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ch1.htm

Chapter1

Harnessing the Power: IntranetDefined

CONTENTSWhere the Internet Ends and the Intranet Begins

"But We Already Have E-Mail" (and Other Misconceptions)

Wresting Order Out of Chaos: Maximizing Value and OptimizingUtility

Some Intranet BenefitsEnhanced Efficiency

Enhanced Effectiveness

Content Is the Key

Is an Intranet the Answer? Some Intranet Criteria

An Intranet Checklist

Setting Intranet Goals

Getting Started

Summary

If you're reading this book, you probablyknow a fair amount about the Internet-what it is and how it works,its scope and its limitations. You may use it extensively in yourwork or at home, or you may rely on it for business research,interchange with peers, or simply for information or entertainment.

What you really want to know, however, is whether the Internetcan be used as a business or organizational tool-and, if so, howto make that happen.

Intranets offer the means to that end, by harnessing the raw powerof the Internet and applying it to individual organizational requirements.The real beauty of an intranet is its flexibility. There is nosingle formula or universal template, meaning that each organizationcan-and should-define, design, and use the intranet in the mannerthat best reflects its individual culture and supports its businessobjectives.

This chapter introduces the intranet concept and illustrates itsusefulness.

Where the Internet Ends and the Intranet Begins

An intranet is a self-contained, internal network linkingmultiple users by means of Internet technology. In effect, intranetsput a fence around the Internet's limitless territory, establishingcontrolled-access sectors within which users can communicate freelyand interact. Built and managed by companies or organizations(called sponsors), these networks reside on the World Wide Web,enabling cross-platform communications among authorized usersin real time.

Intranets as such are not a new idea. In fact, some of the mostcommonly used Internet applications-such as bulletin boards (BBSs)and commercial access services such as America OnLine (AOL)-are,in effect, large-scale intranets. That is, they link designatedgroups of users whose access to a given Internet site is determinedby password or other user-recognition mechanisms. For example,each AOL subscriber has an individual account for which a passwordis established to control access. The password system enablesusers to pick and choose Internet features that interest them,to contract for services on an individual basis, and to engagein a number of Web-based transactions. On the other side of theequation, the system allows commercial service providers to tracksubscribers' usage and maintain account and billing information.

In contrast to these broad commercial services, the intranetsdiscussed in this book are designed by and for specific user groups.They are smaller, more customized, and more sophisticated in termsof their features than the broader services. In addition, giventheir usage as an internal communications medium, intranets-notsurprisingly-tend to have more elaborate security mechanisms builtinto their designs.

The basic difference between general-access subscriber servicesand an organization's own intranet lies in the structure and intendedusage. Although the concept is essentially the same, the differencein one sense is that of mass versus class. Broad-based consumer-orientedservices tend to offer all things to all people for all reasons,while organization-specific intranets focus on a finite groupof people requiring a defined range of capabilities to achievespecific goals.

"But We Already Have E-Mail" (and Other Misconceptions)

A common mistake in considering intranets is to think of themas electronic mail. Conceptually, e-mail and intranet applicationsshare some common traits; for example, both offer a private, orcaptive, forum, and both enable the exchange of messages. However,an intranet is fundamentally different by virtue of its residenceon the World Wide Web. As a result, intranets are both more sophisticatedand more versatile than the relatively static electronic mail.

In essence, conventional electronic mail uses a central routingsystem to provide linear, sequential communication between twousers. Intranets, on the other hand, function using Internet technology.This means that multiple users can effectively interact in realtime, store and search document archives, collaborate on documents,and exchange graphics, audio, and video media. Depending on howan intranet is designed, users can "jump out" of anintranet and onto the "regular" Web for research orother purposes without noticing that they're moving from the intranetto the Internet.

Wresting Order Out of Chaos: Maximizing Value and OptimizingUtility

As discussed more fully in Chapter 35, "Creating Real-WorldApplications," a little discipline on the front end yieldssignificant long-term benefits for any organization consideringan intranet. There are numerous examples of major corporationsand associations that have made expensive mistakes by racing pell-mellto embrace a technology whose strengths and limitations they donot fully understand.

For example, in one case, the sponsoring organization badly underestimatedthe resources required to manage its intranet effectively overtime. As a result, internal message traffic quickly overcame thesponsor's capacity to respond, and posted content became firstchaotic and then stale. As a result, despite much initial fanfare,company users soon reverted to traditional patterns of interaction-telephone,fax, and haphazard hallway meetings.

In another instance, the sponsor-an international trade association-failedto consider extreme variations in users' technological capacityand local connectivity. The result was a state-of-the-art intranetthat could be used only by a select few-completely underminingthe original goal of democratizing the communications processby enabling equal access.

In still another case, a corporate sponsor wanted an intranetlargely for reasons of prestige. The CEO envisioned a showpiecethat outsiders would admire, as opposed to a management tool thatcompany insiders would actually use. This extremely hierarchicalcompany traditionally has discouraged interaction among its variousbusiness units and staff functions, and, as a result, informationis jealously guarded. Once the intranet was introduced, most userssaw it as an electronic outlet for disseminating official corporatecommunications. However, top management was appalled to discoverthat a few subversive middle managers found ways of using it tocollaborate, and quickly reconfigured the site to restrict informationexchange.

Each of these examples illustrates a mismatch between technologicalcapability and organizational requirements. At best, disconnectslike these mean lost opportunity; at worst, they can result inactual setbacks. Each of these organizations wasted time and money;in some cases, the effort significantly eroded credibility aswell.

Perhaps because the underlying technology is new-and in many respectsrevolutionary-many organizations fail to apply basic analyticdisciplines as they consider the pros and cons of intranets. Inthe most extreme instances, common sense seems to fly out thewindow, and managers abandon years of training and sound businessjudgment. While this can be exhilarating in the short term, itdoesn't make for productive use of this medium.

A far sounder approach is to consider or evaluate intranets inmuch the same way as any other major organizational initiative.No successful organization undertakes a new product introduction,a major marketing campaign, or a fundamental shift in businessstrategy, for example, without a clear understanding of goals,consequences, risks, benefits, and costs. So, too, should youor your company subject an intranet to the same exacting scrutiny.And while the technology may be revolutionary, many of the standardtools of business management should be applied.

Adopting a programmatic approach to establishing an intranet helpsthe sponsoring organization perform functions such as these:

Manage resources

Manage expectations

Plan ahead

Monitor progress

Measure results

Such an approach need not be unduly complex or time-consuming.Rather, it simply means that you should look before you leap.Applying common sense and business discipline at the outset greatlyimproves the likelihood of success in deploying the full powerof this medium.

Some Intranet Benefits

Intranets offer a range of benefits that fall into two broad categories:efficiency and effectiveness. In this context, efficiency meansimproving the mechanics of information exchange-overcoming logisticalobstacles to gather and disseminate necessary information in atimely manner. Effectiveness speaks to the organizational impactof enhanced collaboration and decision-making.

Enhanced Efficiency

Improvements in efficiency can be readily identified and lendthemselves to quantitative measurement. For example, many intranetsponsors report significant savings in out-of-pocket expenses(such as overnight mail, postage, or long-distance telephone charges).Other savings derive from diminished reliance on "produced"documents, such as company manuals, product brochures, or customerrelations materials, which can be disseminated electronicallyrather than printed and mailed.

Hidden in the efficiency equation are savings in staff time. Afully functioning intranet can drastically reduce "phonetag," swapping multiple document drafts, and other time spentin coordinating information-gathering. For example, intranetscan greatly expedite the peer-review process for technical researchpublications by enabling quick distribution and auto-mating thecompilation of responses and comments. In many organizations,an intranet centralizes the news clipping function; cutting, pasting,and circulating news articles is now done electronically froma single location, rather than literally at multiple company offices.

The sales force of one company uses its intranet extensively asa customer relations medium. Sales representatives access complementaryonline product information from clients' offices as they needit rather than carrying multiple slide decks or printed literature.For some of the company's more sophisticated products, the marketingdepartment has established an intranet sector specifically forcustomers, who use passwords to access the latest in relevantresearch and development (R&D) and product safety information.

A multinational trade association uses its intranet for, amongother things, organizing its complex schedule of meetings. Atany given time, this organization is conducting technical symposia,task force meetings, and business conferences-in addition to itsquarterly and annual plenary meetings, which usually attract hundredsof participants from around the world.

Each of these meetings has its own attendance list, agenda, briefingmaterials, venue management, logistical considerations, and expectedoutput. In the past, managing printed materials in support ofthese meetings required five full-time staffers and cost thousandsof dollars per year in reproduction and distribution. All of thesematerials are now posted to the association's intranet site, organizedto correspond to recipients' passwords.

