Reoccuring questions on Cals


Jun 28, 2004
This question has been asked over and over again.

So when and where do you need to have CALs?


You need a Cal license for each computer you want to connect to a domain controller.

If you have a primary and a secondary domain controller, do you need to have only enough cals for one Server OS, or for 50 users do you need 50 Cals per Server OS? Does a CAL port to all the servers in the domain or is it locked and usable for only that one machine?

How is this cost effective?

If you have a Domain Controller DNS/DHCP Server, a file server, a exchange server which machine needs cals?
If you have 50 users, how many cals do you need in this instance?
If you have a V-Hypervisor 2008 Server, do you need cals for that?
Are cals treated differently in different server editions?


[H]F Junkie
Jun 17, 2003
First off, CAL is a generic term and applies to different services. For instance, 1 Server CAL ( as in, 2003/2008 Client Access License ) is needed per device ( or user, but I typically go with device. Varies depending on the workload ) connecting to your servers, but it is organizational wide. So if you have 2000 devices, 20 servers, you only need 2000 device cals. These cals cover file/print/directory services ( aka, incidentals ).

Terminal Service CALs are different; those are in a pool and are metered out ( depending on device/user ).

SQL CALs are different again in that you have to be aware of multiplexing ( as in, any device where data is eventually saved to an MSSQL database needs it's own cal, regardless of the transformation in goes through to get there ).

Unless you are on a SA contract ( Software Assurance ), then you are typically buying the latest CALs ( so right now, you'd be buying 2008 Server CALs ). These will typically ( not always ) cover downgrade rights, so you can use them on 2003 as well. This is one of the areas where SA shines; Get your CALs under SA, and you always have the latest that you need. Especially useful with Server/TS cals, but SQL as well.

Oh, keep in mind different services also offer differing licensing models. So while you can worry about CALs with SQL, you have the option to go with socket licenses ( along with 2 other models, I think. It's been a while ).

CLIFF NOTES: This is a rat's nest of complexity, and really requires an expert. I've worked with CDW in the past, to great success. They have MS licensing experts on staff that you can abuse...erm..."utilize".