Latest Thin Client Solution

This is the latest version of Meta-frame from Citrix, a thin client solution that runs on Windows NT 4.0/2000 with Terminal Services installed. It can be used by large organizations, universities and training institutes, who need to deploy critical applications across their networks while including users on multiple platforms and even put to use older machines, which they might have. An important addition to this release is something called Nfuse, which lets you run applications through a Web browser.

As most of the processing is done at the server end, it must have a pretty mean configuration to take the load. Core Metaframe services need 64 MB RAM, and additional RAM depending on usage. About 8 MB RAM is needed for each heavy user. It’s best to go for a multi-processor server where you can add more processors as and when needed. You’ll have to ensure that the server never goes down, or else the entire network will come down. Metraframe lets you create server farms, where multiple servers take the load. so, even if one fails, the remaining will keep the network running. Metaframe XP servers cannot join existing Metaframe 1.8 servers, although they can operate in a mixed mode for license pooling and load balancing.

Metaframe allows clients working on different platforms to connect to a central server and run the latest Windows OS and its applications. It has clients for Windows3.x/9x/ME/2000/CE, DOS, UNIX, Linux, OS/2 Warp, Mac or Java Virtual Machine (any application, browser etc.). Client diskettes for Windows 3.x/9x/NT and DOS can easily be made through the ICA client creator wizard. Others can be installed directly from a separate client software CD that comes in the package. Clients can choose the protocol to connect (TCP/IP, IPX, SPX, and NetBIOS), encryption level (40 bit to 128 bit), and even choose the server they want to connect to. They can also choose the color depth and screen resolution (up to 1600x1200) at which to connect.

Independent Communication Architecture

The Citrix clients and server communicate using ICA (Independent Computing Architecture), where only keystrokes and mouse clicks are exchanged, while computing takes place at the server end. ICA has been improved with a new feature called SpeedScreen, which reduces transmission of frequently repainted screens to reduce bandwidth consumption. Connectivity methods range from normal telephone lines or LAN to broadband connections and the Internet. During installation, you can also setup any TAPI compliant modems on your server to give remote users dial-in access. Another new feature we found in this version is called ICA Session shadowing, which allows ICA clients to monitor and interact with other ICA sessions. This allows them to observe user activity or troubleshoot problems of other users. This feature can be useful for training purposes, allowing both teacher and student to interact.

Application Publishing

One of the most important features of Metaframe is Application publishing, which can be used to allow clients to run any application from the server. It’s pretty simple to configure, and you can define settings like color depth, resolution, sound support, encryption level and users allowed access to an application. You can specify which servers host this application, in case of a server farm. You can also create desktop icons and put shortcuts in users’ start menu for any application. This works only for Win32 based clients. Others have to do it manually. Such applications will even integrate users’ local windows environment. Users can use Alt+Tab keys to switch between local and remote apps, and even use the clipboard for local and remote apps.

NFuse

NFuse used to be a separate product, which now ships with MetaframeXP. It’s an application-publishing tool that lets clients access applications through a standard Web browser. It consists of an NFuse Web server for hosting the NFuse Jave Objects, and webserver side scripts. These are used for authenticating users and retrieving application information. NFuse can run on various Web servers including IIS 4 and 5, Netscape Enterprise Server 3.6, iPlanet Web server, and Apache Web Server on Linux. For each of these, NFuse has different Web server extensions. We installed them for IIS 5.0 on Windows 2000 Server. It asks for location and port of the Metaframe machine that will host the applications. An important feature here is that it lets you use the default HTTP port to run its own service also, which means you don’t have to open additional ports. It also copies all ICA client files from the CD, which are later used to install the client on users accessing the site. NFuse also includes a Web Site Wizard to design and customize your site.

When a user visits the NFuse site for the first time, his machine is checked for the necessary ICA client to run the published applications. If not found, the user is prompted to install the client, after which the user is authenticated, and the published applications are available for use.

Sachin Makhija