Disclaimer: the new version of Lync Server 2013, Skype for Business (SfB) Server 2015, has been released a few weeks ago. Licensing model is the same you had for Lync Server, with companies paying only Front End servers (i.e. the ones hosting user accounts and the core services for your infrastructure). SfB contains some new features, including support for Back End availability based on AlwaysOn groups. I will write a dedicated post asap.
The costs related to Microsoft Lync are something that I have talked about more than once but this is the first time I try to summarize information in a single document. I will limit my reflections to on-premises organizations, because as I am writing, Lync Online has no serious support for Enterprise Voice (i.e. VOIP) and this makes the Cloud version of Lync less flexible (and somewhat less interesting) than the more traditional, corporate deployment.
A starting point for all cost-related considerations is to understand which kind of service we need. Lync Server 2013 supports solutions ranging from a single, all-in-one box (with a mandatory Office Web Apps server required to share PowerPoint presentations) to hundreds of servers geographically dispersed. Let us list some parameters.
The first parameter you have to establish is the number of users that will require Lync services. Lync 2013 Standard Edition (S.E.), the aforementioned single box, is tested to support up to 5,000 users. Obviously, before you reach the 4,999th Lync enabled account, it could be a good idea to add a second Front End (the server that delivers core services to the users) or consider a Lync Enterprise Edition (E.E.) solution (more details on the two editions of Lync Server 2013 are explained in the next paragraph)
Second parameter will be the required level of availability. If we deem service continuity as required for any of the Lync features (especially if we are going to use Lync as our VOIP system), it should be in a high availability deployment. Lync pools support a feature called Pool Pairing, if we have at least a couple of Lync 2013 S.E. Front End servers in our infrastructure.
It is not an H.A. solution, but adds resiliency to the solution and it grants some degree of survivability to the voice users. In a paired pool, using a series of scripts, we are also able to fail-over and fail-back Lync users, restoring full functionality for them. A highly available solution requires the E.E. of Lync Server 2013.
Although there is no difference in the cost of licenses between S.E and E.E., to use Enterprise Edition you must have at least pool of three Front Ends connected to a separate SQL Server database (whereas S.E. uses a collocated SQL Server express at no additional cost).
A dedicated SQL infrastructure would also require a continuity solution, like clustering or mirroring. A well-known rule of thumb is if we need to provide high availability, then we need to remove any potential Single Point of Failure in the design.
Small, remote offices might also require (at least) voice survivability. For such a scenario, we have a dedicated implementation of Lync Server 2013, the Survivable Branch Appliances (SBA); these are less expensive than a full-blown Lync front-end server.
Note: SQL licensing for Lync Server 2013 has been deep dived in a good post from fellow MVP Thomas Poett in his blog Lync Server 2013: Lync Backend SQL Server Licensing http://lyncuc.blogspot.it/2014/01/lync-server-2013-lync-backend-sql.html
Availability requirements have an impact also on point 3 and 5 of this list.
Lync requires some additional servers that have no additional cost from the Lync server licensing point of view but that add costs to acquire the base Operating System, hardware and so on.
Note: Every Lync, Office Web Apps, SQL database and reverse proxy (if you are going to use a solution based on Windows Server) will require a license for the Operating System. You could use virtualization rights (Licensing for Virtual Environments https://www.microsoft.com/licensing/about-licensing/virtualization.aspx ) to keep costs down, but this aspect is to be included in the list
For the following point, I will quote my free e-book Microsoft Lync Server 2013: Basic Administration (http://gallery.technet.microsoft.com/office/Lync-Server-2013-Basic-0a86824d )
Lync requires a CAL (Client Access License) for each user or machine that logs on to the server. CALs are of three types and each one is entitled to the use of a part of the features. Access to premium functionality is determined by adoption of the Standard CAL and then you have to add supplemental CALS, an Enterprise CAL and, for some additional features, a third license called Plus CAL (you may think to Enterprise CAL and Plus CAL as supplemental to the Standard CAL).
There are a couple of entries in the bill of materials not directly related to Lync, but that we have to consider anyway:
Now, as it is easy to understand from the previous list, there is no right answer to the starting question. I will try to focus a few points:
1.High Availability will raise the costs, as usual
2.Using Lync Enterprise Voice will add license and infrastructure costs (as well as making H.A. almost mandatory)
3.The number of users and their level of access to Lync’s features will impact budget both for the deployment sizing and for the needed client licenses
4.The bulk part of the expenditure items related to a Lync deployment are not related to Lync server licensing, but to the other voices we have seen
Alessio Giombini contributed to this review.