[gourou]

I thought Skype calls used to be P2P

[verytrivial]

The Skype developers tried to let us know many many years ago: https://www.flickr.com/photos/fishywang/318591561

[Phlarp]

Used to be, yes.

[Alupis]

Only sometimes, when it couldn't make a great connection between the two callers.

Now, from my understanding, Microsoft has re-worked Skype to always connect via their Skype servers (as the middle man).