In today's world, where security breaches are all too common, the ability to secure your Lync Server 2013 deployment is critical. In particular, your key focus should be protecting external access to Lync, especially as federation capability has been further extended, allowing interaction with a wider range of systems. The Lync Edge role and its supporting components deliver the ability to communicate with billions of people worldwide. However, the possibility of communicating with that many people entails risk. When correctly configured, Lync's design will help you mitigate that risk.
Of course, its various core capabilities provide security. For example, Lync encrypts all its communications, both the signaling and the media, ...