OCS 2007 Licensing

First of all, OCS 2007 has two options for server license:

1. Standard Server
2. Enterprise Server

Regarding clients:

1. OCS 2007 has a Standard CAL and an Enterprise CAL. At minimum, a Standard CAL is required for each user and the OCS Enterprise CAL is an additive CAL, like the Exchange Server Enterprise CAL.
2. In addition, Communicator licensing is not included in the CAL license or Server licenses for OCS 2007 so a Communication license is required for each user.
3. The feature-content offered by the Communicator application is handled by the Standard CAL. Other OCS 2007 features require an Enterprise CAL.

So to summarize, you must license the Server software, you must license access to the server for each user, and you must license the primary user interface to the server software.

Server pricing:

1. Office Communications Server 2007 Standard Edition         $699
2. Office Communications Server 2007 Enterprise Edition      $3,999

OCS 2007 Standard contains most of the features of OCS 2007 Enterprise, but is limited in terms of storage space, clustering, and highly-available option support. Thus Standard Edition is targeted at companies who can "afford downtime".

Client pricing:

1. Office Communicator 2007           $34
2. Standard CAL                              $31
3. Enterprise CAL                            $139

Significant features provided by each CAL type are:

Hope all this info help (I tried simplifying it as I could :))