Group Calling Topology

Group calls implement a hybrid topology to achieve the participant scale of the group rooms, while retaining our enhanced call features.

This hybrid topology uses:

• A star topology using a media server (SFU) for the transfer of audio and video media. Participants in the call establish a single WebRTC connection to the media server, and publish their audio/video streams for other participants to consume, and download other participants audio/video.
• A mesh topology (P2P) for exchange of application data (such as resources information/file transfer/chat/etc). Each participant creates this connection to each other connection, but no audio/video media is sent.

Security

Group calls maintain the high security levels healthdirect Video Call already employ. Group rooms use a minimum of AES 128 bit encryption up to 256 bit. For more information on privacy and security, click here.

Bandwidth 

For healthdirect Video Call group rooms, the recommended minimum requirements for a group call are as follows:

• Upload: A minimum of 350kbps upstream bandwidth for sending audio/video
• Download: A minimum of 350kbps downstream bandwidth for each other participant in the call for receiving audio/video from the media server, using the following formula:
  • Downstream bandwidth required = (n-1) * 350 (where n is the number of participants in the call)
  • e.g. Downstream bandwidth requirements for a call for 10 participants
    • 9 * 350kbps = 3150kbps (~3.1 Mbps)

Please note, adding content such as sharing will add an additional stream of 350kbps for each participant. 

Go to Group Calls in the Waiting Area page