board. Can I get it back?

Yes, it is possible. When an entire board is deleted (in the Gong board selection GUI) it appears to be deleted but in reality is moved to a special area. Your Gong system administrator would be able to restore the board. See this FAQ question for more guidance.

I have a font installed on my system. Why is it not shown on the font selection when I try to format a text message?

Gong is built using the Java technology. When Java uses and displays fonts on a system it uses the Unicode mapping to identify the characters.

However if a font is not designed based on Unicode Java will fail to display the font properly. Please click here to check the display of fonts in your system using a Java applet.

The Gong program will automatically check every font and use only those which are supported by Java. Your font may be one which is not Unicode-based and therefore it is not shown in the font selection when you format a message.

Font selection is one of the styled text formatting supported in Gong.

Can I install and run the standalone version of Gong on my USB drive?

It is certainly possible to install and run the standalone verion of Gong on a USB drive, given that the machine the USB drive is attached to has an Internet connection.

The Gong application requires only the files in the installation location in order to run. Therefore it is sufficient for it to run even if it is installed on a USB drive.

What can Gong do with Moodle?

Gong can be used as a module inside Moodle. That means many Gong features can be used to support teaching inside moodle, including:

What features of Gong don't work with Moodle?

The following features of Gong are not currently accessible when using Gong together with Moodle:

What versions of Moodle does Gong work with?

We have checked Gong works OK with Moodle 1.5, 1.6, 1.7 and 1.8. The Gong Moodle module was developed using Moodle version 1.6.

If I archive (backup) Moodle, will it automatically archive the Gong voice boards as well?


Gong is actually a completely separate system. If you archive just Moodle you will not be archiving all the text/audio messages in the Gong voice boards. You need to also archive the Gong directories and files.

Do Gong and Moodle have integrated student activity reports?

At the moment there is no integrated activity reports between Gong and Moodle.

As an interim measure you can consider using the information available from inside Gong. In this way you can see exactly what each user has been doing.

You can do this when you run Gong inside Moodle by clicking on the '?' in the top right hand corner, and then selecting 'Statistics'. Then type in the date period you want to check (or just leave it the same if you want to check today) and press 'Board Stat'. You will then see lots of statistics. Scroll down to 'User statistics' to get information about what every student has done - click on the various things to see how many messages the student has posted, how much time they have recorded, how much text they have typed, and so on.

To further process student statistics you can even press 'copy', go over to an appropriate program such as notepad, and then paste the data into that program and save it. Or, just press 'save' inside Gong. The data file can then be imported into any appropriate program such as Excel for further processing.

Another related feature is search - if you want to know what a student has done, you can click on 'Find' or press Alt-F, enter the student name, and press enter. You can then find each message that the student has recorded.

Can I use Gong with other Learning Management Systems (LMS)?

Technically, it should not be a problem to integrate Gong with other LMS such as WebCT and Sakai.

If you wish to do it yourself then you are welcome to examine the code of the Gong moodle module (which is written in PHP) to see how the integration takes place, and use the same methods to integrate Gong with another system.

Is it possible to install the Gong server in the machine hosting Moodle?

Yes it is possible to host both Moodle and Gong in the same machine.

Moodle and Gong use two different types of web servers (Apache and Tomcat respectively). Assuming you have Moodle installed in your machine you would need to install an additional Tomcat web server on top of the Moodle installation. However the Tomcat web server should use a different port number to the one used by the Apache server (i.e. Moodle). For example if Apache server is using port 80, you can set the port number of the Tomcat server to be port 8080. And subsequently when you configure the Gong server the value of the parameter base URL should contain the port 8080 as well. For details, please refer to the Gong Moodle module instructions and the Gong installation Instructions .

After the installation of Gong and Moodle, I have created a Gong activity in one of my courses. However the Gong activity displays a message saying "User parameter is not correct". Is there any problem with my installation?

There are only two reasons we can think of:

  • Your browser has a high security settings so that the Gong applet is not allowed to make a connection to the Gong server. You can try other browsers such as Mozilla Firefox or Opera to access the Gong activity.
  • Your Moodle cannot communicate with the Gong server properly through the authentication port which is port 8001 by default. For example there may be a firewall blocking any communication between Gong and Moodle. Or, another system has already occupied the authentication port such that the Gong server cannot listen through that port.
How can I enable Chinese Pinyin and/or Cantonese Yale support for the Gong activities in Moodle?

