Enabling Public IM Connectivity (PIC)
Lync Server public IM connectivity (PIC) enables users to communicate with public instant messaging (IM) networks such as MSN, AOL, and Skype. It operates in a similar fashion to federation in that it uses the same ports and topology, but it has a slightly different set of steps to configure. The main difference is that public IM connectivity must be configured through the organization’s licensing site with Microsoft. The public IM providers do not use the SRV record for open federation and instead require these manual steps to provision the initial connectivity.
Yahoo! Public IM connectivity was previously offered as a per-user subscription license, but the service has been disabled as of December ...