Lync Server 2013 supports the use of licensed public instant messaging (IM) connectivity providers, as well as the use of eXtensible Messaging and Presence Protocol (XMPP) to implement a special type of federation that enables a Lync Server to access configured XMPP domain partners by using the Lync 2013 client.
The currently supported public instant messaging connectivity partners are:
For communications with Windows Live users, Lync Server 2013 supports peer-to-peer IM and audio and video calls. For communications with AOL and Yahoo!, Lync Server 2013 supports peer-to-peer IM. A separate license may be required.
As of September 1st, 2012, the Microsoft Lync Public IM Connectivity User Subscription License (“PIC USL”) is no longer available for purchase for new or renewing agreements. Customers with active licenses will be able to continue to federate with Yahoo! Messenger until the service shut down date. An end of life date of June 2014 for AOL and Yahoo! has been announced. For details, see Support for Public Instant Messenger Connectivity.
The PIC USL is a per-user per-month subscription license that is required for Lync Server or Office Communications Server to federate with Yahoo! Messenger. Microsoft’s ability to provide this service has been contingent upon support from Yahoo!, the underlying agreement for which is winding down.
More than ever, Lync is a powerful tool for connecting across organizations and with individuals around the world. Federation with Windows Live Messenger requires no additional user/device licenses beyond the Lync Standard CAL. Skype federation will be added to this list, enabling Lync users to reach hundreds of millions of people with IM and voice.