Lync Server identity validation mechanisms are able to manage different kinds of personas, including authentication for a device, server, and user. The previously mentioned identities can require access to Lync in an on-premises datacenter, in a public Cloud, or in a hybrid Cloud scenario. The shift from Lync deployments that span over a corporate network to more complex setups required identity verification instruments to be adequate. Windows 2012, Windows 2012 R2, Azure, and Office 365 support a number of solutions (such as DirSync and identity federation) that add flexibility to our design.
Lync Server 2013 is able to accept both Cloud identities (stored in the Cloud) and federated identities (stored and managed on-premises). Talking about Lync Server 2013 on-premises, we have support for the following different user authentication protocols: