How networks work now

Building Operating Management, Nov 1998 by Boon, Cory, Kepekci, Steve

PREMISES DATA NETWORKING HAS BEEN A PART of the office landscape for three decades. In the 1970s, it used a centralized system model, with all user communications directed to a single mainframe or minicomputer where all processing took place. In the 1980s, the desktop terminal was replaced by the personal computer (PC), and groups of PCs in a common location were interconnected to form local area networks (LANs). The objective was to have the best of both worlds: the flexibility and variety of PC software on a machine configured to the user's requirements, combined with access to other devices, including mainframes and minicomputers.

In these decades and through the early 1990s, premises data networking was focused exclusively on providing services and resources to users operating within the organization. Standardization was relatively easy. Now, organizations are using the Internet to extend network services to external parties. Standardization is much more difficult because, in most cases, one organization cannot force another to adopt its networking products and practices. Despite that difficulty, the browser should be seen as a complement to the telephone, the photocopier and the fax machine: each a radical innovation at the time it was introduced, each used to transfer information between individuals and groups, and each a standard business tool expected to be found in any office.

To understand network growth, it is useful to look at the hierarchy of components, both physical and electronic, in a network. At the highest level, there is the digital content created and manipulated by users. Below this is the applications software, used to create the content. Next come the desktop or laptop PCs and their operating systems. These three levels can be collectively referred to as the user infrastructure. They are dynamic, changing all the time as users create new files, upgrade their software or buy new PCs.

The next three levels can be referred to as the network infrastructure. They are less visible to users and much more stable, because changing any of them involves major expenditures in time and cost. First, there is the group labeled networking equipment. This is a collection of servers and network operating systems, communications devices (such as hubs, switches and routers) and telecommunications circuits. Below this level is the cabling system, which physically links the network devices. The pathways and spaces dedicated to the cabling system and the networking devices form the lowest level in the hierarchy.

Network expansion and growth occurs in three directions, often simultaneously. First, there is internal-led growth, caused by an increase in the number of organizational users and departments requiring network and Internet access. External-led growth is driven by pressure to provide network access to parties outside the organization, like customers, consultants and suppliers. All such connections can be made securely through the Internet, allowing non-staff access to organizational data. The third direction of current growth is content-led, where user-created files grow exponentially in size because of high-resolution image, sound and video content.

What Network Users Want

As the organizational network grows, it evolves from a useful tool to an essential resource, especially for companies with an extensive or total web presence. For all companies, there is pressure from both internal and external users to increase the number and depth of services on the network.

Historically, LANs were set up to share printers, common software applications and user-created files. Electronic mail was the first true network application, enabling messaging on the LAN. While these services continue to be in demand, others have also joined the list.

Internal staff want to be able to roam freely within and outside the office without losing network access. If they access the network from another user's PC, they want their own desktop arrangement of icons and resources to appear on-screen. They want electronic mailboxes capable of sending and receiving e-mail, faxes and assorted file attachments. They want tools to create elaborate multimedia documents and the means of sharing them with internal or external recipients.

External users include customers, potential customers, suppliers, business partners, consultants, shareholders and government agencies. Because the only universal access tool available to all of these groups is the web browser, all information intended for these audiences must be Internetbased. A more difficult decision is the depth of access granted. Easiest is the creation of a website with regularly updated information and e-mail feedback. At the next level, internal staff can be contacted in real-time, using video conferencing. Finally, there is comprehensive electronic commerce, with all of the above plus funds-transfer capabilities.

Along with this variety and depth of services, network managers have to provide security, reliability and acceptable levels of performance to the users. From a practical point of view, electronic file access security should at least be equal to physical file access security. A network login - or dial tone - should be available to any user at any time, even if some services are temporarily unavailable. File retrieval from a hard disk in a local server should be as fast as retrieval of the same file from the station's own hard disk. Upto-date network file backups should be found at all times both on-site and off-site.