Notification and scheduling of the association's meetings arealso handled via the intranet; a central calendar displays allscheduled meetings with the particulars attached so that memberscan see them all at a glance, see the details as needed, and registeronline.

Enhanced Effectiveness

Less tangibly-but at least as significantly-intranets can improvethe overall effectiveness of the sponsoring organization. Intranets,virtually by definition, encourage the exchange of informationacross traditional boundaries-both organizational and geographic.Properly managed, such enhanced exchange becomes the springboardfor substantive collaboration among previously fragmented sectorsof the sponsoring organization. Creative use of an intranet canexpedite an organization's evolution from a hierarchical, top-downmodel to a more nimble, interdisciplinary structure, by promotingcoordinated interaction.

One international law firm, for example, uses its intranet tostrengthen its environmental practice. The intranet permittedthe firm's environmental specialists to exchange-in a secure environment-informationabout current cases and emerging regulatory and legal trends affectingthem and to solicit their colleagues' counsel, quickly and privately.Bringing together practitioners in each of its offices enabledthe firm to capitalize on its collective expertise, improvingboth their attorneys' knowledge and their marketing leverage.

In one specialty chemicals company, the R&D and marketingdepartments reside in different countries, creating barriers tocustomer-responsive product development. This company used itsintranet to facilitate continuing interchange between the twodisciplines, establishing a system that includes regular updatemeetings online, R&D participation in customer surveys, androutine exchange of departmental news. This system has enabledthe company to factor customer requirements and preferences intothe product development process at the earliest stages. As a result,customers effectively have input into product R&D-meaningthat the company's products are better targeted and better received.At the same time, customers have better access to the company'sR&D expertise by means of a sales force that is better informedabout new technical developments.

An international public interest organization links together hundredsof chapters via an intranet that members use to keep abreast ofregulatory and social trends. Many of these chapters are small,with highly localized agendas and rely primarily on volunteerstaff. They lack the resources to monitor global issues, sponsorsymposia, or attend conferences. Their intranet offers local chaptersaccess to one another's experiences and strategies and helps themdistribute information across the full range of the membership.

Content Is the Key

All of these cases illustrate potential efficiencies that an intranetcan help achieve. At least as important, they point out a criticalfactor in getting value from an intranet: content. Every successfulintranet provides content-information-that users value.Of course, the nature of this content varies considerably, dependingon the individual user groups and their priorities. However, afew basic principles apply to any consideration of content, andintranet sponsors and users alike agree that the site's informationmust include such characteristics as these:

Relevance: This is in the eye of the user,not the sponsor. Organizations that use an intranet essentiallyas a passive forum for the party line may be disappointed in theirinvestment.

Timeliness: "Traffic jams"on intranets discourage usage; users quickly revert to conventionalcommunications when their e-mail and message boards are slow orunreliable.

Frequent updates: Many Web sites,public and private, suffer from static content, and interest andusage quickly drops. Intranets offer the capacity to consistentlyupdate changing information-a capacity that should be fully exploitedthrough automation and other features.

Accessibility: The best site contentin the world has little value if users can't get to it quicklyand easily. The point of the intranet is to make information available,and site design should take advantage of search engines and otherfeatures that improve user access.

In considering questions of content, it's important to keep inmind that intranets are uniquely user-driven and that user needsand preferences should be factored into the initial site designand engineering. As with any other construction project, it isalmost always more efficient to engineer in at the beginning thanto retrofit after the fact. Site features and functions that makecontent relevant, timely, and accessible-and allow for easy updating-shouldbe incorporated into site specifications on the front end.

Is an Intranet the Answer? Some Intranet Criteria

The key determinant of intranet value is your organization's informationneeds. As a very general rule, intranets are most useful to organizationsthat

Are geographically dispersed

Share common business objectives

Have common information needs

Value collaboration

As this very basic list suggests, the criteria for intranet utilityare both objective and subjective, logistical and cultural. Atthe very least, for an intranet to be meaningful, it must reflecta central focus-most often a common business or organizationalobjective shared by diverse individuals or groups.

It's important to keep in mind that not every organization needsan intranet. A small company, operating from a single location,for example, may exchange information more than adequately throughmemos, meetings, or at the water cooler. Such an organizationmay well use the Internet as a resource for gathering informationor intelligence, but probably doesn't need an intranet's addedpower and efficiency.

By contrast, a company with multiple sales offices or operatingdivisions in different locations, or a trade association or not-for-profitgroup with numerous members or chapters, may benefit significantlyfrom implementing its own intranet. Organizations such as theseconstantly strive to balance managers' needs for information thatis comprehensive and timely; they are burdened by logistical challengesarising from multiple time zones, incompatible computer systems,and erratic local phone service.

As a result of these and other barriers, critical decisions maynot have the benefit of full collaboration among key participants-orof comprehensive background information, equally available toall decision-makers. There may be gross inconsistencies betweenchapters or office locations in terms of their ability to disseminateinformation to members or staff. Similarly, widely dispersed organizationsoften experience needless headaches in relaying company data (suchas sales figures, financial projections, and so on) to headquarters.

At their most powerful, intranets help create and further a commonvision among disparate organizational components by empoweringthe individual. For many organizations, this is in itselfa revolutionary concept: achieving collective clout by distributing-notcentralizing-power.

Short of this "ultimate" vision for intranet usage,numerous uses may be less ambitious but offer significant benefits.For example, geographic dispersion alone may suggest the valueof a central archive of corporate policy materials, a regularlyupdated analysis of current news or other information, or automatedreporting of quarterly financial data, production statistics,or membership lists. Basic uses such as these help save time andaggravation by streamlining routine reporting and assuring readyaccess to standard information. Although a WAN can serve as sucha central depository for files and possibly share e-mail, a WANdoesn't necessarily mean intranet. A WAN doesn't have nearly thefull capabilities of an intranet, which, even in a basic design,overshadows a WAN in its ease and efficiency in performing numerousfunctions.

An Intranet Checklist

Intranets are, by definition, user-driven, and their design shouldreflect user needs. Therefore, a good way to get started is toidentify those needs within your organization that you hope anintranet can help you meet. This will help you establish realisticgoals, as well as a focus for your exploration of intranet options.Chapter 35 discusses these options in greater detail. However,the following sidebar may be useful in setting broad organizationalgoals for intranet applications.

OUTLINED GOALS FOR AN INTRANET

Structure: Understanding the organization's structure helps determine intranet utility in general, as well as which specific functions may offer the best value.Does the organization have multiple offices in different locations?

Are various staff functions (such as R&D, sales, human resources, law, engineering) resident in more than one location?

Is the organization essentially hierarchical? Is it distributed? Is it centralized? Is it decentralized?

Internal communications/information exchange: Understanding how the organization routinely exchanges information internally helps reveal gaps and barriers that an intranet can be used to address.What are the primary information sources-inside and outside the organization?

How is business information usually delivered (by e-mail, special delivery, telephone, meetings, or some other means)?

How are decisions usually made?

How is research usually conducted and shared?

External communications: Understanding how the organization interacts with its primary constituencies helps suggest opportunities for using the intranet to better meet their needs.Are there groups outside the organization (such as customers, shareholders, volunteers) with which it routinely interacts?

How does the organization keep them informed?

What information do they need? Want? Expect?

How does the organization receive and process information from them?

Barriers: A cold, hard look at barriers to effective communication helps identify organizational weaknesses and assign priorities to intranet development.What are the primary obstacles to efficient information exchange?

Are these barriers mechanical? Logistical? Cultural?

What is the impact of these barriers?

Resources: Evaluating available resources helps establish a realistic starting point for intranet design and implementation.What is the organization's current level of computer capability?

What resources-staff and contractor-are required to construct and manage the intranet?

What resources-financial, technical, and so on- are currently available?

Setting Intranet Goals

As suggested earlier, goals for an intranet may be modest or ambitious,highly specific or very broad. Regardless of what the goals maybe, what's important is that they be defined-clearly and in advance.As with any other major initiative, the sponsoring organizationshould ask itself some very basic questions before embarking onestablishing an intranet:

What do we want to accomplish? This isgoal-setting at its most basic, and it helps establish a targetand a focus for developing the intranet.

Why do we want to accomplish it? In effect,this is the devil's advocate question, forcing the organizationto consider the intranet in the context of its overall businessstrategy. (Hint: "Because the other guy is doing it"is not an acceptable answer.)

How do we expect to accomplish our goal?This question helps establish a framework for project planning,including leadership assignments, technical specifications, resourcerequirements, a timetable, and staffing patterns.

