Licensing

It is very important that you understand the implications on installing application in the Citrix or Terminal Services (TS) environment. If you have doubts the best thing you can do is get your Microsoft and Citrix licensing representatives to clarify issues for you.

Don't take this lightly, making a mistake here can have severe legal consequences you personally and your company.

There are 3 terms that you should be familiar with:

Per user: This software is licensed to a group of nominated users and they can use it from any workstation. An option for Terminal Services licensing.
Per seat: This software is licensed to workstations regardless of how many people use it from that workstation. Used by MS Office.
Concurrent: This is just the number of simultaneous users. used by Citrix XenApp

You can't legally purchase per seat licenses, as is typical of Microsoft Office products, install it on Citrix servers and them limit it to a group of users. Per seat is defined by Microsoft as any workstation that can run the application whether or not they do.

Please note this article is simplified a bit as I have taken dozens of pages of licensing information and put highlights on a single page. Some details have been lost.

Citrix XenApp is licensed on a per concurrent user basis but Windows 2003 & 2008 Terminal Services is licensed on a per device OR per user basis but Terminal Services is not concurrent users but a total user basis. (Windows 2000 server has different licensing conditions to Win 2k3 or Win 2k8.)

Example 1: You have 300 people in your company who work 100 people per shift for 3 shifts per day and they all "hot desk" so there are only 100 computers. Only half the people run applications on Citrix at any one time so you have a concurrent load of 50 users but 100 seats. You need 50 Citrix licenses and 100 Terminal Services per device licenses. If you went for per user Terminal Services licenses then you would need 300 per user Terminal Services licenses as you have 300 users. Going for the per device TS licenses would be cheaper in this case.

Example 2: You have a small company of 10 people each of whom spends most of the day using applications on Citrix XenApp. Each user has a notebook computer and a desktop computer. They also connect via a VPN from customer sites or their home PC's. You will need 10 Citrix licenses as there are 10 people using it at the same time. In this example each user might access the Citrix server from 5 different computers so if you went for per device Terminal Services licenses you would need 50 licenses. If you buy per user Terminal Services licenses then you will only need 10 so per user is cheaper in this case.

Note that the per device licensing is monitored and strictly enforced at the Terminal Services licensing server. You will be denied a logon once you pass your license limit. The per user licensing does not have monitoring or enforcement built into the software but you still have legal liability if you are using more licenses than you own.

OTHER LICENSING

When you set up Citrix XenApp on Windows 2003 or 2008 server you will require the following licenses:

A Windows 2003 or 2008 server license - 1 license per server.
Citrix licensing is done on a per concurrent user connection basis (the server licenses are free.)
A Microsoft Terminal Services CAL that are either Per User or Per device.
A Windows CAL for every workstation that connects.
The applications have to be licensed for users but every vendor has a different licensing scheme. They are significantly different and it is critically important you understand what your license agreement requires of you. (The Microsoft Office licensing is usually per seat and can have unexpected implications - more on this shortly.)

While you are designing your Citrix servers need to have an exchange in writing with your application vendor to confirm your understanding of the licensing position. Such as exchange may be a life saver in court one day. Keep your correspondence and file it so it can be found after you have been head hunted to a better job.

BIG TRAP FOR YOUNG PLAYERS

Microsoft Office is usually licensed on a per seat basis. This is not remarkable to anyone, you need a license for every workstation that has it installed, whether you use it or not. So how does Microsoft view per seat licensing if none of your workstations have the application installed and it is only installed on your Citrix XenApp servers?

Every terminal that CAN run it must have an Office license. In Example 1 (above) there were 300 people and 100 computers so you would only need 100 MS Office licenses - no brainer.

In Example 2 (above) there were 10 people but 50 machines in use. You will need 50 Office licenses. Now you know why the Microsoft Enterprise licensing agreement has a 'take home' Office license at a vastly reduced price. Hopefully your client sites will have Office already installed and will be covered.

Example 3: You have 10 computers in the management area, 20 computers for admin staff and 80 Wyse terminals in your call centre. The call centre workers only use 1 database application that was written in-house. All users in the management area use M$ Office Standard edition on their Windows XP computers. 2 users use M$ Project that is installed on the Citrix XenApp server but the application is only published to these 2 users. How many MS Project licenses do you need?

You need 110 MS Project licenses because there are 110 terminals that CAN run M$ Project. Remember Office is licensed on a per seat not a per user basis.

One option is to use a Citrix policy to limit the access to a particular server to workstations on a range of IP addresses. If you set your workstations that a licensed to use a particular product to know fixed IP addresses and then gave only these workstations access to the server with your sper seat product on it then this would appear to meet the per seat licensing requirements. (This server could be a VMware or XenServer server.)

An easier question about Example 3: How many Office Standard edition licenses will you need if you install Office Standard edition on the Citrix server? Answer: 100. Each of the Windows XP already has an Office license so do not need a second one. Because you have 20 computers and 80 Wyse terminals in the call centre that could now run Office you need a license for each of them, even if the applications are not published to the normal users of these terminals - the point is the terminals CAN now run Office. The exception is if you use something like AppSence or Citrix Policies to prevent anyone getting on to M$ Office from the Call Centre computers and Wyse terminals.

Microsoft can be flexible about the per seat or per user issues but you have to talk to them first. Contact your Microsoft licensing representative for clarification and possible exceptions (or go read the Star Office license agreement.)

ADOBE ACROBAT PDF WRITER

The Acrobat PDF Creator is licensed on a per user basis plus you buy one license for the server and one for each user then limit access to the "printer" to an Active Directory User group who has licenses. I find this a very reasonable approach.

However, there are a couple of really good Open Source products called CutePDF available from http://www.cutepdf.com/ and PDFCreator available from www.pdfforge.org that are totally free and works really well with Citrix. Try them before spending your money on a commercial .pdf writing product.

The Adobe Acrobat reader is free but later versions have problems with leaving locked files in users' profiles. I recommend you install Foxit to read .pdf files.

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