You can enable the Chinese input for Pinyin (Putonghua) and Yale (Cantonese) in the Gong module inside Moodle by changing the parameter 'ChineseInput' to 'true' in the config.php inside the directory of the module, i.e.

// Allow user to display the Chinese input
// Please enter whether special Chinese support (PinYin and
// Cantonese Yale) is enabled.
$GONG_CONFIG['ChineseInput'] = 'true';

By then when you create a Gong activity in a course you will be able to select to show either the Chinese Pinyin input interface, the Cantonese Yale input interface or both in the corresponding Gong activity.

After the installation of Gong and Moodle I have got a message saying "Cannot connect to Gong Server via Gong Server Authentication Port: port number". What did I miss during the installation?

In addition to the possibilities mentioned on the error screen, this can also be caused by not setting the "Auth.AccessList" parameter in the gongServer.ini. This value should contain the domain name or IP address of the Moodle server so that the Gong server can listen for any authentication connections from the Gong Moodle module.

Please note:

  • You will need to restart the Gong Server for changes to take effect.
  • If the output of the Gong server (during startup) includes the line "Listening for authentication session information on port number" (the default value for port number is 8001) that means something else is causing this error, which is described in this FAQ.

This FAQ is based on the MoodleDocs for the Gong module written by Filip Gieszczykiewicz.

After the installation of Gong and Moodle I have got a message saying "Incorrect user parameters. Please contact your web administrator for more information". What did I miss during the installation?

You can look at one of the Gong server log files. The log files are located in the "logs" sub-directory inside the Gong directory. The log files are called error_date.log. Please try to search for the following text:

validateSessionLogin;Failed to validate the user

If your log file contains this text that means the user, who has logged into Moodle and tried to access Gong, does not exist in the user database of Gong. The solution to this problem is to create a user, using the Gong administration module, which has the same username and password as the one that has used to log into Moodle.

If the text is not in the Gong server log files the problem may be because of one of the reasons described here.

This FAQ is based on the MoodleDocs for the Gong module written by Filip Gieszczykiewicz.

After the installation of Gong and Moodle I have got a message saying "Incorrect board parameters. Please contact your web administrator for more information". What did I miss during the installation?

You can look at one of the Gong server log files. The log files are located in the "logs" sub-directory inside the Gong directory. The log files are called error_date.log. Please try to search for the following text:

getAuthSession;Board name cannot be empty

The error means your Gong server does not have the default "Moodle board".

In order to make the integration work you have to use either the Gong application or the Gong applet to create a board called "Moodle" first (this requirement will be obsoleted in the next version of Gong). To check, login as admin using either the Gong application or Gong applet and verify that a board called "Moodle" exists.

If the board does exists and you still have this problem please check the following:

  • The name of the "Gong base path" (set for each Gong activity) does not contain a forward slash ("/")
  • The entry in the file mod/gong/config.php for line $GONG_CONFIG['GongBasePath'] matches exactly the "Gong base path" for the Gong Activity in Moodle. (for example, all of them are '/Moodle').

This FAQ is based on the MoodleDocs for the Gong module written by Filip Gieszczykiewicz.

I want to run the whole Gong system (client and server) on my own machine, not through the web. Is it possible?

Yes, you can have the whole system running on your own machine. Just follow the instructions to install Gong and Tomcat on your own machine in the usual way. Then, when you set the host name in the file gong.ini, you can enter 'localhost'. Then when you run the Gong client it will happily communicate with the Gong server running on the same machine.

After I have successfully installed the Gong server, the Gong board always gives me 'Failed to connect to server' when I try to log on the Gong system.

It could be one of the following problems:

  • The Gong server is not running properly

    You need to check whether the Gong Server is running in the machine. You should have the Gong Server console running in the server machine.

  • Your Internet firewall is blocking the access of the Gong board

    By default the Gong board uses the port 8000 for communication with the server. Therefore, if the port 8000 is blocked by any Internet firewall, the client would not be able to connect to the server properly.

    Please contact your network administrator to check the settings of the machines.

