It doesn’t just magically work though, the Lync administrator needs to apply with Microsoft for the Skype to Lync federation to occur. It’s a fairly easy process to request, assuming that you’ve already got standard federation up and running with edge servers. This was launched 29th May 2013 as per this post
Microsoft Lync can now federate to Skype! This means that users can communicate between each system, which is awesome.
