CITRIX-Newbie: what is CITRIX? 3

[Krolsky]

Hello everyone,

I am a newbie to Citrix that knows a very little bit about it. Basically I know that it works with server-side applications that you can work with through a terminal. Updates happen on the server and as a network administrator you don't have loads of PCs to update and such.

However now back to my question:

I would like to know where I can find some easy to read info on Citrix. How it works and a basic hardware setup and such. Maybe there are some sites/forums where I should better post this question?

Well that's about it with my question here. Remember I'm a bit of a newbie on this

Thanks!

Krolsky

 

[JohnTcolo]

There are tons of information to be found at the site below. It is the official Citrix Support site.

Good Luck.

http://support.citrix.com/

 

[Krolsky]

Cool thanks!

So far what I understand is that "Citrix" is more a company name that has become a name that people use to say they have software from that company. (I hope this is right.)

Now I am back to the start too since I found out that there's quite a lot of different software from Citrix (the company). What I understand so far is that Metaframe xx is the main serverprogram (OS maybe?) and that there is several clients that can connect to the server. Besides that there is this program Nfuse that makes it possible to connect through the internet.

Please tell me if I am at least a little bit right about this

Thanks again.

 

[JohnTcolo]

In a nutshell: Citrix Metaframe is a product similar to Terminal Services from Microsoft. It sits on top of it and is dedicated to rapid communications in LAN/WAN environments.

 

[DaveRS575]

You are correct...Here is a simple thumbnail sketch...

Citrix "Metaframe" is the framework that runs on top of the "Microsoft Windows Terminal Server" environment. It enables you to "publish" applications that are installed on the server to users out in the user commmunity who do not have this software installed on their PC's. It gives them full application functionality without the need to install it on their machines.

Nfuse is a web front end, that gives the users a place to go and launch these applications. They go to a web site, log in, and voila! A list of all applcations that have been published in Citrix Metaframe that they have been permissioned to run.

A couple of cool things about Citrix Metaframe versus Terminal server by itself, is that it gives you the ability to publish an entire desktop, or down to just one single application. It uses a special protocol called "ICA" which basicially speeds things up tremendously by transmitting ONLY the information that has graphically changed in the session, rather than rebroadcasting the entire screen image every millisecond. Much faster than just a TS session.

The most functional usage seems to be client server applications. For example, lets say I have a massive Oracle Database in London, and I am here in NY. IBefore metaframe, I woul dhave to connect directly to the Oracle DB over the WAN dragging tons of data over the WAN clogging it up and making everyones life miserable. With Metaframe, I connect via a session to the Metaframe server in London, and I see everything I would see as if the app is urunnin on my workstation, but its really not. It's running on the London Citrix server so performance is fast, bandwith utilization, minimal and I could even be dialed in via a 14,4 Modem and see comparable performance as the people working in London would. Very nice.

That's a nutshell description.. there is alot more to it, but there ya go.

 

[Krolsky]

Wow thanks alot for that one!!

I now have read so many things about this that I think(!!!) that I have a pretty good idea on what Citrix is and how it works.

I have yet another question though:
How does the ICA protocol work? Is there a way to monitor server activity through monitoring the ICA protocol requests? Also is there a site where the ICA packages are explained (i.e. what do the packages consist of)?


I know now that traffic from server to client and back is controlled by the ICA protocol. However is there a possibility to monitor this traffic? See what kind of requests are made from which terminal and when? Also if those requests are granted I'd like to know if there's a way to time that.



Thanks again!

 

[CitrixEngineer]

Here's a little bit more info: Citrix actually developed the software that became Microsoft terminal services back in 1993 for OS2. This software was called pICAsso. This was prted to Windows under the name WinView. Microsoft liked the idea and allowed Citrix to modify the Windows 3.51 kernel. WinFrame was born in 1996.

Two years later, MetaFrame 1.0 was unleashed on the world. No longer integrated into a special version of Windows, but a product in its own right, Citrix licensed the core software back to Microsoft, who called this project hydra. You can still see the evidence in the terminal services database (hydra.mdb).

The license expired last year, and now Microsoft own terminal services as part of Windows 2003 Server - hence the new developments. However, Citrix have developed MetaFrame to far more than an add-on, as most of the world's top companies won't even consider using terminal services without MetaFrame - and for good reasons (too many to list here!).


How does ICA work? On a high level, it splits the logic from the display via a set of programmable Virtual Channels. On a lower level, Citrix's GINA hooks around Microsoft's, and a per-session copy of the kernel is loaded from one of two pre-prepared "idle" sessions - copies of win32.sys and winlogon.exe - via csrss.exe. There is an SDK and the Citrix Developer's Network if you'd like to explore this further.

To answer your second question, you can monitor ICA traffic using Resource Manager, a component of MetaFrame Xpe. It includes counters to monitor IMA and DataStore updates and broadcasts among other things.

Hope this helps - see you on CDN (via Citrix.com)

 

[Krolsky]

Thanks alot once again. Everyone has been of great help I hope to be of use myself somewhere in the future