The interesting concept is that Skype For Business can be used in addition to Lync provided that the Lync servers have the Skype Integration that will support the usage of Skype. The thing is, you may have to log out and then restart the client app if you want to switch in between those two. This year, a new version called Skype for Business Server 2015 was recently released that the servers running Lync Server can be upgraded to. From what I heard, various components are inside the Azure and Office 365 respectively and again, the communication still works the same way and somehow, Microsoft Lync is like one of the popular choices in comparison to some Cisco service that works the same way except that Microsofy Lync has some components that supersede the ones that service from Cisco uses.
The communication can be done from the phone, the tablet and computer running Lync or Skype for Business and like Skype for consumers, Skype for Business allows you to communicate with those who don't use their Skype organizational accounts but I suggest that you do this kind of communication on your personal device where you login to Skype through organizational account on it. Depending on the network performance, there may or may not be some lag when doing that kind of phone call.
