Course13:IT Connect - 08.1 Conferencing

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Configuring conferences and maintain overview.



The purpose of the Conferencing App is to create conference rooms that allow multi-party conferencing. While ad-hoc conferences, which can be initiated over the phone, are limited to 3 parties, a multi-party conference can handle a larger number of participants. The actual number a gateway can handle depends on how many conference channels are available on this device. In case you wonder what a conference channels is, consider it simply as a hardware property of a gateway/device (e.g. an IP811 has 10, an IP3011 has 30) - we will go more into detail later (you will find the respective characteristics of your gateway device in the corresponding data sheet or in the CONF column of the table in fish-help.png How to implement large PBXs or on the devices screenshot.png home page).

Technically, the Conference Interface does the mixing of the participant's audio streams, merges them in to one stream and echoes it back to all participants. The video isn't mixed on the other hand. Only the video of the active speaker is transmitted to all participants.

So for a working conference, you need both the Conferencing App and an associated conference interface.

In addition to audio and video conferences, the Phone App also offers the possibility to share your desktop with other participants in the conference room (note that when using the web version of myApps, you can not share your desktop but you can see a desktop shared by somebody running native myApps).


If you want to configure conferencing you need to create a Conferencing object at first.
Therefore go to the PbxManager plugin called screenshot.png Conferences and press screenshot.png add a conference. A configuration dialog will appear which allows you to configure the following parameter which have to be unique in the system.
  • Name: This is the name of the Conference object
  • SIP: This value is used for the internal communication. You don't need to change it.
  • Number: Any number you configure here will be the prefix for your conference rooms. If you assign the number 60 and your room number is 10, you need to dial 6010 to get to the conference room.
Let's go ahead and create a Conference object called Conference, SIP conference and using 60 as Number.


If you call the conference room, you will probably expect to hear a greeting or a prompt to enter your PIN. Therefore the PBX needs to retrieve media files via HTTPS to be able to play an announcement.

You can use English announcement files or you can refer to fish-help.png our wiki to find the files in different languages.

These files are already converted, so you can video2.png upload them to the Files App right away:
  • open the Files App and create a new folder called conference
  • click on Mark on the upper right and then select only the new folder (you can also press and hold your left mouse key for a few seconds to see a check-mark next to it)
  • click the share icon on the right
  • a User and Password for the share must not be used as you only want to share the files internally
  • afterwards drag the announcement files you just downloaded to your conference folder
You then need to video2.png select the folder in the Announcements section of the Conference PbxManager.

(Further Hints) If you wonder how the plugin knows which of your shared folders to display: it simply looks in to all of those and considers only those, where a file input_room_number.<coder> exists in (which is one of the audio prompts used by the App).

Conference Interface

There are two types of conference interfaces. You can either use a purely software-based interface that uses only g711a or g711u as a codec, or you can use the hardware resources of a device to use as a conference interface.

To link the conference object to the conference interface you just have to press the screenshot.png search button which will show all conference interfaces on all previously provisioned gateways. If you can't see your IP811 you need to redo the step Adding a Gateway in the Managing Devices book. When your IP811 is visible you can screenshot.png select the conference interface you want to use. The software based interfaces are marked as Software Conference. The others use the hardware resource of the device.

Conferencing and Coder channels

Let's talk about the CONF interface which uses the hardware resources of the device. The purpose of the conference interface is mixing audio streams therefore a conference channel is used from each endpoint (e.g phone) connected to the conference interface. A conference channel is a limited resource in a gateway. There is no need to license it but you have to be aware that the number of conference channels differs depending on which innovaphone product you purchase.

If the caller is a VoIP endpoint, in addition to the conference channel, a coder channel (a.k.a. DSP channel) is necessary to connect the audio stream to the conference interface. Like conference channels, each gateway also has a different amount of screenshot.png DSP (or coder) channels. DSP channels needs to be licensed.
Let's take an example. Your IP411 has 6 coder channels but no conference channel. Therefore, we cannot use the CONF interface as a resource for conferencing because there is no conference channel available. In this case, we could use the software conference interface of an IP411. Note that software conferencing requires PBX channel licenses to work.

Going back to our configuration screenshot.png the plugin will show you how many channels are available on your device. The amount of actual used coder channels is configurable if you want to reduce the maximum number to ensure the availability of coder channels (e.g. for Fax, analog or ISDN calls).

Now let's get practical and video2.png link the conference object to the conference interface on your IP811.


