Escaping the relational database paradigm:
Case management in the High Court of Australia

Delivering Notes to the desktop

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The Court faced two significant problems in delivering the new system to the desktops of users.

Emerging thin-client technologies such as Citrix WinFrame offer a solution to both of these problems. Thin-client technologies allow remotely based staff to access bandwidth-hungry applications over both standard telephone lines and ISDN connections at performance levels that would normally only be achieved over a 10 Mb per second network connection. Additionally, these technologies allow applications that require a 32-bit operating system to be accessed from desktops using older 16-bit operating systems.

The bandwidth problem stems from the fact that client server applications perform much of their processing of data on the client workstation rather than on the server. This normally requires the installation of a large and complex client. Often the sheer quantity of data passing between the client and server across either an ISDN or dial-up modem connection results in sluggish performance.

Citrix WinFrame allows a user located in another State to take control of a virtual computer inside a separate dedicated server located in another location, which will then complete all data processing locally. Importantly WinFrame allows all data processing to be completed locally. The latest version of the software operates by slicing the application's logic, sending only interface information across the connection. Once operational, any 16- or 32-bit application can be accessed remotely at performance levels comparable to those obtained within a 10baseT LAN using structured cabling.

Whilst a number of different remote control software products were available (such as NTrigue), Citrix WinFrame5 running on a modest Windows NT server6 was eventually selected as the preferred solution for the High Court.

The WinFrame licensing arrangements chosen by the Court allow up to 15 concurrent sessions on the Citrix server. There is no significant degradation in response times with this many concurrent users (see Figure 13). Additional user licences can be added at a later stage if necessary; a large Canberra-based organization7 recently commissioned a 300 concurrent user Citrix WinFrame server.

Figure 13
Figure 13:  Performance degradation using WinFrame with 1-30 concurrent users.4

The High Court's WinFrame LAN/remote access configuration is shown in Figure 14. A user can access the server from an ISDN, dial-in modem or Internet connection using an Intel-based PC (286 or above), Macintosh or Unix workstation. Once connected by modem, 32-bit applications can be run at nearly the same speed as would be achieved if the user were actually connected to the LAN.

Figure 14
Figure 14:  The High Court's WinFrame LAN/remote access configuration.

One of the benefits of the WinFrame solution is greatly simplified administration of applications. In a traditional client/server architecture, the arrival of a new application or application upgrade would generally demand the immediate reinstallation of a new client on all users' PCs. This is a time-consuming exercise, particularly if the client is physically located in another State. As the Citrix WinFrame solution requires the various application clients to be installed on a single processor, applications, software updates and patches can be rapidly and easily deployed.

Utilizing WinFrame, users can still cut and paste text between local and remote applications, and local printing is still possible. WinFrame allows each user to have a unique profile recorded on the server. User access, screens and printing options can be fully customized. In effect, a "virtual" PC desktop is configured for each user.

One notable advantage of a WinFrame solution is a significant extension of the life of existing hardware. For example, an organization with a large collection of old 286/386 PCs, and heritage cabling infrastructure, could install a single Citrix WinFrame Pentium server and simulate the processing speed of the Pentium computer across all WinFrame client workstations. Users could access the latest 32-bit resource-hungry applications from their existing 286 PCs, without memory or processor upgrades.

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