In bigger Terminal Server environment Citrix is almost equivalent to the words Terminal Server and Server Based Computing. Logically because Citrix is the founder of Server Based Computing techniques based on OS2 and later on the Windows platform.
Nowadays Citrix is not the only supplier offering Server Based Computing products anymore. Actually more and more manufactures are entering this market, so the choice of a SBC product is getting more and more complicated.
Claudio already wrote a nice article called To Citrix or Not to Citrix.
In this article we will be going one step further by discussing which components should be considered if you are would like to build a SBC infrastructure for your environment.
Why not use Windows only?
Why not use Windows only?
One of the most asked a question is: Why do I need Citrix if Microsoft Windows already has RDP possibilities? (Remember that many customers/managers do not know about other SBC products, so they do not mention another product here)
From a manager objective this question is not that strange, if you are using Citrix or another product you also need to buy license for Microsoft Terminal Services. Of course the manager will know that those products offer additional features but his big question is: are these features worth the price?
For small(er) environments Windows is a really good alternative if you want to implement all applications on Terminal Servers, because you only give the user a full desktop (or just one application automatically started in the full desktop).
Also all configuration settings must be done on all servers locally, because Microsoft does not provide a centralized tool for that (except the settings currently available in the Group Policy Objects).
In bigger environments missing options like Published Applications and Central configuration combined with the basic load balancing options of Windows 2003 the search can be started to add-on product to facilitate your infrastructural needs.
Windows Longhorn will also support Published Applications in Windows Longhorn, but no improvements are announced for load balancing and central configurations.
I'm not going to talk about Published Applications, central configuration and Seamless Windows in depth. Almost every SBC manufacturer is supporting those features in their products. Of course the implementation of one product is better than the other. Especially with the implementation of seamless windows is really different and the visualizing of the console is very subjective. The best thing is just to play around the product and decide what fills your needs the most.
This is mainly reason number one to think about additional software on top of Windows Terminal Services. In Windows 2003 Microsoft added Session Directory for reconnection to disconnected sessions, but still the Network Load Balancing protocol is not satisfying the needs to load balance your users over the server Terminal Servers.
Almost logically (but not every manufacturer is offering that) is a load balancing component that can be configured to your needs. I personal really like the load evaluator configured by user load. Load evaluators based on other resource like CPU, Context switches and pagefile swaps are unpredictable because the counters of these resources often fluctuate within a short time frame.
For this component my opinion Citrix is still very strong, together with Provision Framework and Ericom Powerterm WebConnect.
Monitoring is still one of the most required components by daily system maintenance, but I do not see many companies really using this component actively. Also if you have already a monitory system in your company the need to have this component in your SBC product is smaller.
Looking to the monitor component in the SBC products Citrix is definitely offering the best package. Provision Framework is busy with developing this component; the others are just offering very basic monitoring options.
As described in the article about Basic Concepts of the Terminal Server infrastructure to accomplish 100% identical servers, applications should always be installed chronologically. To guarantee this a tool to arrange this is necessary. If you do not have an additional software available (like Altiris or Wisdom) fort this task, it would be nice if the SBC product have this functionally integrated.
Till now Citrix is the only one that has this component available in their product. It is a pity that the component is still the same as in the Metaframe XP version.
Universal Printer Driver
Still of the biggest challenges in Terminal Server are printer drivers, so the Universal Printer Driver concept is developed. Even Microsoft (since Windows 2003 SP1) is offering some kind of Universal Printer Driver for Terminal Services. If you have just a few printer types in your organization available you probably do not need a universal driver component. If you need to support lots of printers, especially unmanaged printers and Universal Printer Driver could be very useful.
Remember that the Universal Printer Driver solutions in most SBC products are only available for auto created client printers like the Microsoft and Citrix implementation.
The Provision Framework product has also a universal driver available which can be used for network printers. Some SBC products do not offer a universal print driver at all.
Because many applications are running on one system used by many users it can happen that CPU and Memory resources are getting exhausted. Resolving this issue was for a long time reserved by purchasing addition products. Now also the SBC products are adding this component to their product.
For example within Presentation Server 4 Citrix added CPU and Memory management (licensed from RTO). Also Provision Framework has these features available in their product.
Secure Portal functionality
Access to applications and data from any place at anytime is almost a business requirement at this time. So the SBC product should support access to the applications from unmanaged locations preferable via the Internet. Of course the connection should be fully secured.
Almost every SBC product is offering this component in their product, which are all working fine. If you have a double hop DMZ check if this is supported by the product.
Microsoft will also implement this component in Windows Longhorn.
PDA's are also getting used more and more within the company. In one case they are used as a device to connect to the Published Application or Desktop. On the other hand they are also used a agenda and mail item, which need to be synchronized with the central store from Exchange, Lotus Domino or another product.
Using your PDA as connect device to applications or the desktop there should be a supporting client for the SBC product. Citrix is still the manufacturer that is has the most available clients. Other suppliers often have a Java client available that can be used on most devices.
Synchronizing your PDA is another story, because the device needs to have a direct connection with the program used for managing the agenda and mail. With the introduction of USB devices this became even more complicated when using Terminal Servers. Citrix now supports Activesync on Presentation Server 4, while Provision Framework has built-in support for Blackberry and Palm devices.
Profiles are also one of the challenges in Terminal Server environment (for more info see the article Terminal Server and the Profile Challenge). There is significant move from roaming profiles to so called Hybrid or Flex profiles.
Till now Provision Framework in the only product that is offering basic hybrid or flex profile support built-in the product.
User Environment Management
This component is still not recognized by many SBC products, but my view this is one the most important parts within a SBC implementation. If the SBC product has built-in features to manage the user environment is a big advantage. Think of Start Menu, Desktop and Quick Launch (with only assigned applications), network drives, printers, and lockdown of the environment.
Provision Framework is the product which is clearly offering the most features for managing the user environment.
There are lots of other components in the products available which could be useful for your environment. Think of TWAIN support for scanners (Citrix), Application Virtualization (Citrix), Workspace control (Citrix), preventing start-up of unauthorized applications (Provision), support to Legacy systems (Ericom, Propalms[old Tarantella]), Proxy for MSTS client (Thinworx, Provision) and maybe some other features.
Add-on Management products
When deciding which components are need for your infrastructure also think about other third party management products like Powerfuse, Appsense, Tricerat and so on. These are also offering most of the above mentioned component in their software products. Depending of your needs it can be useful to consider a basic SBC product with fewer features advancing it with an add-on management product.
For our technical guys this is not important, we would like to have the best product which makes our lives as easy as possible. But from a business viewpoint price is always an important component when selecting a product. Take this in consideration when defining the components you would you really need to have in your SBC solution.
At this moment the choice of an SBC product is not just buying Citrix anymore. There are lots of alternatives available. All the products have their advantage and disadvantages. When you are selecting a SBC product define which components as described in the article should be included in your products to fulfill your and the business needs.
Test the products on the defined components and decide in this way which SBC product is most useful for your infrastructure.
Article previous published at MSTerminalServices.org.