Firefox browser extension to open "tel"-links with a IP-phone which provides a HTTP-API. For example Yealink, snom and others.

Go to about:addons in firefox, click on this extension and choose the "settings" tab. Set URL, username and password of your IP-phone. Now, if you click on a tel-Link on any website, it will call the number with your phone.

In the menu bar, you'll have a phone icon; when you click it, a page is opened on which you can see the status of your phone and where you can enter a number to call.

• Yealink