Windows Server 2003 Versions
Similar to Windows 2000, there are multiple versions of Windows Server 2003. These include Web Server, Standard Server, Enterprise Server, and Datacenter Server. Terminal Services will run in “Administration Mode” (installed by default and now called “remote desktop”) with any version of Windows Server 2003. However, if you want to use Terminal Services in “Application Mode” to allow many users to connect and run remote applications, you cannot use the Web Server version of Windows Server 2003. (There was talk of requiring at least Enterprise Server, but thankfully support for Standard Server was added when Beta 3 was released.)
New Enterprise Features
To continue to add value to Windows Server (and perhaps to compete against some of the third-party offerings such as Citrix MetaFrame or New Moon Canaveral iQ), Microsoft added a “Session Directory” to Terminal Services 2003. In multi-server environments, this allows a user that disconnects from one server to automatically be routed back to that server to reconnect to their existing connection. (This feature requires the Enterprise Server or Datacenter Server versions of Windows Server 2003.)
In order to use the session directory, you must configure one specific Terminal Server to maintain the session directory information. This server tracks which users have which sessions on which servers via a local JET database. Then, enabling the session directory service on the other servers and pointing them to the session directory server causes them to check the session directory to see if there are any disconnected sessions for each user that logs on. (See the configuration screenshot below.) If so, the user is dynamically routed to the appropriate server.
A New Version of the RDP Protocol
Microsoft has updated the version of the RDP protocol that ships in Windows Server 2003. The new version, 5.2, offers several enhancements over version 5.1. For starters, RDP 5.2 supports all types of mapping, including printer ports, COM ports, the Windows clipboard, drives, and audio. (USB mapping is still not supported, although USB printers and drives are.) RDP sessions may also be 24-bit color, and resolution is limited only by the resolution of the client device. (The 1024x768 limit no longer applies.) With version 5.2, RDP is now very competitive to Citrix’s ICA protocol.
New RDP Client Features
Windows Server 2003 ships with an updated version of the RDP client, commonly referred to as the “remote desktop connection client.” This client, which is even newer than the one that ships with Windows XP (although it’s included in XP SP1), makes use of the new features of RDP 5.2.
The new client offers many more connection and configuration options than older clients. For example, Microsoft added support for various user “experiences.” (See the screen shot below.) This option allows users to manually specify their connection type (i.e. Modem, LAN, Broadband, etc.). The client software will automatically select the most appropriate configuration options.
When used with Terminal Services 2003, the new RDP client also allows for automatic time zone matching on a session-by-session basis. This lets multiple users in different time zones run programs on the same server, with each user’s session clocks and time zone settings automatically matching their client devices.
The biggest changes in Terminal Services 2003 are in the licensing arena. (Big surprise!) Most important is the fact that Microsoft is introducing a “per user” licensing option in addition to the “per device” licensing model that we’re all used to. “Per user” licensing enables one user to use only one license, regardless of the number of devices from which he connects.
“Per user” licensing is not mandatory, although an administrator must configure each server to function in the new “per user” or the traditional “per device” licensing mode (see the screen shot below). One server cannot offer both types. However, one Terminal Services Licensing Server can maintain both types of licenses for multiple Terminal Servers.
With the creation of “per user” licensing, Microsoft no longer offers the Terminal Services Internet Connector CAL—good news to many people.
Another important licensing change is that with Terminal Services 2003, you are required to purchase a Terminal Services CAL for any client operating system, including Windows XP. However, any copy of Windows XP that was purchased prior to the release of Windows Server 2003 will be “grandfathered” in, and will not require an additional TS CAL purchase.
Also, in Terminal Services 2003, you can now install the TS Licensing Service on any member server in an Active Directory environment. You are no longer required to install it on a domain controller. (However, if you do this, be aware that Terminal Servers will not be able to automatically discover the license server. You will need to manually point them to the proper server.)
Furthermore, Microsoft now gives you the option to restrict which servers may receive licenses from particular TS licensing servers. This helps prevent one department’s TS CALs from “disappearing” to another department. In Terminal Services 2003, you can create a list of servers that are allowed to obtain TS CALs from a particular license server.
Like in Windows 2000, Windows 2003 Terminal Services license servers have two different license grace periods. The first is the number of days that a Terminal Server will accept connections without being able to connect to an activated license server. The second is the number of days that a temporary license is valid for. (Temporary licenses are granted to client devices by an activated license server when it has exhausted its inventory of TS CALs.) In Terminal Services 2003, both of these license thresholds have been increased to 120 days (up from 90 days each in Windows 2000.)
Finally, in response to customer feedback, Microsoft has completely rewritten the Terminal Services License Manager. The new version is much easier to use, and it supports many different types of license programs.
Microsoft has really done their homework and added some nice features to Terminal Services 2003 when it comes to administration. First, all Terminal Services properties are now exposed via ADSI. This means that you can, for example, write a VB Script that configures any user object property—including Terminal Services-specific properties such as remote control settings and TS profile paths.
Similar to the ADSI properties, Terminal Services 2003 also exposes all Terminal Services properties as Group Policy objects. In AD environments, you can now create Group Policies that control any user object property.
Lastly, the “Configure your Server” wizard now includes Terminal Services option. Selecting this option steps you through all the necessary configuration settings needed to bring your Terminal Server online.
Room for Improvement?
Terminal Services has come a long way since Microsoft first licensed the technology from Citrix back in 1998. However, third party tools are still needed to create true enterprise solutions.
For example, Terminal Services 2003 still doesn’t have “real” load balancing. Network load balancing (available in all versions of Windows Server 2003) will load-balance up to 32 servers. However, this load balancing is based on network utilization. This is not as useful as load balancing based on CPU usage of number of users. Also, if you want to scale larger than 32 servers, you’ll have to implement DNS round-robin addressing between load-balanced server groups.
You can also use Windows component load balancing to create clusters of Windows 2003 Terminal Servers. These clusters can share more intelligent information than network load balancing, and they have support for N+1 redundancy and dynamic failover and fail-back. However, Windows Server 2003 clusters are limited to 8 nodes.
Should you upgrade your Windows 2000 Terminal Servers to Windows Server 2003? The answer depends on your situation and whether you’re using third-party tools.
As you’ve seen, RDP 5.2 and Terminal Services 2003 provide many of the features that used to be only available via third-party tools. However, the third party tools still give you amenities such as application publishing, seamless windows, anonymous user support, and non-Microsoft client access. Terminal Server 2003’s features are evolutionary, not revolutionary.
about the author
Brian Madden is a freelance consultant based in Washington DC. He focuses on ubiquitous computing—helping customers provide access to critical applications for users regardless of client device, platform, location, or network connection. He is the author of two bestselling books about Citrix, most recently Citrix MetaFrame XP: Advanced Technical Design Guide, Including Feature Release 2. He is also the co-author of the upcoming book Terminal Services for Microsoft Windows Server 2003.
Brian Madden - Terminal Services 2003 Overview.pdf