This Bulletin is the fifth in a series covering developments in computer technology and their value to business. Earlier issues examined computers and their components (i.e., chips, RAM, disks, monitors, etc.), printers and recent changes in data storage systems. This issue begins a discussion on computer networking. Future installments will continue with networking and go on to cover Internet connectivity, communications and computer/telephone integration.
Although computer networks have been around for nearly 20 years, they didn't come into mainstream business usage until the late 80s (the Bulletin's first coverage was in early 1987). Since then, they've been the most dynamically changing part of the entire computer business. This issue of the Bulletin concentrates on the uses of networks (which continue to expand), the types of networks in use, and the infrastructure that makes networking possible.
The reasons for using one may seem obvious, but most organizations with networks don't use anywhere near their full capabilities. These capabilities fall into three broad categories: collaboration, communication and access to shared resources.
Collaboration is the most common reason for first putting in a network. For businesses that have had central computers for a long time, the key factor is often allowing its PC users to access the main computer system. But this barely scratches the surface of the potential for collaboration using computer networks. The hottest area for collaboration in the next few years will undoubtedly be what's called "groupware".
Groupware capabilities include electronic mail (E-mail), personal and company-wide name/phone lists, document routing and shared "bulletin boards". But its most acclaimed feature is the ability (particularly of Lotus/IBM's Notes product) to hold electronic "meetings" that allow participants to view documents on their computers and revise them concurrently. Adherents claim this can be far more effective than actual meetings for some kinds of work (much like E-mail can be more effective than phone calls for some kinds of communication). There are skeptics, however, including some with years of Notes experience, who deride this whole notion.
The second reason for using networks is communications. In particular, E-mail has grown dramatically, largely because it's become standardized in the last two years. What this means is that anyone, no matter what E-mail service he uses, can now correspond by E-mail with anyone else on any other E-mail service. For those who don't use E-mail, it's like using FAX but better for three reasons:
The communications benefits of networks include much more than just E-mail, however. The depth and breadth of online information accessible via computer networks is hard to overstate. For years, most business-oriented information was confined to fee-based or subscription- only dial-in databases (e.g., Dialog, Lexis/Nexis, Dow-Jones, etc.), but the recent growth of the Internet has brought all kinds of new data online. Recreational use has created most of the growth to date, but that's changing rapidly. I expect that commercially-oriented databases (including many solely for business use) will soon predominate.
The most common reason cited for networking is to share high-cost or scarce resources such as printers and disk drives. This is actually much less important today than it used to be, since printer and disk prices have come down so much. Three of the most cost-saving areas today are access to data communications (covered above), special-purpose printers and reference information. A bank of CD-ROM drives (or a jukebox), for example, can allow the whole network to use an extensive reference library on CD right from the users' desks.
Centralized network management is kind of an "invisible" benefit to networking, particularly for back-up purposes. Individual computer users are notoriously lax about backing up their own machines, the importance of which doesn't become obvious until critical data is lost. Centralized back-up is faster, cheaper and easier than individual back-up. A smooth recovery from just one disaster can justify the cost of the network all by itself. Other network management activities such as "fine tuning" the network to increase its speed, distributing software updates, and isolating network problems can also be extremely valuable . . . the larger the network, the greater the benefit.
There are only three types of networks that most businesses need to be concerned with: local area networks (LANs), wide area networks (WANs) and internetworks. All three have been around for several years, but until recently only LANs and WANs had significant business use.
LANs, as suggested by the name, link computers that are local to one another, usually in a single building or a single interconnected "campus". Nearly all LANs in use today have a theoretical maximum transmission capacity great enough to support 50 to 100 attached computers. This maximum is dependent on the application, though, and can get down as low as 10 or fewer for heavy duty engineering or multi-media use. If more computers than this need to be linked, the network can be subdivided into interconnected sub-nets (called segments or rings) and still work as a single LAN. The need for capacity is growing as more users come onto their companies' networks and install more powerful software, but new LAN protocols will soon be available that have data transmission capacities ten to twenty times as great as the most common ones used today.
LANs are, by definition, local. When you connect several remotely-located LANs into a single network, that's called a "wide area network" or WAN. WAN connections are usually made over digital phone lines, the price of which has come way down in the past few years. But the capacity of these circuits is only about 0.5% to 15% of the speed of the LANs they connect, and the fastest ones (called "T1") are still quite costly. To keep from overburdening these relatively slow links, it's important to keep most users' data on their own LAN and avoid passing large blocks of data (such as graphics or long data files) across the wide area links.
Internetworking has been in existence for years, but has only recently become practical for business usage. By definition, an internet is a network that connects other networks. Although some other internets do exist, the one known as "The Internet", which extends around the world, is the most heavily used by far. There are two major differences between a WAN and the Internet:
The first building block of every LAN is cable [note: wireless technology is improving; but except for LANs that are impossible to wire, it's still too expensive and too slow]. In the past few years, the market has gone almost exclusively to two types of cable: unshielded twisted pair and fiber optic cable. Fiber optic has greater capacity and can be run for greater distances than twisted pair, but it's so much more expensive to use that its use is generally restricted to cable runs where the extra capacity or distance is required, such as floor- to-floor "backbone" cabling and connecting buildings through conduit.
Some cable system architects suggest running fiber to individual user computers, but this is generally "overkill" for two reasons:
The second LAN building block is the cable electronics: hubs, switches and routers. These devices provide a connecting point for the cable and control how the data flows through the network. The newest devices can re-route the data when sections of the network get over-crowded and slow down. The least expensive units ("stackable hubs") are fine for most small LANs. However, the newer and more expensive "switching" hubs and routers (sometimes combined with stackable hubs) are better in the large LAN environment. When WANs and Internet connections are involved, high-end routers are the best choice.
The next Business Automation Bulletin will focus on network structures and cover, in more detail, just how switching and routing fit in.
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Copyright © 1995 Business Automation Associates, Inc.