Windows Server 2008中的终端服务功能，允许你通过任意类型网络使用大范围的设备，在Windows服务器上远程执行应用程序。一个运行终端服务的服务器可称为终端服务器。
终端服务授权需求
Windows服务器授权
Windows Server 2008授权模型需要每个服务器软件的运行实例提供一个服务器授权。终端服务功能已经包含在Windows服务器授权中。
Windows 服务器客户端访问授权
除了服务器授权外，同时还需要Windows服务器客户端访问授权（CAL），如果你希望使用Windows Server软件中的终端服务功能，你还需要一个增量的终端服务客户端访问授权，每个用户和设备都需要提供终端服务CAL。
可用的终端服务CALs
以下的终端服务器客户端访问授权可用：
终端服务设备CAL允许一个设备（被任意用户使用）访问你任意服务器的终端服务功能。
终端服务用户CAL允许一个用户（使用任意设备）访问你任意服务器的终端服务功能
终端服务外部接入者授权允许多个外部用户访问单一终端服务器，如果有多个外部接入者访问多个服务器，则你需要购买更多Windows Server外部接入者授权，或使用为终端服务器外部接入者提供的APP-V.
服务提供商授权协议(SPLA)适用于提供终端服务的服务提供商.
你可以在服务器软件上同时使用终端服务设备CAL和用户CAL。
终端服务客户端访问授权模式
终端服务CAL只能用于每用户/每设备模式
在每用户/每设备模式，每个用户或设备需要一个单独的终端服务以访问任意服务器上的服务器软件。你可以重新将一个终端服务CAL从一个设备分配到另一个设备，永久或临时将终端服务CAL分配给某个用户或设备。 比如某个固定的员工请假的时候由临时员工代替。
终端服务器CAL和Windows会话在每服务器模式中均不可用。
虚拟桌面基础架构（VDI）授权—全新的Microsoft VDI Suites
Microsoft VDI环境完整且正确的授权要求对运行在中央环境的Windows客户端操作系统，以及在端到端DVI环境中的基础架构和管理组件，都必须具有授权。
对于Microsoft VDI环境中基础架构和管理组件的授权，客户有两个基本选项：他们可以使用RDS CAL为VDI基础架构提供授权，同时独立对VDI管理组件提供授权；或者可以从下列两种新的批量授权中选择一个使用：Microsoft Virtual Desktop Infrastructure Standard Suite以及Microsoft Virtual Desktop Infrastructure Premium Suite。这两个套件将最适合VDI场景的产品结合成了一个超值套装。
这两个新的VDI套件包括：
Microsoft Virtual Desktop Infrastructure Standard Suite（VDI Standard Suite）—包含使用和管理VDI所需的核心产品和CAL，其中有：
远程桌面服务（RDS）–TVDI套件的RDS组件只被授权在VDI环境中使用，并不包含使用基于会话的RDS资源的授权。
Microsoft Desktop Optimization Pack（MDOP）–系列技术的集合，可用于桌面虚拟化和管理，包括App-V。
System Center Virtual Machine Manager（SCVMM）客户端管理授权 –可为VDI宿主基于Microsoft? Hyper-V?的虚拟化组件提供集中管理功能。
System Center Configuration Manager（SCCM）标准服务器管理授权 –可为VDI套件中的（物理）VDI宿主提供集中的配置管理。注意：同时包含VDI和服务器虚拟化负载的虚拟化宿主无法通过VDI套件获得授权。
System Center Operations Manager（SCOM）标准服务器管理授权 –可为VDI套件中的物理VDI宿主提供集中的监控和性能管理。注意：同时包含VDI和服务器虚拟化负载的虚拟化宿主无法通过VDI套件获得授权。
Microsoft Virtual Desktop Infrastructure Premium Suite（VDI Premium Suite）—除了包含上述VDI Standard Suite的所有内容外，还包括：
App-V for RDS–可为RDS会话提供应用程序级别的虚拟化。
RDS–RDS授权并非被限制只能用于VDI场景，还可用于基于会话的桌面和应用程序场景。
VDI套件的授权只适合批量授权用户。为了简化客户的采购工作，可选择与VECD相同的授权架构，并使用基于设备的订阅模型。
重要：?这两个VDI套件的System Center管理组件被授权只能用于VDI场景中，不能用于VDI之外的环境。这意味着混合了服务器和桌面负载的虚拟化宿主的管理无法通过VDI套件获得授权。
终端服务器常见问题
Q. I have Windows Server 2003 Per User TS CALs. I’ve just upgraded one of my Terminal Servers to Windows Server 2008 R2, can I continue to connect that with my Windows Server 2003 CALs?
