What is it: a Network Computer
Applications: best suited for fleet applications in which staff are carrying out a well-defined set of data-entry or data-retrieval functions; also works with ordinary PC applications
IBM is fully committed to the apparently radical concept of the Network Computer (NC). An NC is a kind of stripped-down PC that combines easy maintenance and support of the dumb terminal with the graphic capabilities and appealing front-end of the PC.
Although IBM doesn't believe NCs will replace PCs, it does think they will take a significant share of the market. Indeed, the company is confident NCs will replace dumb terminals and become a low-cost alternative to PCs.
The Network Station is the first of a series of NCs from IBM. Priced at around u450, without a monitor, it is due to ship in volume by the end of the year. The exact details of the product are still being finalised, but Business Computer World visited IBM's Research Labs at Hursley near Winchester to see how the situation is coming along.
NCs are different to conventional PCs because they are optimised for distributed computing. They work only when attached to a local area network or the Internet. This means an NC must be evaluated in a different way to an ordinary PC. The NC itself isn't as important as what is happening on the servers it is attached to.
This review concentrates on IBM's software plans at both the server and NC end, because this defines the sort of applications these new devices will be suitable for. But first, it is useful to discuss the Network Station itself, as this will clarify IBM's NC concept.
The hardware consists of a small black box about the size of a small notebook PC. It has almost no permanent data storage - no hard disk, no floppy disk drive, and only a limited amount of ROM. Data and program code are downloaded across the network, as required, into RAM memory, which loses its contents when the NC is turned off; 8Mb is fitted, which can be expanded to 32Mb. Local processing capability is provided by a non-Intel processor, a 66MHz PowerPC chip.
It is clear that the network link is essential. Both standard 10Mbits/sec Ethernet and Token Ring network adaptors are built in. IBM claims it will also provide the option of 5250-style co-ax connection, so the NC can connect to existing terminal cabling.
The heart of the matter
The built-in display circuitry is based on a standard PC chip from S3.
It supports a high refresh rate - a flicker-free 85Hz at 1,024x768 on the IBM 15in monitor used in tests. Because the NC contains no fan or other moving parts, there is an even power supply to the display circuitry.
The Network Station has little hardware, so doesn't use much power or generate much heat. Both it and IBM's monitors powerdown to a standby mode during periods of inactivity, further reducing power consumption.
Where there is limited space, Network Stations can be fitted in racks or built into desks and left permanently switched on.
The only part of the machine you may need physical access to is the PC-Card slot (formerly PCMCIA) at the front of the machine. This takes Type-II PC-Cards, and can be used for various purposes. For example, it can be used for custom application code held in flash memory, or for a SCSI interface which then allows the connection of peripherals such as CD-ROM drives or bar code scanners.
Some versions of the Network Station come with a smart-card reader instead of, or in addition to, the PC-Card slot. Smart-cards can have a small processor built onto them, which makes them ideal for security applications.
The smart-card can be used with a password or personal identification number (PIN) to provide a competent two-stage identity check before allowing access to the system.
The on-board processor can be used as part of a data encryption and decryption process, making the data unintelligible to anyone without the right card.
When a machine is switched on, several things can happen. For applications requiring the maximum security, you might need to insert a smart-card.
Or, where easy access is more important than security, you could just turn on, with the server identifying you by the NC's own ID.
The Network Computer edge
Once you've identified yourself, one of the advantages of the NC over the PC becomes immediately apparent: because you are not getting data out of a built-in hard disk, it doesn't matter which NC you use. The server allows you to access your own set of files and applications, and set up the NC with your stored personal preferences. This makes NCs ideal for hotdesking (see Technology in Action, page 82).
IBM's Network Station conforms to the NC Reference Profile devised by Oracle, the originator and main advocate of the modern NC concept. But this doesn't mean the Network Station uses the same operating system as other NCs.
In fact, the NC operating system has relatively little to do, because most of the applications are executed at the server end. The operating system's main purpose is to handle basic input-output functions. IBM is using what is essentially a UNIX kernel.
IBM has chosen a different route to Acorn. Whereas Acorn includes the whole operating system and other software in ROM, IBM maintains it makes sense to download as much of the operating system and other software as possible. This fully exploits the advantages of the NC when it comes to easy updating and version control.
When IBM's Network Station ships it will also have a so-called 'native' browser. It will be written in the PowerPC's own instruction set, so it should run efficiently. This is being developed for IBM by Netscape's Navio offshoot.
However, this proved no problem, as we ran Netscape Navigator 3 browser instead - the one familiar to the many Windows users. What's more, it runs effectively.
A protocol called Intelligent Console Architecture (ICA) allows ordinary Windows applications to run on the Network Station. It was developed by a small Florida-based start-up company, Citrix, in which Microsoft now has a six per cent equity stake.