What will it cost? A true picture of intranetcosts should include estimates of both short-term outlay and expectedsavings over time.

How will we monitor progress? Intranetstend to evolve over time, and it is essential to build in mechanismsfor determining progress against expectations.

How will we determine success? As withany other initiative, intranet effectiveness is ultimately determinedthrough cost/benefit analysis.

At a more specific level, the sponsoring organization needs todefine the following criteria as well:

Who are the intended users of the intranet?The universe of potential users can be as broad or as narrow asthe organization requires. It may be defined as "every companyemployee," for example, or "all department heads."The user universe can also be defined along unconventional lines,such as "the mayors of all of our plant communities,"as an effort to create new alliances.

How do we expect our target audience touse the intranet? User interaction with an intranet will varyconsiderably, depending on the site's functions and the user'sneeds. For each user group, the organization should define specificutility and benefit to help assure design of a site that meetsthe needs and expectations of each group. For example, middlemanagers may find the greatest utility in a cross-platform messagingfunction, while sales reps may find a central archive most useful.

What does the audience need in order touse it? Having defined who will use the intranet for what purposes,the next step is to assess what's already in place in terms ofcomputer capacity, connectivity, and resident expertise. In somecases, for example, a given user group may require extensive basictraining, while for others, all that's needed is connectivityand a simple user manual.

Getting Started

The way in which an organization starts up an intranet initiativecan powerfully influence its success or failure. Because a primarygoal of most intranets is to encourage and facilitate collaborationacross organizational boundaries, it makes sense to start froma collaborative foundation. An intranet project provides a naturalopportunity for bringing together a range of relevant disciplinesto focus on a single goal, and the finished product almost certainlywill be all the better for it.

Impetus for creating an intranet can arise from almost anywherewithin an organization: executive row, a regional sales office,a volunteer recruitment center, a research lab, the law department,or the secretarial pool. Regardless of where it begins, like anyother broad organizational initiative, constructing an intranetrequires leadership, direction, and resources.

In other words, a successful intranet project needs

The input and endorsement of top management

A designated project leader with an explicitmandate

The tools and money necessary to do thejob

In addition, so long as leadership and accountability are clear,such a project greatly benefits from a multidisciplinary teamapproach, which helps assure that the organization as a wholereaps maximum value from its investment. A common mistake is toassign intranet development exclusively to an MIS department.While this choice may make sense on the surface, because of theintranet's technological underpinnings, the results will be disappointingif the technical experts operate in a vacuum.

A better approach is to form a project team that comprises a fullrange of potential users within the organization so that softwareengineers have the benefit of user input as they develop the intranet'sspecifications. One industrial concern used this kind of approach:A division president formed a six-member intranet team under thedirect leadership of his vice president of operations. Membersincluded senior representatives of the division's MIS, corporatecommunications, R&D, environmental affairs, law, and productmarketing departments.

Working together over a two-month period, this group developeda detailed work plan for the intranet, including explicit projectgoals, a user needs assessment, technical specifications, trainingcurriculum, and implementation schedule. Team members called onstaff within their own organizations to provide input, conductsurveys, and act as beta testers for a prototype intranet site;the MIS department designated a task group to design the underlyingarchitecture and direct the efforts of a software contractor.

The design of this intranet included not only its technical specificationsbut also a detailed staffing plan for traffic and content managementand for incremental roll-out to expand the site to include thefull range of users, in this case, all 350 division employeesat five locations. Full roll-out, originally projected over anine-month period, has occurred faster than anticipated-in partbecause of the site's popularity with users and the project team'sresponsiveness to their comments. The original project team remainsin place to provide oversight and quality assurance, evaluatingnew features and functions suggested by users and staying abreastof technological advances.

This division's intranet began with an idea, the designation ofa leader to carry it forward, and the creation of a team to makeit real. Along the way, success required planning, time, money,and, perhaps most important, a consistent commitment to the projectas a business priority. As a result of this division's efforts,its intranet has been adopted as a model for replication throughoutthe corporation, which within the next 12 months expects to befully online-well ahead of its competition.

Summary

Intranets offer tremendous potential for organizations that understandtheir potential and apply discipline and resources to achievingit. This potential is best met by defining goals clearly in advanceand with the support of a collaborative foundation. This collaborationat the beginning will help avoid building an intranet that isonly valuable to a select few employees. Knowing who the usersare before laying out plans will ensure that that intranet offersvalue in the form of content and ease of use among all its users.Although an intranet is never all things to all its users, understandingthe strengths and limitations of an intranet's audience will ensurethat it offers value to all users at various levels.

At each exciting turn, proceed with caution. Technology can beaddictive. Building the Mercedes of intranets is a waste of timeand much money if your audience has neither the knowledge basenor the need for such a sophisticated system.

No two intranets are the same, but as intranets and all theirpotential are unveiled in the coming chapters, keep in mind thatsuccessful intranets do share fundamental characteristics. Hereare the key determinants of an intranet's success:

Vision

Specific goals

Realistic expectations

A disciplined approach

User involvement

Follow-through

ch10.htm

Chapter10

Connectivity: Opening Up Your LAN

CONTENTSLAN Hardware ComponentsConnection Media

LAN Interfaces

LAN Software/Network Operating SystemsNetWare

Windows NT

Windows for Workgroups

LANtastic

AppleTalk

TCP/IP

Remote and Telecommuting Access to Your LANModems

ISDN

Setting Up the Network ServersFile Servers

Print Servers

E-Mail Servers

Communications Server

World Wide Web Servers

Network Connectivity Hardware

Summary

A local area network (LAN) at its simplest is comprised of twoor more computers connected with cables and network operatingsoftware (NOS), which allows all the computers to talk to eachother through the cables. Maximizing computer resources and makingfiles and applications easier to share are just some of the reasonsfor implementing a LAN. If you have two or 502 computer userscreating documents and spreadsheets that they want to print, youdon't need two or 502 printers. You can share as few or as manyprinters over the LAN as you choose. The same is true for theapplications that the computers use. Instead of buying 502 wordprocessing applications, you can buy one or two copies with theappropriate number of licenses for each user and share the singlecopy of the application over the network. Many businesses, governmentoffices, schools, colleges, and even some home computer usersutilize local area networks to get the most out of their availableresources.

Selecting the best LAN for a particular environment is a lot likechoosing a car. You must determine the basic functions you needand then work your way down to the details. For example, firstyou must decide what type of car to purchase. Once you determinethat a Chevy Suburban will meet all your needs, you then beginto consider the important, but somewhat minor details, such asthe color, type of interior fabric, and rear door options, rightdown to the type of radio you desire. The same is true for LANs,beginning with choosing the appropriate operating system and thecable connection, as well as choosing which services users mayaccess and at what time they may do so.

Assume that you need to purchase printers for a LAN. Considerthe following questions: How many users are on the network? Howmany printers are necessary for these users? Do any staffers needa personal printer to receive confidential figures? The type ofnetwork an office uses to share word processing documents acrossthe room is not necessarily the best network to share medicalCAT scan images across a hospital campus.

Determining your needs, the technology to meet those needs, andthen setting up a LAN can be a daunting task. In many cases, itmay seem as though you have too many options for some productsand services, while in other cases, you may have only an optionor two. Some background reading on today's trends and tomorrow'spredicted trends is worthwhile before you begin laying the foundationfor the LAN that will hold your intranet.

This chapter explores computer and network connections and thevarious hardware and software systems that are available for LANs.Additionally, I'll discuss the services these systems provideand how these services are useful for remote and telecommuteraccess.

Just as any good architect wouldn't design a "dream home"without getting to know her clients, you must first understandthe needs of your LAN clients before you begin designing the LANarchitecture. After fully accessing your users' needs, includingtheir capabilities, the function of their work, and whether thosefunctions might change in the future, you will be ready to startdesigning the LAN best suited for this group of clients.

LAN Hardware Components

Consider first what hardware comprises a LAN. Because the ultimategoal here is to connect all the computers via cables to form theLAN, exploring cabling options is a good place to start.

Connection Media

This section defines the physical cabling and connection techniquesused to connect computers into a network. You will find at leastone of these connection types in all LANs. In some cases, youwill find multiple connection/cabling types. For instance, youmay see fiber optic cables in one part of the LAN (perhaps a recentlyinstalled segment) and in another area find twisted pair cables.These two different media types cannot be directly connected.They are joined through a device that converts fiber optic signalsto twisted pair signaling, such as a router. You'll read moreabout routers later. For now, let's look at the connection mediain detail.

