Frequently Asked Questions
1. Can ProCONF provide a better performance evaluation compared to other media servers?
--> The ProCONF backend (Jitsi) uses the Selective Forwarding Unit (SFU) architecture which allows lower operation cost and performance management. With a server machine equipped with a quad-core Intel ® Xeon® E5-1620 v2 @ 3.70GHz CPU, the following result can be obtained.
| Parameter | Value |
|---|---|
| Number of audio streams | 1056 |
| Number of video streams | 1056 |
| Bandwidth usage | 550 Mbps |
| CPU utilization | 20% |
The above data is equivalent to 528 one-to-one conferences, 176 3-person conferences or 53 conferences with 5 people. For more details, please refer to https://jitsi.org/jitsi-videobridge-performance-evaluation/
It is worth noting that the above numbers consume only 20% of the CPU, hence promising there that is room to accommodate more streams. Conversely, for users looking for a lower configuration setup will also be able to support sufficient number of streams.
As of April 2024, Jitsi has enabled a new feature SSRC Rewriting that improves the system performance for larger calls. This feature helps reduce the overall load on the system by reducing the number of signaling messages that get exchanged during a large call, thus optimizing the data transmission for 'n' number of users. Hence, irrespective of the number of users in the call, the amount of data transmission will be limited. This mechanism makes Jitsi stand out from other media servers.
Read the below link to find out more about SSRC Rewriting.
https://jitsi.org/blog/improving-performance-on-very-large-calls-introducing-ssrc-rewriting/
2. How can I reduce the video quality to improve my bandwidth utilization?
--> ProCONF allows you to set the required video resolution as a system-wide setting. Default set to 'High', the user can change to 'Medium' or 'Low' quality in order to save bandwidth.
You can change this value under the Admin Dashboard -> Performance Tuning -> Video Quality option.
Following are the available Video Quality options and their corresponding resolutions
| Quality | Resolution |
|---|---|
| High | 1024 x 720 |
| Medium | 640 x 480 |
| Low | 320 x 240 |
3. Can I change the video codec to a preferred one?
--> Yes, ProCONF allows a way to set the preferred video codec on the client endpoint. While the preference can be applied as a system-wide setting, the user can also decide the preferred codec for each meeting by passing it as an option while creating the room.
The supported video codecs are [ 'AV1', 'VP9', 'VP8', 'H264' ] for desktop endpoints and [ 'VP8', 'H264', 'VP9' ] for mobile endpoints. While 'H264' provides the best video quality, 'AV1' can be chosen for desktop clients to reduce bandwidth usage.
You can set your preferred codec under Admin Dashboard -> Performance Tuning -> Preferred Codec
4. Can I optimize my bandwidth usage by limiting the number of videos I receive in a large meeting?
--> Yes, you can do from the Admin Dashboard -> Performance Tuning -> Active video streams
This property specifies the number of videos that are to be delivered. Default value is set to -1 for unlimited or all available videos. However, one can configure this value to fetch the latest 'n' number of videos active in a call, thus allowing to optimize the bandwidth.