This document discusses Lync and Skype connectivity. It provides information on the underlying technologies that enable connectivity between the platforms, including signaling and media protocols. It also outlines the key features and capabilities of connectivity versions 1 and 2, such as support for chat, audio, and video calling. There are diagrams illustrating the connectivity architectures and call flows. The document aims to help organizations understand how Lync and Skype can come together through these connectivity solutions.