Zscaler is a cloud security platform designed to scan data for potential threats. When installed on a presenter's computer, it reroutes both Webcast and Virtual Meeting Room (used by presenters) audio and video streams through the Zscaler security cloud before reaching the Webcast network. This can sometimes result in blocked video and audio or lead to call quality issues.
Since Webcast and Virtual Meeting Room connections don’t carry executable data, there is no need for Zscaler to scan them. To prevent interruptions, we recommend configuring Zscaler to bypass Webcast/VMR related traffic. If you're a Webcast presenter or participant with Zscaler installed, please contact your IT organization for assistance with this configuration.
For instructions on setting up Zscaler bypasses, visit: https://help.zscaler.com/z-app/best-practices-adding-bypasses-z-tunnel-2.0
To properly configure Zscaler, you can reference the complete list of network requirements : Technical requirements for using icastGo meeting rooms from a browser – icastGo User Help Center