Coaxial Cable

Only a few types of cabling are used in LANs. We'll begin withcoaxial cable. The first generation of local area networks utilizedcoaxial, or coax, cable to connect computers. Coax cable includesa center wire called a conductor, which is usually made of copper.The center conductor is then surrounded by an insulating foamor plastic covering. A foil or wire braid surrounds the insulation.The entire cable is then covered in a plastic sheath. The centerconductor is the path for the electric signals (that is, data)on the network, while the foil or sheath is the ground for theelectric signals. An example of coax cabling is cable TV, whichgenerally uses this type of connection.

In fact, some local area networks are used for both cable TV andcomputer data. An advantage of coax cable is that the groundingfoil or braid protects the electric signals on the cable frominterference created by other electric sources. Electrical radiationfrom such sources as lights and air-conditioning units can corruptthe data signals as they travel down the cable. A disadvantageof coax is that the connectors can be difficult to install, andthe cable itself can lose some of its transmitting quality ifit gets squished or kinked, similar to the way a garden hose loseswater pressure. Coax cable is still found in many network environmentsbut is being replaced more often by twisted pair.

Twisted Pair

Twisted pair cabling is just that, a pair of wires each with aplastic coating that are twisted around each other and surroundedby an outside sheath. This is the same type of wire that bringsphone service into your home. Twisted pair cables are easy toassemble and not as sensitive to kinks as coax cable. The maindisadvantage of twisted pair cable is that it is more susceptibleto electrical interference from other electric cables and systemsand therefore has a lower transmission rate (that is, how fastthe data can travel through the wire) than coax cable. However,to improve the transmission rates, a series of better insulatedsheaths has been developed. These different categories of moreefficient cables are referred to by their level of insulatingproperties. Category 1 cable, or Cat 1, has less insulating properties,while Cat 3 cable has better insulation; Cat 5 cable has evenmore insulation. These various levels of insulation for twistedpair cables allow for transmission rates comparable with coaxcable, and in some cases, exceed the coax transmission rate.

Generally, the faster your LAN transmission rate is, the higherthe category cable you will need.

Fiber Optics

A fiber optic cable is a very thin rod of flexible glass fibersurrounded by a plastic coating. Instead of electrical signalstraveling down a wire as with coax or twisted pair cables, fiberoptic cable uses light to transmit data. The most basic formatof all computer "talk" is binary, a term representedin computer data as a 1 ora 0. Transmissions on a fiberoptic cable take the form of either "light is on" torepresent a 1 or "lightis off" to represent a 0.In contrast, coax and twisted pair cable must represent ones andzeros with varying electrical voltages on the wire; for example,+5 volts for 1 and -5 voltsfor 0. Since the fiber optictransmission is light, and not an electrical voltage, it is subjectto no electrical interference. This provides a much more reliabletransmission rate even in electrically "noisy" environments.The downside to fiber is that it is expensive to implement, sometimescosting several times what coax or twisted pair cabling costs.The skill level required to fabricate the fiber optic LAN cableis also greater. For instance, the glass fiber must be cleavedand polished just right for the fiber optic connection to workproperly. Twisted pair connectors on the other hand are simplyfastened to the cable.

Wireless

Wireless LANs use a Radio Frequency (RF) transmitter and receiverat each computer instead of a cable. Each computer broadcastsand receives data to and from the other computers through theair much in the same way a radio works. This may seem like theeasiest and most advanced way to connect computers to a LAN, especiallywith no unsightly wires and the ease of relocating workstations.Indeed many in the industry thought that wireless LANs would bethe wave of the future. However, some issues must be consideredwith wireless technology.

The first consideration is that computers using wireless LAN technologiesare broadcasting through the air to the other workstations onthe LAN, as well as to anyone else who may be "listening."The data sent and received could easily be picked up and decodedby someone other than the recipient for whom it was intended.The reverse is also true. Your LAN may be subject to unwantedaccess attempts from someone who isn't even in the building or"connected" to the LAN. If doubtful, just listen tothe numerous news reports of unauthorized persons acquiring cellularphone access codes who then use the codes to place thousands ofdollars in phone calls. Cellular phones and wireless LANs bothuse RF signals, and more people are listening than you might expect.

Also consider that the airwaves are cluttered with TV, aircraft,police, CB, and many other radio signals. It is plausible thatany of these RF sources could render your wireless LAN transmissionsless than reliable or altogether impossible. Despite these drawbacks,there may be a place for wireless LAN applications-for users whoface certain connectivity problems that would otherwise leavethem unconnected.

These four connection technologies-coax, twisted pair, fiber optics,and wireless-make up virtually all the LAN connection techniques.The type of cabling used in a LAN is determined by such factorsas environmental considerations, type of network operating system,transmission rate requirements, and even ease of maintenance.In the future, fiber optic cables will become more and more commonplacein local area networks. As the price of fiber optic connectionsdecreases, they will replace twisted pair and coax cabling withincreasing frequency, but coax and twisted pair will be with usfor a long time to come.

There is some flexibility in terms of which cabling you can usein your LAN design. For instance, some LAN technologies may requiretwisted pair exclusively, while others can run over several differenttypes of cabling. In the next section, we will look at the differenttypes of networks that run over these cabling systems.

LAN Interfaces

Having discussed the basics of LAN cables, now I will explainhow the cables actually connect to the computers. Typically thephysical connection to the LAN is made through a Network InterfaceCard (NIC). This card also is sometimes called a Media AccessControl (MAC) card. The MAC card is installed in the computermuch the same as a video graphics adapter card or a CD-ROM controllercard is. Some computers come with built-in network cards. A laptopcomputer can access a LAN with a PCMCIA LAN card or even througha parallel port adapter, which allows the computer to talk onthe network through the computer's printer port.

Again, the functionality remains the same whether the computersuse a parallel port adapter, a PCMCIA card, or a standard LANcard. The network card, in whatever form, provides a path forthe data to travel from the computer to the LAN cabling. Fourgeneral types of network interface cards are used today in localarea networks, and a few more new technologies are gaining popularity.The primary differences between them are in the way they "package"and transmit the data to the cable and the speed at which theytransmit.

Ethernet/802.3

The Ethernet, or 802.3, network is probably the most commonlyused network interface card. Ethernet networking was first developedby the DEC corporation. A variation on DEC's Ethernet technologywas defined by the Institute of Electrical and Electronic Engineers(IEEE) in the IEEE 802.3 standard. The Ethernet card can transmit10 million bits (a bit is a binary 1or 0) per second on the LANcable. Ethernet is sometimes called a 10 megabit per second (Mbps)LAN owing to this transmission rate. Recent advances in Ethernettechnology have produced the 100Mbps Ethernet LAN, which supportsthe growing number of applications that need greater transmissionrates.

Ethernet and 802.3 are sometimes used interchangeably, but thereare differences in the way the two standards package the data,called frames, to be transmitted on to the network. Inthis discussion, I will use the term Ethernet to describe the10Mbps network card whether it is sending DEC's Ethernet framesor 802.3 frames. Other frame types also can be transmitted withthe Ethernet card, such as 802.2 (another IEEE standard) and SNAPII.

All of these frames can be transmitted at 10Mbps over an Ethernetcard. The Ethernet network is a Carrier Sensing Multiple AccessCollision Detection or CSMA/CD system. This means that the Ethernetcards in the computers constantly listen to the network cableto determine whether other computers are using the line. If acomputer has data to send, the CSMA/CD system checks to see whetherthere are any current transmissions. If there is no activity onthe line, the computer can transmit. If the line is busy, thecomputer waits until the line is free. If two computers talk atthe same time, a collision warning is sent out on the network,and all the computers time out for a fraction of a second beforetrying to transmit again. The speed of the time-out and retransmitfunction is on the order of milliseconds, and typically, you willonly experience delays of a second or so even in a very busy network.Ethernet is somewhat like an open discussion: If you want to talk,you need to wait until no one else is speaking.

Ethernet uses either a bus or a star topology. The bus topologyis essentially a term that describes a single-cable LAN with allthe computers connected to it. It is very easy to implement. Thebus topology comes in two versions-thin coax cable and thick coaxcable. Ethernet was originally implemented with thick coax cable,but the development of thin coax, also called "cheapernet,"proved much easier to install because of its thinner, more flexibleproperties. The coax cable bus topology is a single cable thatruns throughout the office or whatever area is being networked.You simply run the cable past each computer, add a connector tothe cable, connect it to the computer and continue on with thecable to the next computer. The advantages of a bus cabling topologyare that you only run one cable and that the coax cable used inthe bus network is more resistant to electrical interference.The disadvantage of the bus network is also the single cable.If the single cable becomes damaged in any one place, all theworkstations on the LAN will be affected.