ICA, like X Windows, allows an application running on a server to display across the network on client machines. It can also receive information from client keyboards and mice.
The difference with X Windows is that ICA is more efficient, usually requiring less network bandwidth. This is because the NC at the client end does much more of the work of drawing a screen than an X Windows terminal does.
The NC takes compact descriptions of the screen from the incoming ICA datastream and draws them. It adjusts the image to the resolution of the particular display and handles functions such as window scrolling and cursor movement locally.
As well as having ICA-handling software at the client end, Citrix software is also needed at the server end. The server product is called Winframe, and because of an agreement with Microsoft, Citrix is allowed access to the inner workings of Windows NT to develop it.
Winframe turns Windows NT into a multi-user operating system which can run multiple Windows applications sessions on the server for clients across the network. Winframe generates the outgoing ICA streams at the server end, and handles incoming ICA-encoded keyboard and mouse information from all the remote sessions.
All the application code executes at the server end, where the data also typically resides. So, while you have cheap, thin diskless clients running Windows applications, you need a big fat server. Just how fat is a key question if you are looking for the NC to save you money.
The main requirement is plenty of memory. Citrix claims you need 16Mb of memory just to run the software, plus between 4Mb and 8Mb for each user.
The amount depends on the number and complexity of the applications the users are running. However, the lower limit would probably apply to straightforward jobs such as word processing or order entry.
These figures give a memory requirement at the server end for a 15-user system of between 75Mb and 135Mb. Although it seems a lot, memory is only needed for users who are actually connected to the server and using the application software. Compare this dynamic allocation of resources to a conventional PC, which has a fixed amount of memory permanently fitted - these days, it is typically 16Mb.
Citrix ICA system works well, even with a small server (an IBM Thinkpad).
Performance depends on the server, network link and NC being used. It would be unfair to draw any conclusions from the prototype setup reviewed.
The bandwidth requirement increases with highly graphic applications, where there is really no alternative but to move masses of data across the network. But ICA looks a feasible approach for running everyday Windows applications. This highlights one of the great surprises about IBM's NC.
Hand in hand
Far from being a Microsoft killer, as Oracle originally intended, many of the first crop of NC vendors have decided, like IBM and Wyse, that working with Microsoft is the way to give the NC access to a ready-made software base.
Indeed, IBM is, to some extent, allied with Microsoft, having announced its intention to offer Windows NT on its key hardware platforms - the AS/400 minicomputer line, the RS/6000 scalable RISC workstation and the S/390 mainframes. This means that eventually all of these established platforms will be able to host networks of NCs running ICA sessions.
Having said all that, the Citrix-Windows NT approach isn't the only software route available to the Network Station. One of the simplest, once the Navio Web browser is available for the IBM machine, is to browse HTML or Java pages across the Internet or company intranet.
The Notes connection
This approach fits in well with IBM's own software plans for Lotus Notes.
IBM now owns Lotus and, over the last year, has been adapting Notes to run not just on Windows but also directly on the AS/400 and RS/6000 lines.
It has also been extending Notes into a Web publishing tool.
Where does Java fit in to all this? IBM is certainly very active in Java development, with its Hursley location at the forefront. The company is developing everything from basic tools, building Java support into its operating systems, to writing toolkits for independent software vendors developing their own applications. For example, IBM is developing Java encryption tools to use in secure transactions.
So what applications is the IBM Network Station good for? Although it can run any Windows application, this is just the icing on the cake.
Where the NC concept really scores is in ensuring the uniformity of software across a whole number of PCs.
This makes it ideal for fleet applications where you want everyone working in a predictable, consistent way - tasks such as order entry, credit control or selling financial products over the phone.
Verdict: the Network Station is essentially a machine for the new type of office worker - large groups of people doing fairly repetitive tasks under strict management control.
By contrast, for 'empowered' knowledge workers, trusted to seek out not just their own data but often the tools they use to make sense of it, conventional PCs are better.
The PC is more flexible, and allows users to add to its capabilities themselves.
But the truth is, the PC is still very labour-intensive, both for users and the systems support people. So if NCs live up to their promise of providing a more predictable kind of computing, many organisations can be expected to move more easily-defined tasks to them.
Java talks NC language
Java fits in well with the NC concept as it can help distribute the processing load more efficiently between server and client. In many sales and accounting applications people spend a lot of time on tasks such as filling in forms.
Java can perform input validation at the client end without burdening the network. For example, Java can do the modulo-13 checks used in data verification in many banking applications.
Java is also useful for transforming the display of data. This is particularly interesting when applied to old applications, especially ones where you don't want to interfere with the core logic.
Leaving the core logic alone, you can write an attractive front-end in Java. For example, new Java code running at the client end could transform an old airline booking system, adding not just better graphics, but plain English descriptions in place of unfriendly codes.
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