Standards and Protocols
Any platform that needs to interoperate with other platforms will rely on standards, and a communications platform is no different in that respect. As with previous versions, Lync Server 2013 uses the Session Initiation Protocol (SIP) standard to provide its backbone, and it builds on that backbone by extending SIP to accommodate additional functionality.
Regardless of whether communication is conducted via the public telephone network using voice or via the Internet with other instant messaging products, you need to know the limitations of the protocols used and understand where interface gateways will be needed to extend beyond the edges of the Lync Server 2013 infrastructure. (Communication may include other ...