  • You do not have Internet connection in the machine running the Gong client software.
I have installed the Gong Server but the Gong board fails to play any recorded sound file.

Any sound files in a Gong board are stored in the server machine. In order to get the sound data, you have to install and start up an Apache Tomcat Server. With the server, sound data will be downloaded via a HTTP stream.

Can the Gong server be installed in operating systems other than Microsoft Windows based systems?

The Gong Project is implemented with Java technology, which is platform independent.

The development is done and tested in a Microsoft Windows based environment (including Windows XP and Windows Server 2003) as well as in a Fedora Linux installation.

The Gong server should work in any system supporting Java. We have made an installation package for installing Gong on Microsoft Windows as well as one for Linux based systems.

To use the server in other systems a script has to be written so that the class gong.GongServer is executed. The class can be found in the gong.jar file included in the installation.

What ports does Gong use?

Gong uses the following ports.

  • TCP 80 - Gong administration module, used for:
    • normal web page access
    • audio file transfer to client.
  • TCP 8000 - Gong connection port.
  • UDP 6970, UDP 7070, TCP 7070 - for streaming of audio between client and server.
  • TCP 8001 - Gong authentication port, used for LMS integration

The ports listed above are the default Gong settings. The ports can be changed by editing the gong.ini (for the client) and gongserver.ini (for the server) files.

If you are using Gong in Moodle the following ports are used:

  • TCP 80 - Gong administration modulea and audio file transfer
  • TCP 8000 - Gong connection port.
  • TCP 8001 - Gong authentication port.

If there is a firewall between your computer and the Gong server which blocks any of these ports then Gong won't work properly.

(If you use some kind of login authentication system with Gong such as CAS authentication, then that process will use a special port not mentioned above in order to perform the authentication).

How can I backup Gong?

The easiest option is to backup the whole directory where you have installed your Gong server. Alternatively you can backup only the directories containing the XML and voice data. These directories are:

  • <Gong directory>/data
  • <Gong directory>/logs
  • <Gong directory>/voices
  • <Gong directory>/admin/data

To restore the data you can shutdown the Gong server, overwrite the directories with your backup data and then restart the Gong server.

What is stored in the server trash directory?

Whenever a user deletes a discussion board using the Gong client program the entire board data is stored in the trash directory, i.e. <Gong directory>/trash, ordered by the date of deletion.

If you are sure that the deleted data is not useful anymore you are welcome to delete the content of the trash directory to free up the disk space.

To restore the deleted data you can copy the data back to the appropriate places.

  1. The trash/board directory should be restored to data/board directory
  2. The trash/voices directory should be restored to voices directory
How much space do I need for the Gong server?

The Gong server installation requires around 60Mb hard disk space. By estimating the amount of space used by voice messages we can give a rough idea on how much space a Gong server needs over a fixed period.

Assume you are running a course for a year and there are 50 students in the course, and each student leaves a 5 minutes voice message in the system every week. Then the required disk space is:

Disk space required for a 5 minutes message ~= 2Mb
Number of messages per student in the course = 52 messages
Total amount of space used = 2Mb * 52 messages * 50 students ~= 5G

Using a similar estimation, if each student leaves a message on the board every day the amount of space required would be:

Total amount of space used = 2Mb * 365 messages * 50 students ~= 36G

Even if a student leaves message every day, which is extremely rare, the total size of disk space required is not huge compared to the typical size of hard disk nowadays.

I am using the Gong server version 5.0.0S/5.0.1S/5.0.2S on a Linux system. Why do I get 'Failed to retrieve board list' after creating a discussion board?

The Gong server failed to maintain the board data because of a bug in the Linux implemention of the Java runtime environment.

The affected version of the Gong server is from 5.0.0S to 5.0.2S. Please install the latest version of Gong if you have encountered this problem.

From the Gong documentation the Gong server appears to be working on its own hardware and web server. Is it possible for Gong to work on a system where there is already a web server?

Yes Gong can work on systems where there is already a web server. If the web server is an Apache Tomcat web server you can share the web server between Gong and any other applications running on that server.

However if the web server is not Tomcat then you would have to install a copy of Tomcat server, possibly running on another port. It is because Gong requires the use of a Tomcat web server.

