Canvas LMS Bigbluebutton 0.9 integration audio problem and the solution!

[Mesut Aydemir]

Recently I have installed canvas lms and bigbluebutton 0.9 beta and when I try to join the conference, although I passed all the sound check test and click on MICROPHONE button (not LISTEN ONLY) both the teacher and the student were unable to activate the microphone option. In other words, they join the meeting listen only option. The source of the problem was, as explained by Fred Dixon, for voice bridge canvas was adding zeros before the five-digit number and the number becomes 20 digit and bigbluebutton was expecting a five digit number. Actually there seems to exist two solutions for this issue:

1- As a background, in early version of bigbluebutton (0.8) a similar problem existed: Teachers joins the meeting without any problem; students join meeting but although they click on JOIN AUDIO button, they were unable to hear the teacher's audio. For the bigbluebutton 0.8 version, this problem was solved as follows:

Modify the FreeSWITCH dial plan to be compatible with how Canvas is sending data, in /opt/freeswitch/conf/dialplan/public.xml look for the following block of XML

       <extension name="bbb_conferences">

      <condition field="destination_number" expression="^(\d{5})$">

          <action application="answer"/>

          <action application="conference" data="$1@wideband"/>

          <!-- <action application="conference" data="$1@wideband"/> -->

      </condition>

    </extension>

and change it to

    <extension name="bbb_conferences">

      <condition field="destination_number" expression="(^\d{5}$|^\d{20}$)">

          <action application="answer"/>

          <action application="conference" data="$1@wideband"/>

          <!-- <action application="conference" data="$1@wideband"/> -->

      </condition>

    </extension>

then do 

  sudo bbb-conf --clean

(See Fred Dixon's post dated 11.28. 2012 at https://groups.google.com/forum/#!topic/bigbluebutton-users/j1QLOAtLctg)

I thought, the problems were similar and decided to give it a try. However, in bigbluebutton 0.9 beta version, there existed NO block in the /opt/freeswitch/conf/

dialplan/public.xml as follows:

<extension name="bbb_conferences">

      <condition field="destination_number" expression="^(\d{5})$">

          <action application="answer"/>

          <action application="conference" data="$1@wideband"/>

          <!-- <action application="conference" data="$1@wideband"/> -->

      </condition>

    </extension>

Even so I added the following just above the following and did   sudo bbb-conf --clean

<!--
        You can place files in the public directory to get included.
    -->

It's working right now.

2- Another solution is on the canvas side. As explained by engmsaleh on https://github.com/instructure/canvas-lms/issues/478, it is possible to modify the app/models/big_blue_button_conference.rb file as follows:

Change

:voiceBridge => "%020d" % self.global_id,

To

:voiceBridge => "99999",

I haven't tested the second method, but it is said to be working on the above mentioned link. The second method assigns a static five digit voice bridge number.