A.
No, you’ll need to buy Windows Server 2008 RDS Per User CALs for each user who accesses the new server. However, if you have Software Assurance on the Windows Server 2003 TS CALs, you’re covered and the upgrade is free.
Q. Can I use my Windows Server 2008 TS CALs to access RDS on a server running Windows Server 2008 R2?
A.
Yes, Windows Server 2008 TS CALs are functionally equivalent to RDS CALs, and can be used for connecting to Windows Server 2008 R2 RD Session Hosts and RD Virtualization Hosts.
Q. I have a mixture of users—some have only a single computer, others share a computer, and a few have multiple computers, but I really only need a single RD Session Host server. Can I use a mixture of RDS Per Device CALs and RDS Per User CALs on a single server?
A.
No, you need to either split the loads off to separate servers, or you’ll need to calculate the best value between RDS Per User and RDS Per Device CALs, since each RD Session Host server can only run in Per Device or Per User mode.
Q. My license server failed, and now none of my users can connect to the RD Session Host server. What do I have to do to get back up and running?
A.
Install a new Windows Server 2008 R2 license server, and migrate the licenses from the failed server. If you have the details of your original server and license packs, the migration doesn’t require a telephone call to the Microsoft Clearinghouse.
Q. I still have Windows 2000 Servers running Terminal Services, but we’d like to retire them and upgrade to Windows Server 2008 R2 to take advantage of RemoteApp. My client computers are primarily Windows XP-based and don’t need a license for Windows 2000 Terminal Server. What do I need to buy when I do the upgrade?
A.
You will need to buy a RDS CAL for each client computer, or for each user, whichever is more economical. Your Windows XP licenses are not supported by Windows Server 2003, Windows Server 2008, or Windows Server 2008 R2 RD Session Host servers.
Q. I have 100 users who use our line-of-business application running on the RD Session Host. However, there are never more than 15 users at any one time connecting to it. How many RD Per User CALs do I need to buy?
A.
You need 100 RDS Per User CALs. Each user must have their own CAL; there is no concurrent CAL usage. However, if some of the users share computers, it may be more economical to use RDS Per Device CALs.
Q. Do I need an RDS CAL if I am using a third-party technology such as Citrix XenApp, Ericom PowerTerm WebConnect, Quest Virtual Access Suite, GraphOn Go-Global to directly or indirectly access the server software to interact with the graphical user interface?
A.
Yes. An RDS CAL is required irrespective of the technology used to directly or indirectly interact with the graphical user interface. This includes (but is not limited to) the use of Windows Server 2008 R2 Remote Desktop Services or other third-party software that enables multiuser scenarios on Windows Server.
Q. Do I need an RDS CAL if I am not running a multiuser environment, but use functionality in Remote Desktop Services, for example RD Gateway?
A.
Yes, an RDS CAL is required for the use of any functionality included in the Remote Desktop Services role in Windows Server. For example, if you are using an RD Gateway server and/or RD Web Access to provide access to a Windows-based client computer, both an RDS CAL and a Windows Server CAL are required.
Q. If I currently am licensed under the Microsoft VECD program for my desktop computers, why would I need to purchase the new VDI Suite?
A.
Complete and correct licensing of a Microsoft VDI environment requires licensing of both the Windows client operating system running in a centralized location (VECD), and of the infrastructure and management components that enable an end-to-end VDI environment. The VDI Suites offer a complete value package for an optimum VDI experience.
Q. Why are the Microsoft System Center products required in the new VDI Suites?
A.
The Microsoft System Center products included in the VDI Suites are necessary to provide the monitoring, performance management, and configuration management of the virtualization components and physical VDI hosts enabled in a VDI environment.
本文转自xury 51CTO博客，原文链接：http://blog.51cto.com/xury007/321804，如需转载请自行联系原作者