I have installed the Gong server following the setup instructions. However when I use the client to connect to the server it says: "The server is not available at the moment. Please try again later." What is the problem with my installation?

The error means that the client cannot connect to the server. The reason can be:

  • The hostname that you have specified in the client does not match the server you are using.
  • The port in your client does not match the server port which you have specified in the server (the default port is 8000).
  • Your client is behind an Internet firewall which prevents your client from connecting to the server. (This may happen in some intranets which do not permit Internet traffic in any ports that they do not use)
I have set up the Gong server on a Windows system. I can only run the Gong server by double clicking on gongServer.exe. I don't want to stay logged into Windows to run it. I know Tomcat can be executed as a service. Would it be possible to run the Gong server as as service as well?

Unfortunately you need to run the Gong server by using the executable because it is executed directly and is not integrated as a Tomcat service right now.

When a user composes or replies to a message, the toolbar for Pinyin input does not show up. How can I add this option?

First you need to enable the Pinyin input in the parameters for the Gong program. In case you are using the Gong applet, you would need to have the "Message.ShowPinyinInterface" set to true, i.e.

<applet name="gong" archive="gong.jar" code="gong.GongApplet" ...>
    <param name="Message.ShowPinyinInterface" value="true" />

Otherwise if you are using the Gong application you have to enable the same parameter in the gong.ini file, i.e.

# Whether to show the Pinyin user interface on the message composition window.
# The value is either 'true' or 'false'. The default value is 'false'.

How can I stop the Gong server?

It depends which way you are running Gong:

  • You are running the Gong server in a Microsoft Windows machine.

    You can stop the Gong server by closing the console window of the Gong server program. For example, you can locate the program in the Windows taskbar (the program list, usually shown at the bottom of the screen). Then you can close the program by clicking on the close button (the cross) at the top right hand corner.

  • You are running the Gong server in the console (UNIX shell) of a UNIX based machine.

    You can stop the Gong server by first selecting the console in which the Gong server is running on. Then press control-C, with that window in focus, to kill the Gong server program.

  • You are running the Gong server as a background job in a UNIX based machine.

    You can stop the Gong server by killing the Gong background job. Typically you can retrieve the job number by using the 'ps' command. The job number for every job on the machine will be listed. You need to identify the one which runs 'java -jar gong.GongServer'. Once you have the job number you can use the 'kill' command to stop the background job.

Do I need to have a Gong server to run the Gong application/the Gong applet/MiniGong/NanoGong?
  • For the Gong program/applet (described here):

    You need to have a dedicated server (a machine) to run the Gong server on. This server has to be able to run the Tomcat Web server as described in the Gong installation Instructions .

  • For the MiniGong applet (described here):

    The MiniGong applet is a 'Mini' version of the Gong applet with selected features and different display. The server requirement for the MiniGong applet is exactly the same as the Gong program/applet because both the Gong program/applet and MiniGong applet use the same Gong server program. That means if you use the MiniGong applet you still need to have a dedicated Gong server to be installed.

  • For the NanoGong applet (described here):

    The NanoGong applet can be used by itself on any web page. That means it does not require any Gong server installation. The only requirement is that you need to have a web space (a place to put web pages) to put the NanoGong applet on.

I do not have the equipment to install the Gong server. Is it possible to install and run the Gong server in an Internet hosting company?

Yes you can install and run the Gong server in an Internet hosting company. There are two requirements in order to make Gong running using an account in those companies. First the account has to support the Tomcat Web server (in particular version 5.0.28). Second you need to have the authority to access UNIX console using your account.

For example we have successfully installed and run Gong in a hosting company called which provides Tomcat service as well as UNIX console accessibility. (We need to ask for turning off the PHP 'safe mode' when we install Moodle)

I cannot get the grouping function to work in the web administration page. It does not give me any response or error when I try to attach users to a group. Is there any problem in my Gong server installation?

You do not have any problem in the Gong server installation. The reason for the failure in using the grouping function is because that particular webpage is not compatible with Mozilla Firefox. Please can you use Internet Explorer, then it will work without any problem. This will be addressed in the next release.

Alternatively you can download the file group.jsp from here, which contains the fix for the problem. Please replace the file in the following location: <gong directory>/admin/ .