Audio Jitter Issue with BBB 2.7.15

[Mohamad Sr]

Dear all,

I am currently running a VPS server with the following specifications:

• OS: Ubuntu Linux 20.04.6
• Memory: 48 GB RAM
• CPU: 12-core
• Bandwidth: 1000 Mbps

I have installed BigBlueButton (BBB) version 2.7.15. While the server should theoretically handle up to 100 users based on the documentation, I am encountering significant audio jitter issues during meetings.

Issue Details:

• Problem: Audio jitter increases significantly when the number of users exceeds 10.
  • At 10 users, jitter becomes noticeable.
  • At 14 users or more, jitter reaches 180–220ms or higher.
    
    
• Observation: There are no issues with screen share audio, even with up to 100 users in a session. The problem occurs specifically with users' voice (speaking) audio.  

Server and Configuration Details:

Here is the relevant configuration information for my server:

1. BigBlueButton Server Version: 2.7.15 (786)

   • Kernel Version: 5.4.0-200-generic
   • Distribution: Ubuntu 20.04.6 LTS (64-bit)
   • Memory: 48 GB
   • CPU Cores: 12

2. Configuration Files Overview:

   • bbb-web.properties:
     • bigbluebutton.web.serverURL: mydomain
     • defaultGuestPolicy: ALWAYS_ACCEPT
     • defaultMeetingLayout: CUSTOM_LAYOUT
   • nginx:
     • server_name: mydomain
     • ports: 80, 443 ssl
   • FreeSWITCH:
     • local_ip_v4: xxx (public IP)
     • external_rtp_ip: xxx (public IP)
     • external_sip_ip: xxx (public IP)
     • UDP Port Ranges:
       • FreeSWITCH: 16384–24576
       • kurento: 24577–32768
       • bbb-webrtc-sfu: 24577–32768

3. Additional Notes:

   • recordScreenSharing: true
   • recordWebcams: true
   • Video Codec: VP8

I would greatly appreciate your assistance in identifying and resolving this issue. Why is audio jitter present with more than 10 users, despite the server's capabilities? Are there specific configurations or optimizations I should apply?

Thank you in advance for your support!

[Ghazi TRIKI]

Hello,

Could you please share the model of the CPU used in your VM? Additionally, is this a cloud-based VM from a specific provider, or is it a self-hosted, self-virtualised environment?

Are all of your users based in the same country, or are they geographically spread out? Where exactly is the server located? Lastly, do you have an estimate of the latency to the server from your farthest user?

These details will help in better understanding the factors that may contribute to the audio jitter issue.

Thanks,

Ghazi

[Mohamad Sr]

CPU: AMD EPYC 7282 16-Core Processor (12 cores)
Server Type: Cloud-based VM from Contabo
User Distribution: Most users are from the same country, but not all. The server is located in the US (Central).

I don’t believe the issue is related to the server's specifications, as screen sharing and webcams function without any problems.