Meeting with about 1000 participants

Is it possible to continue a meeting with 1000 participants. Only the host share video. Others can ask question during the meeting. Is this possible

Scaling up to 1000 participants that interact is hard. I will go trough some of the bottlenecks that you will experience.


Client computer bottleneck
Jitsi meet work out of the box with up to about 15 participants. After that you will start to run into bottlenecks for users with slow computers that the user-interface redraw itself too much and consume 100% cpu.
This can be solved by profiling using the chrome performance monitor and disable all things that consume CPU time.

For example audio level monitoring that render the blue dots when someone talk trigger GUI updates. With many users these GUI updates will cause the client web-browser to redraw too frequently that will cause the user to have a bad audio experience due to missed audio updates. The solution is to simply disable the AudioLevels monitoring.
disableAudioLevels: true,

On the left only 10% CPU when audio levels are disabled. On the right 100% CPU time when audio levels are enabled due to frequent audioLevelReport processing and GUI re-layout.

Server bandwidth bottleneck
Sending video to 1000 participants require high server bandwidth.
This can be solved by using the new OCTO feature that use several video bridges to serve one conference room.
You can also reduce the video quality in order to lower bandwidth.
With only one speaker and 1000 viewers, bandwith for one server is quickly consumed.
720p + audio require ~ 3mb/s * 1000 = 3 Gigabit/s
360p + audio require ~ 1mb/s * 1000 = 1 Gigabit/s
240p + audio require ~ 0.2mb/s * 1000 = 200 Megabit/s

Most sucessfull jitsi meeting only have about 30 participants using jitsi meet directly and then stream using jibri to google for all 1000+ passive viewers.

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Thanks for that hint! We just made that change (disabled the audio levels) and I see a raise from 0% idle (9 user conference) to around 70% idle (11 user conference). And the users didn’t notice the missing audio levels.

For now, we will keep them off.

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With many users you will cut 70% of the combined energy bill :wink: by adding this option
Assuming all users are using a laptop that consume 50W at 100% CPU
1000 users * 50W = 50kW!
by adding this
disableAudioLevels: true,
option power get reduced by 35kW for all the users combined.

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That was a really excellent suggestion. This is currently the most heard complaint that we have on our installation: Client resource usage… We will now also bill it as a “green” video config solution :wink:

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