How build NAC?

[titans2011]

Hi all.
I have a few questions. I am a student. I'm writing a diploma. In its work, using equipment Cisco. I passed the level of CCNA. But I really urgently need to do a layout for my thesis work.
Raw data:
Cisco Switch 3550, it set up VLAN
Router 2600XM, makes routing between VLAN
I have the Cisco NAC appliance running in VMware. There is a server and manager. Version 4.1.
Questions:
If you configure a server manager, can run the server independently, without access to a manager?
Does this technology Encrypt packets ?
It was my first encounter with this technology. Nobody is helping me. I need that would be on the client computer to install a program that checks their computer for the updated operating system. For me it is difficult to follow the material Cisco Guid (a lot of material, an urgent need to make a working model), can you give me a link to build such a network (server, manager, and if need to Cisco), or briefly describe how to do this?
Thanks in advance.

[edwjames]

So if you need any other help...

[titans2011]

Well. I set up a network so as you said, I understood all the points, trying to connect to the Web site.
I am interested in this question: what is the latest version of NAC? What's new in this version: in comparison with the old?

[edwjames]

The latest version of NAC appliance is 4.8.2.

The latest version of the NAC agent is nacagentsetup-win-4.8.2.1.

[titans2011]

Well. I configure CAS and CAM from link in your first answer. I think this is not full guide, because i found link in CAM, where i need add CAS. After added, server report that he look CAS, And i test to client connect to CAS. But i not have any answer from CAS, and look in log that erorr. What' i need to do?