The star topology uses twisted pair cable. In this topology, eachcomputer has its own twisted pair cable that connects the Ethernetcard to a connection port on a hub or concentrator, as shown inFigure 10.1. Inside the hub is the equivalent to the single coaxcable which connects all the hub ports. Technically speaking,the twisted pair LAN is still a bus, but from the actual layoutof the cable, it looks to be a star. The advantage of using astar topology is that if any one cable that runs to a computeris damaged, the other computers can still communicate over theLAN. The only real disadvantage is that you must run a separatecable for each workstation. Many LAN designers feel that the benefitsof the twisted pair star far outweigh the disadvantages, and thetwisted pair hub approach to Ethernetworking is very widely used.

Figure 10.1: An Ethernet network of the star topologytype.

Token Ring

Token Ring was developed by IBM and is found mainly in mainframeor IBM AS/400 environments. Token Ring comes in two differentversions: the 4Mbps and the 16Mbps version. As with Ethernet,Token Ring has an IEEE equivalent in the 802.5 standard, but theydiffer slightly in the way they package data into frames for transmissiononto the network. The IBM Token Ring uses twisted pair cablesand is set up in a star topology with each computer connectedto a hub or concentrator. The 802.5 Token Ring also operates overtwisted pair cables and can be in a star topology or an actualring where each computer is connected to the next and the lastcomputer is connected back to the first to close the ring, asshown in Figure 10.2. Unlike Ethernet, the communications overthe Token Ring network are moderated by means of an electronictoken-hence the name. Each computer on the network mustwait to transmit data until it receives the token. Using thismethod, there is no possibility of data collisions created whentwo computers "talk" at the same time.

Figure 10.2: A Token Ring network.

ARCnet

ARCnet was developed in the late 1970s by the Datapoint Corporation.ARCnet uses a combination of Token Ring and Ethernet known asa token bus. The IEEE standard for token bus is 802.4.ARCnet transmits data at 2.5Mbps and can run over many differentcables, including twisted pair and coax cables. The ARCnet technologyis not used often in office networks but rather in factory andwarehouse LANs. The ARCnet network is very forgiving in termsof the quality of the connectors used and in how far you can runthe cables. Ethernet and Token Ring cables' limitations are measuredin hundreds of feet as where ARCnet cable runs may exceed 20,000feet. Due to the lower transmission speeds, many administratorsfaced with implementing a new network choose faster technologiesthat cost the same to install. In addition, many data productmanufacturers do not provide ARCnet network equipment. For thesereasons, I do not recommend ARCnet as a good solution for contemporaryLANs.

FDDI

The Fiber Distributed Data Interface, or FDDI (pronounced "fiddy"),networking technology is a product of the American National StandardsInstitute. It is a 100Mbps LAN that uses a token-passing accessscheme with a dual ring topology. The FDDI LAN has two fiber opticcables that connect to each workstation. This dual cable implementationprovides redundancy in the event that one cable should fail orbecome disconnected. The FDDI network connection comes in twovariations, as illustrated in Figure 10.3. The Dual Attached Station(DAS) connects to both fiber optic cables. The Single AttachedStation (SAS) connects to only one of the FDDI cables.

Figure 10.3: A FDDI network.

Obviously, the SAS connection does not have the redundancy a dualstation has. A FDDI LAN has many advantages. Because it includesno electrical signal in the cable, the data on a FDDI networkis immune to interference from lights and other electrical sources.The data traveling down the fiber can't be "tapped"or monitored because the signal is light and doesn't radiate fromthe cable where it could be "picked up."

Indeed this security feature has sold FDDI into many governmentand commercial environments where security is a primary concern.The speed of transmission is also a major plus.Although with thenew 100Mbps Ethernet technology, speed does not distinguish FDDIexclusively. FDDI also can be used as a Metropolitan Area Network(MAN), and some phone companies have begun marketing the FDDItechnology to create what amounts to very large LANs for telephonecustomers. The main drawback of FDDI is the cost of implementingit over fiber optic cables. However, FDDI can be run over twistedpair cabling. In this environment it is called CDDI (Copper DistributedData Interface).

ATM

Asynchronous Transfer Mode (ATM) is still largely uncharted territorybecause the technology is still in its infancy. The ATM implementationstandards are still being defined. ATM is delivered over fiberoptic cabling and has transmission speed capabilities in the 155to 600Mbps range. ATM is a cell-switching transport service thatpackages data transmissions in small, fixed-size groups insteadof variable-sized packets as in Ethernet or other LAN (and WAN)protocols. Using small, fixed-size cells over fiber optics allowsfor incredible transmission speeds. Some companies, includingIBM, are rolling out ATM LAN applications, but for the most part,the cost of ATM is still prohibitive for most LAN applications.There are some ATM implementations in place supporting Wide AreaNetworking (WAN) and hospital or engineering labs that supportmedical imaging or computer-aided design applications. ATM isthe future of LAN-based applications and services that requiregreater and greater transmission speeds.

Increasingly, more and more video teleconferencing, distance learning,voice communications, television, and graphic imagery will berunning over local area networks, and we will need the transmissionrates that ATM can provide. This kind of speed is crucial to supportingvideo and imagery data.

We have covered many different aspects of local area networking,including what kind of cabling and types of media access techniquescan be employed to provide connectivity. As a rule, transmissionrates of current LAN technologies are always being pushed to thelimits as more and more speed-intensive applications find theirway on to our computers. We will rely more and more on our computersfor making voice calls, conducting videoconferences, and makingbank and shopping transactions. The local area network will betasked increasingly with these transactions.

In planing for the future, you must weigh the benefits of leading-edgetechnologies against the costs and decide whether you need thecapabilities they bring. If you know that you will have to supportcomputer design and modeling applications or video on the LANin the next two years, you may want to look at ATM. Even thoughit will be more expensive initially, it may be cheaper in thelong term versus installing an Ethernet only to dismantle it andupgrade to ATM later. We have discussed the prominent technologies,but by no means every type involved in local area networking.For the most part, these discussions cover a little of the past,the present, and the future of the local area network.

Any of these LAN networking techniques can be used in the buildingof an intranet. You must keep in mind, however, that you willbe connecting LANs and that compatibility and end-to-end functionalityis an issue. For instance, if you spend a tremendous amount ofmoney installing 155Mbps ATM LANs in your offices to move hugeimaging files around but can only afford a relatively slow T-1(1.54Mbps) from the phone company to connect to your ATM LANs,you will have a bottleneck in your intranet, and the money youspent on ATM may be a waste. As with many things, your intranetmay only be as fast as its weakest link.

LAN Software/Network Operating Systems

Now that we've covered how to connect all these computers andprovided a way for them to talk to each other, we need to givethem something to talk about. This section explores some of thedifferent network operating systems (NOSs) that I mentioned earlierin this chapter. A network operating system performs the samefunction for the network that a Disk Operating System (DOS, UNIX,Mac, O/S, and so on) performs for a computer. The computer's operatingsystem is the director of the computer's resources. It takes thedata entered at the keyboard, displays it on the monitor, andthen reads and writes files on the disk drives. When a file isprinted, it feeds the data to the printer port. The computer operatingsystem knows just where all of these resources are stored, howto identify the resources, and how to access the resources. Networkoperating systems perform the same functions but for many computersacross a LAN. As mentioned previously, it's likely a group ofusers will share a printer, an application, or even a fax machine.To logistically ease the backup procedure, files generated byall the users usually are stored in one place on the network.The files necessary for the sales department to access are differentfrom the files the accounting department needs, so certain users'access should be restricted, while setting permissions for otherusers will be necessary. Each of these procedures is directedthrough the network operating system.

The kinds of services you will find in a local area network, suchas shared directories and printers or e-mail, varies from LANto LAN. The primary services computer is called a file server,and all LANs have one. A file server is usually a computer muchthe same as all the other computers across the LAN. The file server,however, usually has a faster processor than the computers itserves, as it must "serve" the system's resources toall the computers. In addition to the basic file and printer sharingcapabilities, a LAN can provide e-mail, group scheduling, WorldWide Web access, and remote access. Providing these services tousers often is as straightforward as loading software on the LAN.

Some of the more popular network operating systems are Novell,Banyan Vines, LANtastic, AppleTalk, and Windows NT. All of theseoperating systems provide the basic local area network services,such as sharing printers, directories, and files; they also allowaccess to other common resources, such as modems and faxes. Inaddition to the basic features, specific network operating systemsoften have advanced features or capabilities particular to thatsoftware. These more specific features may determine which NOSis utilized for each LAN. Some of these network operating systemsare examined in more detail in the following paragraphs.

