Lync – Skype Connectivity allows Skype users and Lync users to add each other as contacts, exchange instant messages and make audio calls. When a Skype user adds a Lync user, a Skype user will create a contact in Skype containing the session initiation protocol (SIP) uniform resource identifier (URI) of the Lync user. Conversely, when a Lync user adds a Skype contact, the Lync user will create a contact in Lync that will contain the Microsoft Account (MSA) of the Skype user, and not the Skype user name.

 

What is an MSA? Skype users must sign in to Skype with a Microsoft account (previously called Windows Live ID) in order to communicate with Lync contacts.  A Microsoft account is the combination of an email address and a password that you can also use to sign in to services like SkyDrive, Windows Phone, Xbox LIVE, and Outlook.com (and previously Hotmail or Messenger).  If you use an email address and password to sign in to these or other services, you already have a Microsoft account.  For information on creating a Microsoft Account, see Create a Microsoft Account. You can merge your existing Skype account with your Microsoft account for single sign-on across a variety of applications and services.