Microsoft Skype for Business--formerly known as Microsoft Lync, and Microsoft Office Communicator before that--is the Instant Messaging, Presence, and Voice Call service from Microsoft. The network traffic looks very different from Microsoft Skype, but eventually the two may merge. This application uses SIP-TLS, and LDAPS over TCP ports 5060-5062.

This SonicWALL signature identifies legitimate Microsoft Skype for Business traffic.