In this topic:

About Click-to-Call

You can join a StarLeaf meeting within a web browser using Click-to-Call, even if you do not have video meeting equipment. Video calling within a browser is sometimes known as WebRTC (Web Real-Time Communication).

Click-to-Call allows you to:

  • join a StarLeaf meeting from a web browser
  • call any StarLeaf endpoint from a web browser. This includes StarLeaf room systems, StarLeaf app, and any H.323 or SIP endpoint that is registered to the StarLeaf platform
  • create a link in your email signature which launches a browser ready to call you (if you have a StarLeaf account)

You can also create links to allow video calls to anyone in your organization from your web sites or applications. For more information, go to Browser Click-to-Call links.


Click-to-Call is only supported on Windows and macOS devices.

The following StarLeaf meeting features are not supported in browsers:

  • In-meeting chat
  • Raise hand in Spotlight meetings
  • Participant management

For a richer meeting experience, download StarLeaf to your desktop or mobile.

Supported browsers for Click-to-Call

For best support and compatibility, StarLeaf recommends using Google Chrome or Mozilla Firefox.


You do not need an add-in to use Click-to-Call, but you need to install the Screen Share for StarLeaf Click-to-Call extension if you want to share your screen while in a meeting. StarLeaf prompts you to add this extension when you want to share your screen.

Click Add to Chrome to be directed to the Chrome store. You can also find the add-in in the Chrome store here .


You can use Click-to-Call, and share your screen using the latest version of Mozilla Firefox.

Internet Explorer

Starting 3rd April 2021 (and possibly earlier for pre-release customers), StarLeaf will no longer support joining meetings through the browser Internet Explorer 11. If you attempt to join a StarLeaf meeting using Internet Explorer 11, you will be advised that it is not possible and prompted to instead use Google Chrome, Mozilla Firefox, or Microsoft Edge 79 or higher.

You can continue to access the StarLeaf Portal using Internet Explorer 11.


Safari is not supported.

Microsoft Edge

Microsoft Edge 79 or higher is supported.

TCP media support

StarLeaf browser based video calling does not require UDP ports to be open on your firewall, however, StarLeaf calls prefer to use UDP if possible because of superior call quality.

The use of TCP ports allows:

  • successful browser-based calling even where there is a corporate firewall that is configured to block UDP traffic
  • better performance where there is limited bandwidth

Firefox users must have access to UDP as, currently, Firefox browser calling does not work with TCP port 443.

To find more information about ports used by Click-to-Call, refer to Firewall configuration for StarLeaf endpoints.

Dynamic bandwidth support

StarLeaf Click-to-Call uses dynamic bandwidth. This effectively prevents video browser calls from overusing your Internet connection. Where you have low or fluctuating bandwidth, Click-to-Call automatically adjusts bandwidth use to avoid packet loss.

Dynamic bandwidth support also means that where there are good network conditions with high bandwidth availability, Click-to-Call will scale up resolution and provide a much better video experience.

The dynamic bandwidth algorithm used by Click-to-Call is designed by Google, and this is implemented in all browsers we support. For more information about that algorithm, refer to A Google Congestion Control Algorithm for Real-Time Communication on the WWW .

Proxy support

Click-to-Call supports connections through proxies that support the use of HTTP CONNECT on port 443. StarLeaf uses HTTP CONNECT to open an end-to-end TCP connection between the browser and the StarLeaf Border Controller. Click-to-Call will use the proxy settings that are configured in the user’s browser settings.

The proxy must allow connections to <subdomain>