Here’s a little blurb on the features of Lync.  I think Call management/Lync is a HUGE opportunity for service providers.  Not a lot of companies host it today and organizations are not keen on deploying it in house.  Let me know if you are interested in learning more or hosting Lync today.   Love to hear about your offering.  

Lync can be used for license mobility and it there is an option for the SAL for SA option.  This is great if you have a multi-tenant (shared) infrastructure.  Below is directly from the SPUR.  New edition of the SPUR is at http://spur.microsoft.com/products.aspx

The available SAL types are:

• Lync Server 2013 Standard SAL (User / Device)

• Lync Server 2013 Enterprise SAL (User / Device)

• Lync Server 2013 Plus SAL (User / Device)

• Lync Server 2013 Enterprise Plus SAL (User / Device)

• Productivity Suite SAL (User only)

You do not need SALs for any user or device that accesses your instances of the server software without being directly or indirectly authenticated by Active Directory, or Lync Server.

Standard SAL

Each user or device for whom you obtain a Standard SAL or Productivity Suite SAL (user only) may use the following features of the server software.

• All Instant Messaging functionality

• All Presence functionality

• All Group Chat functionality

• All PC-to-PC computer audio and video functionality

Enterprise SAL

Each user or device for whom you obtain an Enterprise SAL or Productivity Suite SAL (user only) may use the following features of the server software.

• The features of the Standard SAL described above

• All Audio, Video, and Web Conferencing functionality

• All Desktop Sharing functionality

Plus SAL

Each user or device for whom you obtain a Plus SAL may use the following features of the server software.

• The features of the Standard SAL described above

• All Voice Telephony functionality

• All Call Management functionality

Enterprise Plus SAL

Each user or device for whom you obtain an Enterprise Plus SAL may use the following features of the server software.

• The features of the Standard SAL described above

• All Audio, Video, and Web Conferencing functionality

• All Desktop Sharing functionality

• All Voice Telephony functionality

• All Call Management functionality