LAN operating systems basically fall into one of two groups. Thefirst group is client/server. The client/server environment isdistinguished by having one or more computers run software thatprovides the services for the LAN (for example, a file serveror a print server). In the client/server group, LAN computersare loaded with software that allows them to access the serverapplications, hence the term client. The other class of LANs arecalled peer-to-peer networks. In a peer-to-peer network, any computeron the LAN can be serving applications or acting as the printserver.

If you are planning to set up a LAN for 10 users so you can sharefiles and printers, a 10Mbps Ethernet running a peer-to-peer operatingsystem would be fine. If you are planning on getting 300 engineering,accounting, and management staff all connected to common resources,some with access to payroll or credit card accounts, you mightconsider a client/server operating system running on a FDDI network.

NetWare

NetWare is a network operating system designed by Novell, Inc.It actually is based on a networking technology developed by theXerox Corporation called the Xerox Network System or XNS. NetWarefirst appeared in the early '80s with its early versions providingbasicconnectivity for desktop personal computers, which were justbecoming popular. The LANs of that time were small, usually consistingof all the same type of computers with little requirement or atleast support for PC to Macintosh or UNIX system access. Typically,the office PCs needed to share files and printers, and interconnectivitybetween dissimilar computers or even security and auditing featureswere unheard of in LAN network operating systems. NetWare hasundergone many revisions since then and is now a dominant forcein the LAN industry, holding perhaps as much as 70 percent ofthe market share. NetWare is a client/server LAN system and cansupport Macintoshes.

The advantage of Novell is the capability to support many usersand services. You could use Novell to connect different officesacross the hall or across the country. Novell NetWare has thecapability to support many different types of computers includingDOS/Windows, Macintosh, and UNIX systems. NetWare also has optionsfor accessing the local area network by dialing in with a modemand for setting up the TCP/IP protocol for access to the Internet.It is ideal for mid-size to large size LANs and LANs with alldifferent types of computers. The disadvantage of NetWare is thatit takes a while for both the LAN administrators and users tobecome proficient in using all this functionality. NetWare canbe run over Token Ring, Ethernet, ARCnet, and FDDI LANs.

Windows NT

Microsoft's Windows NT is the latest LAN operating system to appearon the market. Windows NT is a client/server operating systemdesigned to support LAN connectivity in much the same fashionas NetWare. Windows NT has many of the same features that NetWarehas and is NetWare's biggest competitor. Windows NT supports dial-inaccess to the LAN and Internet access support. Advantages of WindowsNT are that it is fairly easy to become proficient in, and inmany cases, it is less expensive. It doesn't have the long-termtrack record that many of the other operating systems have, butit is enjoying a very enthusiastic and growing loyal customerbase. Windows NT can also be run over Token Ring, Ethernet, ARCnet,and FDDI LANs.

Windows for Workgroups

Windows for Workgroups is Microsoft's peer-to-peer networkingenvironment. This NOS is good for small LANs that need to providevery basic connectivity and services, such as shared directories,printing, and application serving. Windows for Workgroups is veryinexpensive compared to client/server LAN packages but again doesnot provide specifically for the more advanced features, suchas security auditing and tracking that the larger client/serverLANs offer. Windows for Workgroups runs over Token Ring, Ethernet,ARCnet, or FDDI LANs.

LANtastic

LANtastic is a peer-to-peer LAN that actually uses some of theNetWare protocols to communicate over the network. This is anotherNOS that is good for small LANs. Basic connectivity and servicessuch as shared directories, printing, and application servingare supported. LANtastic is inexpensive and easy to set up comparedto client/server LAN packages but again, does not provide as manyservice options as the client/server LANs, or even as many asWindows for Workgroups. LANtastic runs over Token Ring, Ethernet,ARCnet, and FDDI LANs.

AppleTalk

AppleTalk is a peer-to-peer LAN that is specific to Macintoshcomputers. AppleTalk is good for small Macintosh LANs. It supportsbasic connectivity and services such as shared directories, printing,and application serving. AppleTalk has no support for systemsother than Macintosh. It is inexpensive because it is part ofthe Macintosh computer operating system and is easy to implement.

TCP/IP

TCP/IP is the "language" of the Internet. It is a networkingtechnology developed by the United States Government Defense AdvancedResearch Project Agency (DARPA) in the 1970s. It is most commonlyemployed to provide access to the Internet but can be and is usedby many people to create a LAN that may or may not connect tothe Internet. In many aspects TCP/IP is a client/server-type LAN,but many manufacturers of TCP/IP software have applications thatallow the "clients" to serve files or even applications.

TCP/IP has, from an architectural standpoint, some of the samequalities as NetWare, but TCP/IP is truly an open systems protocol.This means that no one manufacturer creates the product-any computerrunning TCP/IP software can connect to anyone else who has TCP/IPsoftware (provided the user has an account and security permissions),regardless of who made the particular version of software. Forinstance, the FTP Software company's version of TCP/IP, calledPC/TCP, is completely compatible with the Wollengong company'sversion. Novell also makes a version of TCP/IP software to provideInternet access functionality for their client/server NetWareLAN, and a version of TCP/IP is completely compatible with thePC/TCP software from the FTP company. TCP/IP is an ideal intranetworkingprotocol. If you have two different type of LANs such as WindowsNT and NetWare which do not "talk" to each other, youcould run TCP/IP in addition to the NT and NetWare software toget inter-operability. TCP/IP runs over all networks, includingToken Ring, Ethernet, ARCnet, and FDDI LANs.

These are the more popular LANs in use today. Support for thesenetworks is widespread with many publications, Internet discussiongroups, and certification programs for those who install and maintainthese networks. Novell and Microsoft have established CertifiedNetwork Administrator and Certified Network Engineer programs.

Other LAN operating systems include

DECnet, Digital Equipment Corporation'sclient/server LAN package

XNS, the Xerox's network systemthat is the basis for Novell client/server LAN NetWare

The Open Systems Interconnect,or OSI LAN system, which is another open systems LAN architecturethat provides the same type of interoperability that TCP/IP offers

Microsoft's LAN Manager, a NOS designedto run with IBM's OS/2 operating system

The Banyan Vines network, a TCP/IP-basedLAN package

None of these other LAN systems have had the impact that NetWare,TCP/IP, and Windows NT have had on local area networking. Thereare certainly large numbers of DECnet or Banyan Vines LANs beingused today, but many consider the serious client/server LAN tobe a "neck-and-neck" contest between NetWare and WindowsNT.

Remote and Telecommuting Access to Your LAN

I have described some of the services found in the local areanetwork, such as the file serving, print sharing, or e-mail inbrief, and I have put these services into the context of a localenvironment, such as an office. One of the services mentionedis the remote access of the LAN resources-in other words, dialinginto the LAN with a modem from a remote location to share filesor perform administrative tasks. The idea of remote access haslong been a part of LAN services, but with recent advances inthe speed of modems, new protocols such as PPP (Point-to-PointProtocol), and phone company services, such as Integrated ServicesDigital Networking or ISDN, remote access functionality has improveddramatically. Just a few years ago, a remote user would dial intoa computer on the LAN at 2400bps and log into the file serverfrom the computer on the LAN. The remote user could only see textdisplayed through this kind of link, and the types of transactionsperformed were limited because the connection was very slow. Today,a remote user can log into the LAN and perform virtually all typesof transactions as if he were actually in the office. In thissection, we will discuss these different types of connectionsand how the LAN can be expanded or opened to provide remote accessservice.

Modems

Modems have been used in computer communications for many yearsnow. A modem is a modulator/demodulator. It takesthe binary ones and zeros that all computers "speak"and turns them into a series of audible tones that can be sentover standard phone lines. (Standard phone lines are also referredto as plain old telephone service or POTS lines.) Modems are phonesfor computers, and they basically work in pairs just as phonesdo: the modem you are using to call and the modem that is answeringyour call. You can connect to any computer in the world that hasa modem, just as you can call any house in the world that hasa phone.

A modem is connected to a computer's communications port, knownas a comm port (such as COM1 or COM2), and also plugs intoa telephone outlet the same way a phone does. Modems are alsoavailable as a card that plugs into the computer in a manner similarto a LAN card. The computer is loaded with software, such as Datastorm'sProcomm or PC Anywhere, which operates the modem and allows youto dial up the modem (that is, computer) with which you wish tocommunicate. Modems modulate and demodulate the data bits (1sand 0s) very slowly. If yourecall, the Ethernet transmission rate is 10 million bits persecond. The maximum modem transmission rate over phone lines is28,800bps. This limits the type of transactions that can be performedover a modem, particularly in terms of accessing LAN servicesthat are designed to be served at much faster speeds.

