On page Skype - openSUSE Wiki I am told that…
Skype is Proprietary Software and [NOT recommended]. So is there similar software that meets approval?
Jitsi is opensource and works well. I use it almost daily thanks to instances at work. Installing and configuring it in your own server can be a bit challenging. I tried a year ago or so and gave up. Have not checked since though, perhaps things are easier now.