Ensight – Jeremy Wright

Okay, he didn’t really. But we did get into a conversation about the benefits of Citrix, specifically over Terminal Services.

Since I never got around to writing why I believe CITRIX rocks for you guys, I figure I’ll just copy my email I sent Alex (great guy, great blog by the way).

Hey,

I’ll try to go through this without getting myself or you confused. Bear with me if things sound off, and feel free to ask questions.

I’ll start with the VPN tunnelling / SSL / etc. CITRIX has it’s own packet (ICA packet) it’s own encryption (ICA encryption, using a public / private key algo… It’s actually an S+P/private key, but yeah); etc. So it’s not really VPN, and it’s not really SSL either. You can choose to use either of these as well (since CITRIX connectivity happens through standard TCP/IP on port 1494) but by default all you have to do is open that port on the firewall. And even then… You dont’ ‘need’ to, there are other ways around it so that communiation happens strictly (for instance) over port 80.

As far as how CITRIX is better than Terminal Servies, some history might be useful. Back in the early days of IBM, a developer came up with a way to make computers multi-user available (ie: multiple users having full access to the entirety of a system, in a fully segmented way so they weren’t interfering with each other). As IBM often did at the time, it felt there was no future for this technology. So, CITRIX was formed.

CITRIX decided not to stick with IBM, but to develop for Windows. They reached a deal with Microsoft whereby they would have full access to the source code they needed, and in return MS could have a cut-down version of Terminal Services that they could distribute. What eventually evolved was a give and take relationship whereby changes made to either ‘version’ are sent to the other company, with the understanding that MS was not allowed to produce a more advanced version of Terminal Services than CITRIX offered.

So, that should cover some of the history and connectivity, but the key issue is “what is Citrix”, as well as “what makes it so damn good”.

I wish I knew your experience with other systems because then I could draw some comparisons, so excuse me if I oversimplify.

At it’s core, CITRIX is terminal services, on speed, with management, load balancing, web-delivery of applications (no, not like .NET); seamless integration, authentication (within CITRIX or tying into AD or eDirectory); etc.

Simple, right?

Before I forget, I actually have a server + 5 CAL license pack for Citrix. If you’re interested and have spare gear I could send it to you for a few weeks (it’s full license, not trial).

As for how CITRIX is better… It really depends on how you want to use it. You could use it, for instance, to make an application available to all of your users without the need for them to install any software. They would go to a website, click run and it would open it as if it was on their computer, though really it would be running off the server. It wouldn’t be in a Terminal Services window (one of the agreements with MS is that they couldn’t provide seamless solutions, hence the TS window). It would have a taskbar icon for Wordpad (if it was Wordpad); the description of the file, etc. It would behave as if it was on their system and the user wouldn’t know the wiser (access to their local drives, their printers, etc).

In this kind of scenario, you upgrade once (on the server) and everyone has access to the latest version of, for instance, Office. Speed and latency aren’t an issue, because all that’s required for full streaming is 22K/sec connectivity. Something easily achieved on just about any network.

Or, perhaps you want to deliver applications remotely. Again, you could use a web interface to easily do this so that, for instance, your travelling execs (yeah, I know, you work for a law firm); wouldn’t use Outlook Web Access, but the actual full Outlook client itself, and have access to all their personal folders (if you do non-Exchange folders) and everything.

Or, maybe, you have employees who work from home but need full office connectivity and all the applications. Sure, you could use VPN (but then you have to go through the hassle of application mirroring). Instead you could either deploy the application, or you could ‘publish a desktop’. This is basically delivering to them a full Windows environment with everything they need, fully integrated. They connect to your CITRIX farm, and boom they have the start menu items, desktop shortcuts and all the applications available to them. Instantly. VPN? Pshaw

For some organizations, they want to use Windows, but get away from MS licensing. So if you wanted to go all Linux, but not use Linux, you could actually have the PC boot into a fully CITRIX environment, and the only MS licensing you’d pay is site-wide Terminal Service licensing (about 25$/user). After that, no Office license fees, no Windows license fees, and little need for expensive A/V software either).

Yes, CITRIX can be damned expensive, I know. But it does present some interesting options. And that’s without me getting into all the cool authentication, centralization, management, load balancing and security features.

Not sure if that helps or not.