If you are retrieving a business letter from the file server toyour home computer with a modem, the transmission rate is probablyacceptable. If, on the other hand, you are trying to use the LANword processor application on the file server through a modemconnection, the transmission rate will be slow enough to makethe process a very tedious venture. Modems are very inefficientfor computer transmissions. All the modulating and demodulatingtakes time to perform; this is one of the reasons modems mightnever be able to exceed 28.8Kbps.

Traditionally, remote users have used a modem to access the on-siteLAN by calling one of the LAN's computers, which has modem forsuch a purpose. This computer is called a communications serveror gateway, and it gives the remote user access to theLAN by using the comm server's LAN software and network connection.The comm server is really just another LAN workstation, exceptit has a modem and modem software on it. One of the disadvantagesof this type of access is that you must first load any files youwish to send to the file server on to the comm server throughthe modem connection and then from the comm server to the fileserver.

The file server doesn't recognize your home computer through amodem connection as a LAN client. You must use the comm serverto act as a LAN client on your behalf. You could set up the fileserver as the comm server to gain direct access to applicationsand files, but this bypasses the client-to-server connection process(called a login) and poses definite security risks. Youmay not have network security concerns per se, but it is stilla good idea from a network administrator's point of view to havea dedicated comm server.

As you may already have imagined, it can become a bit of a headachesetting up a comm server that can support dozens or even hundredsof dial-in users. The idea of one LAN workstation with a few modemsattached to it is functional for a very small LAN, but would benothing short of a nightmare for a LAN that supports 120 dial-inusers.

Another approach to dialing in with modems is the modem bank andterminal server. In this scenario, the comm server still usesmodems, although they are modular or rack mountable in designversus a desktop or internal PC type modem. This allows you toadd new modems in an orderly fashion as the demand grows. Themodular modems are mounted in an equipment rack where each isconnected to a phone line and to the communications server, whichfor this type of connection is actually a device called a terminalserver. The terminal server is not a computer per se as inthe earlier scenario. The terminal server does provide accessfor the incoming call to the LAN, but it also adds the abilityto negotiate a more sophisticated type of connection.

In the modem bank/terminal server type of connection, the computerdialing in can be assigned an actual LAN identity or address.This allows the computer to converse directly with the LAN serversand resources. This method of connecting is called remote clientaccess because the dialed-in computer becomes a LAN clientas if it were actually on the LAN. This type of connection isnegotiated using a protocol called PPP or Point-to-Point Protocol.Both the terminal server and the user's home computer must havethe PPP software to establish this connection. Although the speedof the connection is still limited to the transmission rate ofthe modem, PPP is still a more "graceful" connectionand is far more streamlined than having a comm server act as a"middleman" in the connection.

ISDN

You may have heard of the phone company's ISDN, or IntegratedServices Digital Network. This type of networking provides a digitalor binary (all 1s and 0s)transmission service that can be dialed just as a standard phone(POTS) line can be dialed. The advantages of ISDN for LAN accessare extensive: Your computer doesn't have to have its binary "talk"modulated into tones for transmission over phone lines as modemsdo. The data stays digital from your computer through the phonelines to your LAN. The slowest ISDN speed is 64,000 bps or 64Kbps.The higher ISDN speeds exceed one million bps. ISDN generallycomes in two forms. The first is the Basic Rate Interface or BRI.BRI is two 64Kbps channels called bearer or B channels.Both these B channels can be used together to form a 128Kbps connection.The second type of ISDN service is the Primary Rate Interfaceor PRI. A PRI is a 1.5 million bps line (1.5Mbps) that is madeup of 23 B channels.

ISDN requires different equipment than POTS lines. A modem willnot work with an ISDN circuit, because the ISDN service is alldigital, whereas the modem is designed to turn digital "talk"into sounds or analog "talk." The type of equipmentused to access ISDN depends on whether it is a BRI or PRI service.For the BRI service, you need a terminal adapter or TA. A TA connectsyour computer to the ISDN line. As with modems, you also needsoftware to dial over the ISDN service. PRI service, on the otherhand, is a more sophisticated and complicated kind of servicethat requires something called a channel service unit,or CSU, to help sort out the 23 channels of data that makeup the PRI service.

The ISDN access technique at it simplest is much the same as itwould be with a modem connection. One ISDN-connected computerdials another ISDN-connected computer-only the speeds involvedare much faster. You can buy an ISDN card that installs in thecomputers or an ISDN TA that sits on the desk just as a modemdoes. This is a typical implementation for simple connectivitybetween computers. Using ISDN, you would dial directly to thefile server, which would also be equipped with an ISDN card toaccess services in this way, but the number of incoming callsto the LAN would be limited by the number of ISDN cards in yourserver.

A more secure and functional method for connection to the LANwould be the ISDN terminal server solution. This solution alsouses the Point-to-Point Protocol, but the phone line is the higherspeed ISDN. An ISDN terminal server with PPP provides dial-inusers with the feel of actually being directly connected to theLAN. The response time in accessing LAN resources is greatly improvedwith this solution.

The use of ISDN is expanding every day. In previous years, onlyvery expensive digital services were available from the phonecompanies, and companies leased the digital line on a full-time(24 hours a day) basis whether they used the line or not. Theleased 56Kbps is an example of the full-time digital line. ISDNhas brought users the "dial on demand" services thatallow them to dial the connection when they want it and pay peruse. Even the most basic ISDN service (BRI or 128K circuit) providesa better transmission rate than the slower, more expensive 56Kbpsservice.

Setting Up the Network Servers

There are many things to consider in setting up the network. Afteryou have determined the number of users and what type of LAN technologiesyou will use, you must select the types of hardware (that is,which computers, cables, and network cards). A fair amount ofthese decisions can be based on cost, but you must also considerthe reliability of the equipment. If your file server keeps breakingdown, it is hard to justify having saved $300 on the purchasewhen you've spent twice that much time fixing it. Furthermore,as soon as your users are acclimated to the LAN and using itsservices, even the shortest downtime will generate tons of phonecalls to your office. Spending a little more on better equipmenthelps reduce problems in the long run.

You must also decide how to route the cabling through your facility.You could simply lay the cables around the floor, but this isn'tpleasant to look at and will probably cause problems with peopletripping over the cables and disconnecting them. You could placethe cables up in the ceiling, but that could also cause problemsbecause this puts the network cables close to electrical cables,possibly causing data transmission problems. If a lot of networkcables are necessary to connect all your computers, you may notbe able to trace or isolate a cable problem if the cables arejumbled together.

Some advanced planning is in order for the layout of the cabling.You may want to have a structured cabling system installed. Astructured cabling system is a generic cabling system that canbe used to connect data video and voice lines throughout yourfacility. It is a little more expensive for a LAN implementationonly, but if in the near future you'll need to install a new phonesystem to support your growing business, you may be able to killtwo birds with one stone and install a cabling system that supportsboth.

After you have decided what your users need to do and what LANsystems support those requirements, you may want to have an independentconsultant look at the design to confirm your plan. A few hourstime spent with someone knowledgeable about LANs and the applicationsthat operate over them may be well worth the money. At the veryleast, you can confirm your LAN design skills, and if your designis incomplete, you have the opportunity to gain some valuableinformation.

After you are satisfied that your LAN design is adequate, youmust evaluate the three issues surrounding the actual implementationof the LAN. The first is determining whether you really have theresources "in house" to perform the installation ofall the network cards and cables. The second is setting up thesoftware on the servers and client workstations and getting themto work together. The final issue is the administration of thenetwork. Are you prepared to handle all the trouble calls andrequests for additional services?

The server must have routine maintenance check-ups, and data filesmust be backed up periodically in the event of a system failure.All this day-to-day operations "stuff" is a full-timejob and then some. You may very well want to contract out theinstallation, integration, the administration, and even the LANdesign to someone with experience in networking. Many organizations,both commercial and in government, do just that.

You could have the administration portion of the network staffedby contractors until you have hired a few people into your staffto take over. When selecting contractors for the installationand administration of your network, make sure they have experiencewith the network you are installing. The same applies for thoseyou hire as LAN support technicians. They should be able to answerdetailed questions and demonstrate a clear understanding of theLAN systems you have implemented. Never allow one person to becomethe sole caretaker, administrator, or technician for your network.If that one person leaves your organization or if that personis away on vacation and the network goes down, you may find yourselfwith a network that doesn't work, and no one who knows what thecause might be.

