I have read some articles about CAL and I know when I should buy User CAL and when I should buy Device CAL. However I don't know under what condition I should need CAL. According to Wikipedia that's what is written: In Per-User mode, a CAL is purchased to allow one user to connect to the server software. Any user can connect, but only one user may use a given CAL at any given time. Does this limited to application like remote desktop, Active Directory only? Is other service such as shared folder, FTP, in-house program also need CAL when they are running on the server and allow user to connect? Another question is when I set up a web server, in which the number of user or number of device connected to the server is unknown, it really doesn't make any sense in having user CAL or device CAL. Is there any other license for such purpose? Thanks in advance. =)

HI Cal is required in case you are using Terminal Services ,SQL,Exchange etc. For Web server you don't need any licenses for the users. If you are sharing folders in your OS , again you don't need it but if it is shared on SQL server then Cal is required( for SQL) . Cal is required in MS-Project too. So basically wherever you are distributing your service you require to buy cal .

Thanks for your information. I am not quite sure what you mean by "if it is shared on SQL server". As far as I know SQL server is an application but not an OS. How am I able to share a folder on SQL server? I still don't have the clear cut line in deciding whether a CAL is needed or not. What exactly the criteria in making such decision? From what you have explained, it seems that FTP or in-house program running on the server does not need CAL as well. Am I correct? Can I actually make a conclusion that: Non-Microsoft component does not require CAL ?

Hello, you need CAls for machines or users connecting to a server. And additional you need RD/TS CALs if users/computers should be used to connect to a RD/TS server session. Beside that different CALs exist for SQL or Exchange, just to mention 2.Best regards Meinolf Weber Disclaimer: This posting is provided "AS IS" with no warranties or guarantees , and confers no rights.

you need CAls for machines or users connecting to a server. I am actually very confused by the above statement. vinit pandey have mentioned that there is no license needed for a web server and file sharing (assume he is correct). The above statement should be part of the story but is not the whole picture. I would like to know in what are the exception to the above statement (Web server is one, file sharing is another) and how do we judge if some services (EG. FTP) falls under the exception.

Hi I am sorry for not making my statement clear. I know that SQL is not an OS. I meant that if you have used SQL as your database server than you need to buy CAL for it.You can keep your files on SQL ..Right. Now what conclusion we can draw is that for those application which we are distributing in the environment needs CAl. For Ftp you don't need to buy any cal becouse you are not distributing any service or application,you are just transfering your files. Yes, Cal is not required for Non-MS Application. For those application there vendors will have there own licensing scheme .

Thanks! I guess what you pointed out make sense to me. Distributing services from MS need CAL but not distributing files. =)

the way I usually explain it, is like this: "if the service requires authentication, then you need a CAL". you *do* need CAL's for file/print services, SQL, RDS (and they are different CAL's for each). anonymous web users who are not authenticating to your IIS *do not* need a CAL. it's tricky. there is lots of information on the MS Volume Licensing website for the topic, and your reseller is there to help you. http://www.microsoft.com/licensing/about-licensing/product-licensing-faq.aspx#tab=4 Don

Thanks Don. I think what you said is more reasonable! But do you mean file sharing also need CAL?