Microsoft’s Lync Licensing
Microsoft Lync is the latest edition (brand name) of MS Office Communications server products. As most of you may already know, Lync can be deployed locally within an organization (on-premise) or it can be purchased as a service from either Microsoft themselves or a third-party managed service provider (MSP). Briefly, to deploy Lync in your organization you need a license for each Lync Server 2010 instance and a Client Access License (CAL) for each user and device. Standalone and enterprise licensing models exist and this is similar to the other major products delivered by Microsoft. Conversely, if you go for a hosted solution then you would face a subscription licensing model which in my opinion is much simpler to handle!
The Server/CAL licensing model for on-premise implementations incorporates servers, clients and external connector components. Therefore, you need a license for each:
Server instance you will be running, whether Standard or Enterprise Servers
User accessing the servers, known as CALs and we find three types
Standard CAL – enables standard features for a user such as, IM and video & audio conferencing between internal computers
Enterprise CAL – enables enterprise features such as, extended conferencing features – External & Web
Plus CAL – enables plus features such as, VoIP features
To enable all features, a user must be licensed with all three CALs
External Connector, which is an external entity (travelling employee, business partner, etc.) connecting to your servers. There are three External Connectors which are Standard, Enterprise and Plus. External users' licenses can be purchased as CALs or ECs:
CAL – a license for each external user
EC – a license for each server (can have multiple instances) that will be accessed by an unlimited number of external users
Users' CALs (as explained in point 2