Home > Articles > Networking

This chapter is from the book

LAN Technologies

The most common network architectures are the following:

  • Ethernet

  • Token ring


The Institute of Electrical and Electronic Engineers (IEEE) has produced a set of standards for LAN architectures. Although token ring and ethernet were both created before the IEEE standards, the IEEE specifications for IEEE 802.3 (ethernet) and IEEE 802.5 (token ring) now provide vendor-neutral standards for these important LAN technologies.

The following sections will examine ethernet and token ring in greater detail, along with another LAN technology: FDDI.


Ethernet and its newer sibling Fast Ethernet are the LAN technologies most commonly used today. Ethernet has become popular because of its modest price; Ethernet cable is inexpensive and easily installed. Ethernet network adapters and Ethernet hardware components are also relatively inexpensive.

On ethernet networks, all computers share a common transmission medium. Ethernet uses an access method called Carrier Sense Multiple Access with Collision Detect (CSMA/CD) for determining when a computer is free to transmit data on to the access medium. Using CSMA/CD, all computers monitor the transmission medium and wait until the line is available before transmitting. If two computers try to transmit at the same time, a collision occurs. The computers then stop, wait for a random time interval, and attempt to transmit again.

CSMA/CD can be compared to the protocol followed by a room full of polite people. Someone who wants to speak first listens to determine whether anybody else is currently speaking (this is the Carrier Sense). If two people start speaking at the same moment, both people will detect the problem, stop speaking, and wait before speaking again (this is Collision Detect).

Traditional ethernet works well under light-to-moderate use but suffers from high collision rates under heavy use. Some of the newer ethernet variants, which might include intelligent hubs or switches, support higher traffic levels. You'll learn more about hubs and switches in Hour 9, "Network Hardware."

Ethernet is capable of using a variety of media. Ethernet networks typically operate at baseband speeds of either 10Mbps or 100Mbps. 1000Mbps (Gigabit) Ethernet systems are now available and might soon be common. Table 3.1 lists terms used to identify cabling media, speeds, and maximum distances. Wireless ethernet is also becoming popular. 10BASE-2 and 10BASE-5 coaxial ethernet networks were once very common. Figure 3.3 shows a coaxial 10BASE-2 network. Note that the computers are attached to a single cable that acts as the shared transmission medium. In recent years, hub-based ethernet variants such as 10BASE-T (see Figure 3.4) have become vastly more popular. On a 10BASE-T network, the computers are attached to a central hub. 10BASE-2 and 10BASE-T might appear to be dissimilar, but internally they are both still ethernet.

Table 3.1 Ethernet Media Technology

Technology Name

Media Type

Operating Speed

Maximum Distance


Thin coax

10 megabits

185 meters


Thick coax

10 megabits

500 meters



10 megabits

100 meters


Fiber optic

10 megabits

2,000 meters



100 megabits

100 meters


Fiber optic

100 megabits

2,000 meters

The versatile ethernet architecture even lends itself to wireless networking. Wireless ethernet is becoming increasingly popular, and will become even more popular in the coming years as network hardware evolves to accommodate the wireless revolution. You might wonder how an architecture that is so focused on specifying the type, length, and configuration of its cable could get by with no cable at all. When you think about it, though, the broadcast nature of ethernet communication is quite compatible with the roving, free-flowing wireless paradigm. You'll learn more about wireless networking in Hour 22, "Wireless Networks."

Figure 3.3Figure 3.3 A 10BASE-2 coaxial ethernet network.

Figure 3.4Figure 3.4 A 10BASE-T hub-based ethernet network.

Token Ring

Token ring technology uses a completely different concept for allowing network adapters to transmit data on the media. This access method is known as token passing.

Under the token passing access method, the computers on the LAN are connected so that data is passed around the network in a logical ring (see Figure 3.5). The token ring configuration calls for the computers to be wired to a central hub called a MAU or MSAU. Figure 3.5 might not look like a ring, but the MSAU is wired so that the data passes from one computer to the next in a circular motion. The computers pass a packet of data called a token around the network. Only the computer that holds the token can transmit a message on to the ring.

Figure 3.5Figure 3.5 A token ring.

Token ring is technically more sophisticated than ethernet, and it includes a number of built-in diagnosis and correction mechanisms that can help troubleshoot network problems. Also, because data is transmitted in a more orderly fashion, token ring does not suffer as badly under heavy data traffic. Almost everything about token ring is more expensive than ethernet by comparison—the cable, the network adapter cards, and the other components as well.

Token ring typically operates at either 4Mbps or 16Mbps. It is also available at 100Mbps.

Token ring has declined in popularity in recent years, although the ring topology that evolved around Token Ring has found its way into other high-end technologies such as FDDI, which you'll learn about in the next section.


Fiber Distributed Data Interface (FDDI) is an expensive LAN technology that employs a pair of fiber-optic rings. One ring is considered primary and the second ring is there to replace the primary ring in the event of a breakdown. FDDI uses a token passing access method similar to token ring.

Like token ring, FDDI also has error-detection and correction capabilities. In a normally operating FDDI ring, the token passes by each machine every so often. If the token is not seen within the maximum amount of time that it takes to circulate the largest ring, it indicates a problem has occurred such as a broken cable.

Fiber-optic cable such as the cable used with FDDI can support very large volumes of data over large distances.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020