The last mandatory step to get your conference object up and running is to create rooms for dial-in.

A room conceptually is the place where a single conference happens. The Conference App can manage multiple rooms and users will select a specific room by dialing its corresponding extension. All rooms share the resources of the conference interface we have linked to the Conference App in the previous step.

For audio conferencing, all incoming audio streams are converted in to a common PCM format before they are mixed. The result is converted back to the original codec used by the participant. This is what the coder channels are needed for. As a result, callers can call in using different codecs.

For video conferencing (and app sharing) however, no mixing is done. The incoming video stream that also has audio activity is echoed back to all participants (all other video streams are muted). No transcoding takes place. This is why you need to fix the video codec to either H.264 or VP8 (we recommend VP8 because H264 is not supported by myApps for Android and myApps windows native client). All participating video equipment must support the video codec you have selected for the room in order to take part in a conference in this room.

The PBX will create an App for each room you create. This App may be assigned to users and allows to management a conference in a given room in real-time.

To video2.png create a room, proceed as follows:
  • click on screenshot.png Add room and a screenshot.png new dialog will appear which allows you to configure the following parameter:
    • Display name
      This will be the name of your conference App. Please use HQ Conf
    • Number
      Together with the previously defined prefix (60 in our case) this number will be the extension of your conference room to dial in. You can leave the default (which is 01)
    • Reserved channels
      You can leave the default (which is 0). Callers can always call in to a room even if the number of participants then would exceed the reservation, as long as there are free conference (and coder) channels available. This will take into account the channels which are reserved by other rooms. The reservation of channels takes place when the first participant calls in to a room. In other words: if you call in to a room with reservations, the call will only succeed if there are enough free channels available to satisfy the reservation. If so, you can be sure that there will be enough channels for participants calling in later. If not, you get a busy right away. This avoids setting up a conference where some of the participants can not call in due to missing channels
    • PIN
      To protect non-authorized access to this room, you can define a PIN. If you don't set any PIN, the room is not restricted and everybody can join. We suggest you use 0000 (in the training, not in real life wink). Note that the PIN Must be either 4-digit or empty
    • Video coder
      You can define a preferred video coder here. As mentioned above, use VP8
  • do not forget to click on OK wink

Go for it!

We can now try it and call 6001. We should hear a welcome message asking us for the PIN (as we already selected the room number. If we'd called 60 only, we would be asked for the room number first).

Most likely, this will not work at this point and your call will be disconnected with an error message on the display. So why is that?

As we discussed, we need conference and coder channels for the conference to work. Also, coder channels need to be licensed. As we are using the conference interface on the IP811, we would need to install these channel licenses on the IP811 (hardware related licenses are always installed on the respective device itself. Software related licenses however are installed on the PBX and distributed in the system). As we don't have licenses in the course, we need to enable test mode on the IP811.

You probably already know how to do that using Devices access to the advanced UI. If not, see link_intern.png chapter Test Mode in Configuration Hints for Lesson on Setting up the basic System. The only difference is that you must do it on General / License rather than on the IP411LEFT this time.

(Further Hints)In case your conferencing app isn't working as expected and you already did the Reverse Proxy configuration, we recommend to read section Allowing Registrations via Reverse Proxy in The individual Device User Interface to fix it.


As soon as you created a conference room, an App is created by the PBX. You can assign this App to any user, which will result in a new App in the user's All Apps overview.

Yeah more Apps!

Let's assign our new App to every user.
  • open the Config User template in the Templates plugin of the PBX-Manager
  • go to Apps and click the check-mark next to HQ Conf
  • afterwards go to your All Apps overview and put your HQ Conf App on your home screen

The Conference App

When you start screenshot.png the App you'll see a header bar with multiple options.
  • You can start a group chat by clicking the screenshot.png chat icon on the upper left
  • by pressing the screenshot.png handset icon you will call the conference room if you aren't already connected
  • the room's screenshot.png full extension and the number of already connected participants and the number of reserved channels screenshot.png are visible at a glance
  • you can see the screenshot.png current PIN and edit it by pressing the pen icon
In the list below you can
  • screenshot.png mute a participant (e.g. if noise is disturbing the conference)
  • set the participant to screenshot.png exclusive speaker mode (that is, all other participants are muted)
  • or screenshot.png disconnect a specific participant
To identify the speaking person the participant is highlighted and screenshot.png marked as Speaking.
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