StarLeaf Cloud allows for video calling to take place within a web browser. We call this Click-to-Call. Video calling within a browser is sometimes known as WebRTC (Web Real-Time Communication).

People who want to join a StarLeaf conference (and who do not have their own video equipment) can use Click-to-Call to do so.

  • Anyone can now directly dial in to a StarLeaf conference from their web browser, simply by clicking a link
  • Anyone can now directly call any StarLeaf Cloud endpoint from their web browser. This includes StarLeaf room systems, StarLeaf desktops, StarLeaf Breeze, and any H.323 or SIP endpoint that is registered to the StarLeaf Cloud

Guest invites now include a link to call the person who sent the invite point-to-point from a web browser.

If you are a StarLeaf user, you can now include a link in your email signature (or elsewhere) that launches a browser ready to call you.

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

Browser support for Click-to-Call

To use Click-to-Call, video callers need at least:

  • Chrome 46
  • Safari 9 (requires plugin)
  • Internet Explorer 11 (requires plugin)
  • Firefox 45 (not recommended)

For best support and compatibility, StarLeaf recommends using Chrome for Click-to-call. StarLeaf recommends that you do not use Firefox for Click-to-Call.

Browsers running on iOS (iPhone and iPad) do not support any WebRTC. Therefore, you cannot use Click-to-Call on these devices.

Chrome

Chrome users do not need a plugin to use Click-to-Call, but they need a to install an extension if they will share their screens whilst using Click-to-Call.

To be able to share your screen from Chrome, you will be prompted to use the Screen Share for StarLeaf Click-to-Call extension. Chrome users can find the plugin here: https://chrome.google.com/webstore/detail/screen-share-for-starleaf/dliccfbpegdcmlflaidhhnloeofgdnce .

Internet Explorer

Internet Explorer users will be prompted by their browser to download the StarLeafBrowserPlugin when they load the Click-to-Call page in their browser. This enables the browser to use Click-to-Call and also use screen share.

Firefox

Firefox users do not need a plugin to use Click-to-Call, but they need a to install an extension if they will share their screens whilst using Click-to-Call.

To be able to share your screen from Firefox, you will be prompted to use the Screen Share for StarLeaf Click-to-Call extension. Firefox users can find the plugin here: https://addons.mozilla.org/en-GB/firefox/addon/screenshare-starleaf-c2c/.

Safari

Safari users will be prompted by their browser to download the StarLeafBrowserPlugin when they load the Click-to-Call page in their browser. This enables the browser to use Click-to-Call and also use screen share.

If you are using the Safari browser on OSX, you may encounter issues with the Mac feature AppNap. This feature puts apps to sleep if they are running in the background and aren’t visible to you, and includes individual Safari tabs. If you minimize a window while Click-to-Call is active, the call is unable to respond until you bring it to the foreground again.

This does not prevent you from using Click-to-Call but may cause difficulties in screen sharing situations where other participants in the call are sharing content. When AppNap has put the tab with the call to sleep, the request to start a screen share times out and you are dropped from the call. StarLeaf recommends that if you are using Click-to-Call in Safari and on OSX, you keep the Safari tab with the call in the foreground if at all possible.

As an alternative, you can use the Chrome browser or disable AppNap. If you choose to disable the AppNap feature, be aware that your battery life will be effected.

Content share for browser-based video calling

Users of StarLeaf Click-to-Call browser video calling can share their screen with the person or conference at the other end of the call.

The picture below shows a browser-based call with shared content.

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 that provides 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.

Encryption for browser Click-to-Call (WebRTC) calls

For StarLeaf browser-based (WebRTC) calling, the call signaling uses TLS authentication and encryption. The media stream is encrypted using SRTP. During call signaling, the StarLeaf Cloud shares a DTLS fingerprint using TLS signaling. This fingerprint is used to set up a secure DTLS connection for the media.