Please use the below matrix to review compatibility of voice and IM support for different browsers.
|Voice and IM Support with the Skype Plugin
|IE 11 or higher, Edge (Chromium based)*
|IM Support Only
|Chrome, Firefox, Edge (Chromium based), Safari 12.0
|Voice and IM Support without the Skype Plugin
|Legacy Edge, Safari 11**
*To use the new Chromium based Edge browser from Microsoft with full voice functionality, you'll need to follow the steps in the article found here
**Apple has ended support of Microsoft's API and Skype for Business Plug-in in Safari 12.0 and later. Please see the following Microsoft KB for more information: Meetings clients
When to Contact CallTower Support
Contact CallTower Support if you've verified you're using the correct browser and still running into service issues.