At a minimum, your network will have one server (even in a peer-to-peernetwork), which will be hosting the applications or files. Moreoften than not, a LAN has several servers to provide all of theservices your users will require. You will more than likely beusing an Intel-based computer (this would be the kind of computerwith the Intel processor chip in it) and running DOS and Windows.The specific LAN software you select will have specificationsfor the minimum system requirements, and it is recommended thatyou exceed them where possible. If the LAN package requires a486 66MHz computer with 8MB of RAM, you should probably go aheadand get a Pentium 90 with 16MB RAM, just to be on the safe side.

Network servers can be located anywhere on the network; however,the servers should be located off the beaten path. That is tosay, you shouldn't have the servers located where people are goingto be bumping into them or setting their morning coffee on topof them. These machines are the most important pieces of yourLAN. You'll want to purchase a good uninterruptible power supply(UPS) to protect your server against power surges or outages.Locate the servers in a cool, environmentally controlled room.You may need air conditioning if the room has a great deal ofequipment and is warm or not well-ventilated. In large LANs, roomswith many servers are referred to as server farms, and they oftenhave not only air conditioning systems, but also humidity controland fire control systems.

Servers need to have their data backed up regularly. This typicallyinvolves a cassette tape-like system that is installed in theserver, similar to a floppy or CD-ROM drive. A copy of the serverfiles are made with the tape backup every day or every other daydepending on the amount of data being created. If you are sellingwidgets by the thousands every day and the accounting for thebusiness is on the LAN, you want to back up the accounts payableand receivable, as well as the inventory database every day. Thenonce a month, back up the entire server, applications and all.In fact, make two copies of your backups. Store one in the LANadministrator's office and the other off site. In the event ofa fire or other disaster, having a backup at your house will savea lot of suffering. Some administrators deposit monthly serverbackups in safe- deposit boxes at two different banks in additionto the two office copies. If you are serious about your LAN, takeyour backups seriously.

The next few sections contain some information on the differenttypes of servers you will find in a LAN. They are not necessarilydifferent computers. The file server may also be the print serveror the e-mail server. The different servers are listed by theservices they perform to help define the roll they play in theLAN.

File Servers

The file server is the heart of the LAN. It has the applicationsthat the users need and the files that are shared. It is usuallydivided into sections that the users can access, such as theirown directories or shared directories, and the sections that arerestricted to administrative access, such as security directoriesand operating system files. The computers with client softwarecan view a list of servers on the network and select the one towhich they will connect. Often each department, such as engineering,accounting, or sales, has its own server. Users may or may nothave connection or login privileges on every server. Someone inengineering may have no reason to have an account on the accountingserver. The servers also need to be serviced periodically. Runninga disk optimizer program or utility to check the health of thedisk is recommended. Norton Utilities is an example of a systemdiagnostic/preventive maintenance package that is widely usedon DOS-based computers. Many network operating systems have theirown disk maintenance programs.

Print Servers

Print servers are the servers that have a printer or printersattached to them. In a LAN environment, a computer prints to anetwork printer over the LAN cabling. You could make the fileserver also the print server, but you'll want to locate the fileservers some place out of the way. You'll need to have a serverthat will satisfy the printing requirements located near the users.A print server is just that. The software in the client computersredirects the print jobs that would normally go to the LPT portout on the user's computer out to the network print server.

If your network is small-say, 20 users-you probably just needone print server with one printer. If your network is sixty peopleon two different floors, all printing documents and some printingcolor slide presentations, you probably want three or four printservers with five or six printers. A print server accepts theprint jobs in the order in which they are sent and stores thefiles. This is called spooling a job. As soon as the printercan accept a new job, the file is sent out the print server'sLPT port to be printed.

E-Mail Servers

E-mail is quickly becoming the way businesses communicate. Ithas in many cases replaced voice mail. E-mail comes in two basicformats: the version that is designed to work within your LANusing your LAN's software protocols (such as Novell's GroupwiseMessaging System), and a TCP/IP based system that allows Internete-mail as well as internal LAN mail. The Simple Mail TransferProtocol, or SMTP, is an example of the TCP/IP e-mail service.The e-mail found on the Internet is largely SMTP mail. Many LANoperating systems such as Novell's Groupwise Messaging have add-onpackages that allow access to Internet e-mail by creating gatewayservices. A gateway takes one kind of application, such as theGroupwise Message e-mail, and converts it into the SMTP e-mailformat so it can be sent out to the Internet. The e-mail servercan be located on the file server, consolidating the backup process.

Communications Server

We've talked about users dialing into the network to access services.The communications server is the one that provides that functionality.Again, this type of server for dial-in services is only reallypractical for the smaller or mid-size LANs. Larger LANs may requirea modem bank and terminal server for the more sophisticated accessdiscussed earlier. However, a comm server can provide a very usefulservice in addition to dial-in support-namely, dial-out. You maywant to fax documents right from the desktop across the LAN throughthe comm server. With a fax modem attached to the server and somefax software, your users never need to walk over to the fax machine.The reverse is also true. A user can receive faxes into his orher own mailbox through the comm server. Support for this typeof functionality varies with the different LAN operating systems,so you may want to make this an element of your LAN software selectionprocess.

The communications server can also be used to perform EDI transactions.EDI, or Electronic Data Interexchange, is an electronic commerceapplication that allows organizations to share business informationvia computer systems rather than mailing large documents, suchas proposals and contracts, through the postal system. You simplypost the information on your comm server and other computers candial in to retrieve a copy. The reverse application would be configuringyour comm server to automatically dial into another organization'sEDI comm server to fetch the latest documents. EDI is an effectiveway to gather or disseminate information to large numbers of peoplewith minimum effort.

World Wide Web Servers

Many organizations are using the Internet World Wide Web (WWW)service to provide information about their organization's servicesand products. The WWW format displays electronic documents orpages with graphics that can be accessed using the TCP/IP protocol.The WWW service uses a protocol called Hypertext Transfer Protocolor HTTP. This page layout is useful in displaying pictures ofproducts, places, or people, and the accompanying text can beset up to link one page or Web site to another page or site. Asyou view the page, the link text is highlighted so that when youclick on the text with your mouse, you jump to the other pageor Web site automatically.

Typically, a Web server is accessed across the Internet, but itcan be used within a LAN without Internet connectivity. You stillmust have TCP/IP software running on the workstations. A Web servercan be set up on your file server, but if the Web site becomesextremely busy (particularly if it is connected to the Internet),the serving of files and other services to your users may slowdown.

Network Connectivity Hardware

There is some additional hardware that you can use in local areanetworking, some of which I mentioned earlier. This includes thehubs that are used in the twisted pair Ethernet LAN. The hub isthe device to which all the twisted pair LAN computers are connected.These hubs come in a variety of makes and models, and selectingone can be based largely on price. However, as with the servers,you probably don't want the cheapest one in your LAN. A good ruleis to eliminate the cheapest and the most expensive models andwhat's left will probably serve the average LAN pretty well.

A variation on the hub concept is the switch. A switch has portsjust as the hub does, but the switch is smarter than a hub. Theswitch learns all the addresses (the unique network identifyingnumbers that are on each network interface card) of all the computerson the LAN. The switch knows what address can be found on eachof its ports. When you issue a login or connect request to a server,the switch sees the request and connects the calling port directlyto the called port. This is similar to the phone company's switching.The advantage is that theconnect request doesn't have to circulatearound the network looking for the right address. The switch knowswhich port the server is on and connects you directly.

Because the switch is handling all the connections, fewer transmissionproblems occur, and more time is spent sending data instead ofcollision messages. Switches were first used for Ethernet networks,but now there are switches for Token Ring LANs as well. If youare supporting the heavy-duty applications, such as Computer AidedDesign and Software Engineering packages on your LAN, or if yourLAN is simply very busy with several users, you may be a candidatefor a switch. If users are complaining that it takes forever tosend and receive data and that the collision lights on your equipmentare constantly flickering, you may need a switched LAN.

There is a lot of leeway in the day-to-day operations of the localarea network. Every little connector and cable need not be thesame type or engineered down to the micrometer. Every workstationneed not be set up exactly the same in terms of operating systemand hardware performance. Establishing solid maintenance schedulesand backup routines will go a long way in keeping things runningsmooth.

Summary

You've just gotten through an overview of one of the more intimidatingaspects of intranets-the network hardware. This is a subject thatwhole books are written on (try Understanding Local Area Networksor Understanding Data Communications, 5th Edition, bothfrom Sams Publishing), so you have some more learning to do.

But by now you should have more than a little knowledge of LANs.In the next chapter, you'll expand upon this knowledge and learnthe principles of taking your LAN out into the big, wide worldto meet other LANs-forming a wide area