The Jitsi calling sound's been cut off

Dear all,

I have a question for Jitsi’s call quality. We’ve implemented Jitsi call on both android and ios platforms. But when we call from different places, we hear sometimes the sound’s been cut off.
I’ve uploaded the recording audio that conversation.
Please follow the link below: https://drive.google.com/open?id=1FQR9tnlnCVDobPLRLYLJ-uIO29QgQiks

You can see that at seconds below:

  1. 00:06
  2. 00:16
  3. 00:26
  4. 00:36
  5. 00:46
  6. 00:56

I saw that after 10 seconds it cut-off once.
Could you help me answer why this problem happens?

Thank you,
Thuan Tran